Drag chain ends now pp3_colour and explode.

Added blower_exit_offset().
Fixed corner shape and exit dimensions.
Updated images and readme.

core.scad

@@ -18,7 +18,7 @@
 //
 
 //
-// Include this file to use the miniumum library plus screws, nuts and washers
+// Include this file to use the minimum library plus screws, nuts and washers
 //
 include <utils/core/core.scad>
 //

global_defs.scad

@@ -33,7 +33,7 @@ $exploded       = is_undef($explode)         ? 0      : $explode;         // 1 f
 layer_height    = is_undef($layer_height)    ? 0.25   : $layer_height;    // layer heigth when printing
 extrusion_width = is_undef($extrusion_width) ? 0.5    : $extrusion_width; // filament width when printing
 nozzle          = is_undef($nozzle)          ? 0.45   : $nozzle;          // 3D printer nozzle
-cnc_bit_r       = is_undef($cnc_bit_r)       ? 1.2    : $cnc_bit_r;       // miniumum tool radius when milling 2D objects
+cnc_bit_r       = is_undef($cnc_bit_r)       ? 1.2    : $cnc_bit_r;       // minimum tool radius when milling 2D objects
 pp1_colour      = is_undef($pp1_colour)      ? [0, 146/255, 0] : $pp1_colour; // printed part colour 1, RepRap logo colour
 pp2_colour      = is_undef($pp2_colour)      ? "red"  : $pp2_colour;      // printed part colour 2
 pp3_colour      = is_undef($pp3_colour)      ? "blue" : $pp3_colour;      // printed part colour 3

lib.scad

@@ -29,6 +29,7 @@ include <vitamins/batteries.scad>
 include <vitamins/blowers.scad>
 include <vitamins/bulldogs.scad>
 include <vitamins/buttons.scad>
+include <vitamins/cameras.scad>
 include <vitamins/components.scad>
 include <vitamins/displays.scad>
 include <vitamins/extrusions.scad>
@@ -42,6 +43,7 @@ include <vitamins/ldrs.scad>
 include <vitamins/leadnuts.scad>
 include <vitamins/led_meter.scad>
 include <vitamins/light_strips.scad>
+include <vitamins/magnets.scad>
 include <vitamins/mains_sockets.scad>
 include <vitamins/modules.scad>
 include <vitamins/panel_meters.scad>
@@ -52,6 +54,7 @@ include <vitamins/ring_terminals.scad>
 include <vitamins/rails.scad>
 include <vitamins/rod.scad>
 include <vitamins/scs_bearing_blocks.scad>
+include <vitamins/shaft_couplings.scad>
 include <vitamins/sheets.scad>
 include <vitamins/sk_brackets.scad>
 include <vitamins/spools.scad>
@@ -83,6 +86,7 @@ use <utils/rounded_cylinder.scad>
 use <utils/dogbones.scad>
 use <utils/tube.scad>
 use <utils/quadrant.scad>
+use <utils/gears.scad>
 use <utils/hanging_hole.scad>
 use <utils/fillet.scad>
 use <utils/rounded_polygon.scad>

libtest.scad

@@ -17,6 +17,23 @@
 // If not, see <https://www.gnu.org/licenses/>.
 //
 
+//!# NopSCADlib
+//! An ever expanding library of parts modelled in OpenSCAD useful for 3D printers and enclosures for electronics, etc.
+//!
+//! It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and some utilities.
+//! There are also Python scripts to generate Bills of Materials (BOMs),
+//! STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
+//! instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md).
+//!
+//! A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
+//!
+//! For more examples of what it can make see the [gallery](gallery/readme.md).
+//!
+//! The license is GNU General Public License v3.0, see [COPYING](COPYING).
+//!
+//! See [usage](docs/usage.md) for requirements, installation instructions and a usage guide.
+//!
+//! <img src="libtest.png" width="100%"/>
 //
 // This file shows all the parts in the library.
 //
@@ -29,10 +46,13 @@ use <tests/blowers.scad>
 use <tests/bulldogs.scad>
 use <tests/buttons.scad>
 use <tests/cable_strips.scad>
+use <tests/cameras.scad>
+use <tests/camera_housing.scad>
 use <tests/circlips.scad>
 use <tests/components.scad>
 use <tests/d_connectors.scad>
 use <tests/displays.scad>
+use <tests/drag_chain.scad>
 use <tests/extrusions.scad>
 use <tests/extrusion_brackets.scad>
 use <tests/fans.scad>
@@ -49,6 +69,7 @@ use <tests/LEDs.scad>
 use <tests/light_strips.scad>
 use <tests/linear_bearings.scad>
 use <tests/LED_meters.scad>
+use <tests/magnets.scad>
 use <tests/microswitches.scad>
 use <tests/modules.scad>
 use <tests/nuts.scad>
@@ -66,13 +87,14 @@ use <tests/rod.scad>
 use <tests/screws.scad>
 use <tests/SCS_bearing_blocks.scad>
 use <tests/sealing_strip.scad>
+use <tests/shaft_couplings.scad>
 use <tests/sheets.scad>
 use <tests/SK_brackets.scad>
 use <tests/spades.scad>
 use <tests/springs.scad>
 use <tests/SSRs.scad>
 use <tests/stepper_motors.scad>
-use <tests/swiss_clips.scad>
+use <tests/Swiss_clips.scad>
 use <tests/toggles.scad>
 use <tests/transformers.scad>
 use <tests/tubings.scad>
@@ -115,17 +137,17 @@ cable_grommets_y = 0;
 translate([x5, cable_grommets_y])
     cable_grommets();
 
-translate([x5, cable_grommets_y + 50])
-    feet();
+translate([x5 + 80, cable_grommets_y])
+    ribbon_clamps();
 
-translate([x5, cable_grommets_y + 75])
+translate([x5, cable_grommets_y + 60])
     fixing_blocks();
 
-translate([x5, cable_grommets_y + 100])
+translate([x5, cable_grommets_y + 90])
     corner_blocks();
 
 translate([x5, cable_grommets_y + 150])
-    ribbon_clamps();
+    feet();
 
 translate([x5 + 70, cable_grommets_y + 150])
     screw_knobs();
@@ -270,8 +292,9 @@ translate([x1, leadnuts_y])
 
 leds_y = 0;
 carriers_y = leds_y + 40;
-spades_y = carriers_y + 40;
-buttons_y = spades_y + 40;
+magnets_y = carriers_y + 40;
+spades_y = magnets_y + 20;
+buttons_y = spades_y + 20;
 jacks_y = buttons_y + 40;
 microswitches_y = jacks_y + 40;
 rockers_y = microswitches_y + 40;
@@ -287,6 +310,9 @@ translate([x2 + 35, leds_y])
 translate([x2 + 8, carriers_y])
     carriers();
 
+translate([x2, magnets_y])
+    magnets();
+
 translate([x2 + 20, carriers_y])
     led_meters();
 
@@ -334,9 +360,15 @@ translate([x3 + 70, veroboard_y + 30])
 translate([x3 + 140, veroboard_y + 20])
     pcb_mounts();
 
+translate([x3 + 170, veroboard_y + 16])
+    cameras();
+
 translate([x3, d_connectors_y])
     d_connectors();
 
+translate([x3 + 170, d_connectors_y - 10])
+    camera_housings();
+
 translate([x3, iecs_y])
     iecs();
 
@@ -381,13 +413,17 @@ sk_brackets_y = extrusion_brackets_y + 80;
 kp_pillow_blocks_y = sk_brackets_y + 50;
 scs_bearing_blocks_y = kp_pillow_blocks_y + 60;
 
-translate([x4 + 150, belts_y + 58]) {
+translate([x4 + 200, belts_y + 58]) {
     belt_test();
 
     translate([0, 60])
         opengrab_test();
+
 }
 
+translate([x4 + 175, belts_y, -20])
+    drag_chains();
+
 translate([x4, rails_y + 130])
     rails();
 
@@ -403,6 +439,9 @@ translate([x4, sk_brackets_y])
 translate([x4, extrusion_brackets_y])
     extrusion_brackets();
 
+translate([x4 + 120, extrusion_brackets_y])
+    shaft_couplings();
+
 translate([x4, scs_bearing_blocks_y])
     scs_bearing_blocks();
 

printed/box.scad

@@ -31,29 +31,29 @@
 //!
 //! Normally the side sheets are the same type but they can be overridden individually as long as the substitute has the same thickness.
 //
-include <../utils/core/core.scad>
+include <../core.scad>
 use <../vitamins/sheet.scad>
-use <../vitamins/screw.scad>
-use <../vitamins/washer.scad>
 use <../vitamins/insert.scad>
 use <../utils/quadrant.scad>
+use <../utils/round.scad>
 
 bezel_clearance = 0.2;
 sheet_end_clearance = 1;
 sheet_slot_clearance = 0.2;
 
-function box_screw(type)     = type[0]; //! Screw type to be used at the corners
-function box_wall(type)      = type[1]; //! Wall thickness of 3D parts
-function box_sheets(type)    = type[2]; //! Sheet type used for the sides
-function box_top_sheet(type) = type[3]; //! Sheet type for the top
-function box_base_sheet(type)= type[4]; //! Sheet type for the bottom
-function box_feet(type)      = type[5]; //! True to enable feet on the bottom bezel
-function box_width(type)     = type[6]; //! Internal width
-function box_depth(type)     = type[7]; //! Internal depth
-function box_height(type)    = type[8]; //! Internal height
+function box_screw(type)       = type[0]; //! Screw type to be used at the corners
+function box_shelf_screw(type) = type[1]; //! Screw type to hold a shelf
+function box_wall(type)        = type[2]; //! Wall thickness of 3D parts
+function box_sheets(type)      = type[3]; //! Sheet type used for the sides
+function box_top_sheet(type)   = type[4]; //! Sheet type for the top
+function box_base_sheet(type)  = type[5]; //! Sheet type for the bottom
+function box_feet(type)        = type[6]; //! True to enable feet on the bottom bezel
+function box_width(type)       = type[7]; //! Internal width
+function box_depth(type)       = type[8]; //! Internal depth
+function box_height(type)      = type[9]; //! Internal height
 
-function box(screw, wall, sheets, top_sheet, base_sheet, size, feet = false) = //! Construct a property list for a box.
- concat([screw, wall, sheets, top_sheet, base_sheet, feet], size);
+function box(screw, wall, sheets, top_sheet, base_sheet, size, feet = false, shelf_screw = M3_dome_screw) = //! Construct a property list for a box.
+ concat([screw, shelf_screw, wall, sheets, top_sheet, base_sheet, feet], size);
 
 function box_bezel_clearance(type) = bezel_clearance;
 
@@ -62,6 +62,7 @@ function box_profile_overlap(type) = 3 + sheet_end_clearance / 2;
 
 function box_washer(type) = screw_washer(box_screw(type));
 function box_insert(type) = screw_insert(box_screw(type));
+function box_shelf_insert(type) = screw_insert(box_shelf_screw(type));
 
 function box_hole_inset(type) = washer_radius(box_washer(type)) + 1;
 function box_insert_r(type) = insert_hole_radius(box_insert(type));
@@ -90,23 +91,32 @@ function box_bezel_height(type, bottom) = //! Bezel height for top or bottom
 
 grill_hole = 5;
 grill_gap = 1.9;
-module grill(width, height, r = 1000, poly = false, h = 0) { //! A staggered array of 5mm holes to make grills in sheets. Can be constrained to be circular. Set ```poly``` ```true``` for printing, ```false``` for milling.
+
+function box_grill_hole_r() = grill_hole / 2;
+
+module grill_hole_positions(width, height, r = 1000) {
     nx = floor(width / (grill_hole + grill_gap));
     xpitch = width / nx;
     ny = floor(height / ((grill_hole + grill_gap) * cos(30)));
     ypitch = height / ny;
 
+    for(y = [0 : ny - 1], x = [0 : nx - 1 - (y % 2)]) {
+        $x = -width / 2 + (x + 0.5 + (y % 2) / 2) * xpitch;
+        $y = -height / 2 + (y + 0.5) * ypitch;
+        if(sqrt(sqr($x) + sqr($y)) + grill_hole / 2 <= r)
+            translate([$x, $y])
+                children();
+    }
+}
+
+module grill(width, height, r = 1000, poly = false, h = 0) { //! A staggered array of 5mm holes to make grills in sheets. Can be constrained to be circular. Set ```poly``` ```true``` for printing, ```false``` for milling.
     extrude_if(h)
-        for(y = [0 : ny - 1], x = [0 : nx - 1 - (y % 2)]) {
-            x = -width / 2 + (x + 0.5 + (y % 2) / 2) * xpitch;
-            y = -height / 2 + (y + 0.5) * ypitch;
-            if(sqrt(sqr(x) + sqr(y)) + grill_hole / 2 <= r)
-                translate([x, y])
-                    if(poly)
-                        poly_circle(r = grill_hole / 2);
-                    else
-                        circle(d = grill_hole);
-        }
+        if(poly)
+            grill_hole_positions(width, height, r)
+                poly_circle(r = grill_hole / 2);
+        else
+            grill_hole_positions(width, height, r)
+                circle(d = grill_hole);
 }
 
 module box_corner_profile_2D(type) { //! The 2D shape of the corner profile.
@@ -178,6 +188,15 @@ module box_corner_profile_section(type, section, sections) { //! Generates inter
     }
 }
 
+module box_corner_profile_sections(type, section, sections) { //! Generate four copies of a corner profile section
+    stl("box_corner_profile");
+    offset = box_boss_r(type) + 1;
+    for(i = [0 : 3])
+        rotate(i * 90)
+            translate([offset, offset])
+                box_corner_profile_section(type, section, sections);
+}
+
 module box_corner_quadrants(type, width, depth)
     for(corner = [0:3]) {
         x = [-1,1,1,-1][corner];
@@ -261,10 +280,11 @@ dowel_length = 20;
 dowel_wall = extrusion_width * 3;
 dowel_h_wall = layer_height * 6;
 
-
 module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlocking sections of the bezel to allow it to be bigger than the printer
-    w = (box_width(type) + 2 * box_outset(type)) / cols;
-    h = (box_depth(type) + 2 * box_outset(type)) / rows;
+    tw = box_width(type) + 2 * box_outset(type);
+    w = tw / cols;
+    th = box_depth(type) + 2 * box_outset(type);
+    h = th / rows;
     bw = box_outset(type) - bezel_clearance / 2;
     bw2 = box_outset(type) + box_inset(type);
 
@@ -339,7 +359,7 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
         render() difference() {
             union() {
                 clip(xmin = 0, xmax = w, ymin = 0, ymax = h)
-                    translate([box_width(type) / 2 + box_outset(type) - x * w, box_depth(type) / 2 + box_outset(type) - y * h, box_profile_overlap(type)])
+                    translate([tw / 2 - x * w, th / 2 - y * h, box_profile_overlap(type)])
                         box_bezel(type, bottom);
 
                 if(x < cols - 1 && y == 0)
@@ -399,7 +419,6 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
     }
 }
 
-
 module box_screw_hole_positions(type)
     for(x = [-1, 1], y = [-1, 1])
         translate([x * (box_width(type) / 2 - box_hole_inset(type)), y * (box_depth(type) / 2 - box_hole_inset(type))])
@@ -442,6 +461,96 @@ module box_shelf_blank(type, sheet = false) { //! Generates a 2D template for a
     }
 }
 
+module box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = undef) { //! Place children at the shelf screw positions
+    w = is_undef(wall) ? box_wall(type) : wall;
+    insert = box_shelf_insert(type);
+    translate_z(-insert_boss_radius(insert, w))
+        for(p = screw_positions)
+            multmatrix(p)
+                translate_z(thickness)
+                    children();
+}
+
+module box_shelf_bracket(type, screw_positions, wall = undef) { //! Generates a shelf bracket, the first optional child is a 2D cutout and the second 3D cutouts
+    stl("shelf_bracket");
+    w = is_undef(wall) ? box_wall(type) : wall;
+    insert = box_shelf_insert(type);
+    lip = 2 * insert_boss_radius(insert, w);
+    width = insert_length(insert) + w;
+
+    module shape()
+        difference() {
+            square([box_width(type), box_depth(type)], center = true);
+
+            offset(bezel_clearance / 2)
+                box_corner_quadrants(type, box_width(type), box_depth(type));
+
+            if($children)
+                hflip()
+                    children();
+        }
+
+    module boss()
+        translate_z(-width + eps)
+            linear_extrude(width - 2 * eps)
+                hull() {
+                    circle4n(r = lip / 2 - eps);
+
+                    translate([-lip / 2, -lip / 2 + eps])
+                        square([lip, eps]);
+                }
+
+    difference() {
+        union() {
+            linear_extrude(w)
+                difference() {
+                    shape()
+                        if($children)
+                            children(0);
+
+                    round(2) offset(-width)
+                        shape()
+                            if($children)
+                                children(0);
+                }
+
+            linear_extrude(lip)
+                difference() {
+                    shape()
+                        if($children)
+                            children(0);
+
+                    offset(-w)
+                        shape()
+                            if($children)
+                                children(0);
+                }
+
+            hflip()
+                box_shelf_screw_positions(type, screw_positions, 0, w)
+                    boss();
+        }
+        if($children > 1)
+            hflip()
+                children(1);
+
+        hflip()
+            box_shelf_screw_positions(type, screw_positions, 0, w)
+                insert_hole(insert, counterbore = 1, horizontal = true);
+    }
+}
+
+module box_shelf_bracket_section(type, rows, cols, x, y) { //! Generates sections of the shelf bracket to allow it to be bigger than the printer
+    tw = box_width(type);
+    w = tw / cols;
+    th = box_depth(type);
+    h = th / rows;
+
+    clip(xmin = 0, xmax = w, ymin = 0, ymax = h)
+        translate([tw / 2 - x * w, th / 2 - y * h])
+            children();
+}
+
 module box_left_blank(type, sheet = false) { //! Generates a 2D template for the left sheet, ```sheet``` can be set to override the type
     dxf("box_left");
 

printed/butt_box.scad

@@ -110,12 +110,9 @@ function fixing_block_positions(type) = let(
 
 function side_holes(type) = [for(p = fixing_block_positions(type), q = fixing_block_holes(bbox_screw(type))) p * q];
 
-module drill_holes(type, t)
-    for(list = [corner_holes(type), side_holes(type)], p = list)
-        let(q = t * p)
-            if(abs(transform([0, 0, 0], q).z) < eps)
-                multmatrix(q)
-                    drill(screw_clearance_radius(bbox_screw(type)), 0);
+module bbox_drill_holes(type, t)
+    position_children(concat(corner_holes(type), side_holes(type)), t)
+        drill(screw_clearance_radius(bbox_screw(type)), 0);
 
 module bbox_base_blank(type) { //! 2D template for the base
     dxf(str(bbox_name(type), "_base"));
@@ -123,7 +120,7 @@ module bbox_base_blank(type) { //! 2D template for the base
     difference() {
         sheet_2D(bbox_base_sheet(type), bbox_width(type), bbox_depth(type), 1);
 
-        drill_holes(type, translate(bbox_height(type) / 2));
+        bbox_drill_holes(type, translate(bbox_height(type) / 2));
     }
 }
 
@@ -136,7 +133,7 @@ module bbox_top_blank(type) { //! 2D template for the top
         translate([0, t / 2])
             sheet_2D(bbox_top_sheet(type), bbox_width(type) + 2 * t, bbox_depth(type) + t);
 
-        drill_holes(type, translate(-bbox_height(type) / 2));
+        bbox_drill_holes(type, translate(-bbox_height(type) / 2));
     }
 }
 
@@ -154,7 +151,7 @@ module bbox_left_blank(type, sheet = false) { //! 2D template for the left side
         translate([-t / 2, -bb / 2])
             sheet_2D(subst_sheet(type, sheet), bbox_depth(type) + t, bbox_height(type) + bb);
 
-        drill_holes(type, rotate([0, 90, 90]) * translate([bbox_width(type) / 2, 0]));
+        bbox_drill_holes(type, rotate([0, 90, 90]) * translate([bbox_width(type) / 2, 0]));
     }
 }
 
@@ -168,7 +165,7 @@ module bbox_right_blank(type, sheet = false) { //! 2D template for the right sid
         translate([t / 2, -bb / 2])
             sheet_2D(subst_sheet(type, sheet), bbox_depth(type) + t, bbox_height(type) + bb);
 
-        drill_holes(type, rotate([0, 90, 90]) * translate([-bbox_width(type) / 2, 0]));
+        bbox_drill_holes(type, rotate([0, 90, 90]) * translate([-bbox_width(type) / 2, 0]));
     }
 }
 
@@ -183,7 +180,7 @@ module bbox_front_blank(type, sheet = false, width = 0) { //! 2D template for th
         translate([0, (bt - bb) / 2])
             sheet_2D(subst_sheet(type, sheet), max(bbox_width(type) + 2 * t, width), bbox_height(type) + bb + bt);
 
-        drill_holes(type, rotate([-90, 0, 0]) * translate([0, bbox_depth(type) / 2]));
+        bbox_drill_holes(type, rotate([-90, 0, 0]) * translate([0, bbox_depth(type) / 2]));
     }
 }
 
@@ -197,7 +194,7 @@ module bbox_back_blank(type, sheet = false) { //! 2D template for the back
         translate([0, -bb / 2])
             sheet_2D(subst_sheet(type, sheet), bbox_width(type), bbox_height(type) + bb);
 
-        drill_holes(type, rotate([-90, 0, 0]) * translate([0, -bbox_depth(type) / 2]));
+        bbox_drill_holes(type, rotate([-90, 0, 0]) * translate([0, -bbox_depth(type) / 2]));
     }
 }
 

printed/camera_housing.scad

@@ -0,0 +1,392 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Housings for PCB cameras.
+//
+include <../core.scad>
+include <../vitamins/cameras.scad>
+use <../vitamins/pcb.scad>
+use <../vitamins/insert.scad>
+
+wall = 1.75;
+min_wall = 2 * extrusion_width;
+clearance = 0.2;
+
+connector_size = [23, 6, 2.65]; // Worst case size of flat flex connector
+
+cam_back_clearance = round_to_layer(1.5);    // Clearance for components on the back of the pcb
+cam_back_overlap = 1;                        // How much the back overlaps the edge of the pcb
+cam_back_wall = min_wall;
+
+function cam_front_clearance(cam) = round_to_layer(camera_connector_size(cam).z + clearance);
+
+function cam_back_size(cam) = let(
+    pcb = camera_pcb(cam),
+    pcb_size = pcb_size(pcb),
+    nut = screw_nut(pcb_screw(pcb)),
+    holes = [for(h = pcb_holes(pcb)) pcb_coord(pcb, h).x],
+    pitch = max(holes) - min(holes),
+    length = pitch + 2 * (nut_radius(nut) + min_wall),
+    width = pcb_size.y + (length - pcb_size.x) * cos(30)
+    ) [length, width, wall + max(connector_size.z, cam_back_clearance + nut_trap_depth(nut))];
+
+
+function cam_front_size(cam) = cam_back_size(cam) + [ //! Outside dimensions of the case
+    2 * (wall + clearance),
+    2 * (wall + clearance),
+    pcb_thickness(camera_pcb(cam)) + cam_front_clearance(cam) + wall
+];
+
+hinge_screw = M2_cap_screw;
+hinge_nut = screw_nut(hinge_screw);
+hinge_screw_length = 12;
+
+hinge_r = nut_trap_radius(hinge_nut) + 3 * extrusion_width;
+hinge_h = wall + nut_trap_depth(hinge_nut);
+hinge_offset = hinge_r + 1;
+
+bracket_screw = M3_dome_screw;
+
+function cam_screw_length(cam) = let(
+    front = cam_front_size(cam),
+    screw = pcb_screw(camera_pcb(cam)),
+    nut = screw_nut(screw)
+    ) screw_longer_than(front.z + washer_thickness(screw_washer(screw)) - nut_trap_depth(nut) + nut_thickness(nut, true));
+
+function hinge_z(cam) = cam_screw_length(cam) - hinge_r;
+
+module cam_holes(cam) {
+    pcb = camera_pcb(cam);
+    lens_y = camera_lens_offset(cam).y;
+    two_holes = !!len([for (h = pcb_holes(pcb)) if(abs(pcb_coord(pcb, h).y - lens_y) < 1) true]);
+    pcb_screw_positions(pcb)                                                    // screw holes
+        if($i > 1 || !two_holes)
+            children();
+}
+
+module rpi_camera_focus_ring_stl() { //! Focus ring the glue onto RPI lens
+    stl("rpi_camera_focus_ring");
+
+    rad = 15 / 2;
+    hole_r1 = 2.5 / 2;
+    hole_r2 = 5 / 2;
+    thickness = 3;
+    flutes = 8;
+    angle = 180 / flutes;
+    x = rad / (sin(angle / 2) + cos(angle / 2));
+    r = x * sin(angle / 2);
+
+    difference() {
+        linear_extrude(height = thickness, convexity = 5)
+            difference() {
+                union() {
+                    circle(x);
+                    for(i = [0 : flutes - 1])
+                        rotate([0, 0, 2 * angle * i])
+                            translate([x, 0])
+                                circle(r);
+                }
+                for(i = [0 : flutes - 1])
+                    rotate([0, 0, 2 * angle * i + angle])
+                        translate([x, 0])
+                            circle(r);
+            }
+        hull() {
+            poly_cylinder(r = hole_r1, h = 0.1, center = true);
+
+            translate([0, 0, thickness])
+                poly_cylinder(r = hole_r2, h = 0.1, center = true);
+        }
+    }
+}
+
+module camera_back(cam) { //! Make the STL for a camera case back
+    stl(str("camera_back_", cam[0]));
+    pcb = camera_pcb(cam);
+    back = cam_back_size(cam);
+    screw = pcb_screw(pcb);
+    nut = screw_nut(screw);
+
+    translate_z(back.z)
+        hflip()
+            difference() {
+                translate_z(back.z / 2)
+                    cube(back, center = true);
+
+                translate([0, -cam_back_overlap])
+                    cube([pcb_length(pcb) - 2 * cam_back_overlap, pcb_width(pcb), 2 * cam_back_clearance], center = true);
+
+                translate([0, -pcb_width(pcb) / 2])
+                    cube([connector_size.x + 2 * clearance, 2 * connector_size.y + 1, 2 * round_to_layer(connector_size.z + clearance)], center = true);
+
+                translate_z(back.z)
+                    cam_holes(cam)
+                        hflip()
+                            nut_trap(screw, nut, supported = true);
+            }
+}
+
+module camera_front(cam, hinge = 0) { //! Make the STL for a camera case front
+    stl(str("camera_front_", cam[0]));
+    front = cam_front_size(cam);
+    back = cam_back_size(cam);
+    pcb = camera_pcb(cam);
+    pcb_size = pcb_size(pcb);
+    lens_offset = camera_lens_offset(cam);
+    screw = pcb_screw(pcb);
+
+    shelf = front.z - back.z;
+
+    connector_slot = connector_size + 2 * [clearance, 0, layer_height];
+    rad = wall;
+    led_hole_r = 1;
+    led_clearance = [5,   2, 1 * 2];
+    res_clearance = [3.5, 2, 1 * 2];
+
+    conn_pos = camera_connector_pos(cam);
+    conn = camera_connector_size(cam);
+    sensor_length = conn_pos.y + conn.y / 2 - lens_offset.y + clearance;
+
+    module hinge_pos()
+        if(!is_undef(hinge))
+            rotate(hinge * 90)
+                translate([0, (hinge ? front.x * hinge : front.y) / 2 + hinge_offset, hinge_r])
+                    children();
+
+    difference() {
+        union() {
+            hull()
+                for(x = [-1, 1], y = [-1, 1])
+                    translate([x * (front.x / 2 - rad), y * (front.y / 2 - rad)])
+                        hull() {    // 3D truncated teardrop gives radiused edges without exceeding 45 degree overhang
+                            translate_z(front.z - 1)
+                                cylinder(r = rad, h = 1);
+
+                            translate_z(rad)
+                                sphere(rad);
+
+                            cylinder(r = rad * (sqrt(2) - 1), h = eps);
+                        }
+
+            hinge_pos()
+                hull() {
+                    rotate([-90, 0, -90])
+                        teardrop(r = hinge_r, h = hinge_h, center = false);
+
+                    translate([0, -10, -hinge_r])
+                        cube([hinge_h, eps, 2 * hinge_r]);
+                }
+        }
+
+        hinge_pos()
+            rotate([90, 0, 90])
+                teardrop_plus(r = screw_clearance_radius(hinge_screw), h = 100, center = true);
+
+        translate_z(front.z / 2 + shelf - layer_height)                                 // recess for the back
+            cube([back.x + 2 * clearance, back.y + 2 * clearance, front.z], center = true);
+
+        translate_z(front.z / 2 + shelf - pcb_size.z)                                   // recess for PCB
+            cube([pcb_size.x + 2 * clearance, pcb_size.y + 2 * clearance, front.z], center = true);
+
+        translate_z(shelf)
+            hflip() {
+                pcb_component_position(pcb, "smd_led")                                  // clearance for LED
+                    cube(led_clearance, center = true);
+
+                pcb_component_position(pcb, "smd_res")                                  // clearance for resistor
+                    cube(res_clearance, center = true);
+            }
+
+        translate([conn_pos.x, lens_offset.y + sensor_length / 2, shelf - pcb_size.z])  // clearance for sensor connector
+            cube([conn.x + 2 * clearance, sensor_length, 2 * cam_front_clearance(cam)], center = true);
+
+        translate([0, -front.y / 2, shelf + front.z / 2])                               // slot for connector
+            cube([connector_slot.x, connector_slot.y, front.z], center = true);
+
+        translate_z(cam_back_clearance + layer_height)
+            cam_holes(cam)
+                rotate(90)
+                    poly_cylinder(r = screw_clearance_radius(screw), h = 100, center = true);
+
+        translate_z(shelf - pcb_size.z)
+            hflip()
+                camera_lens(cam, clearance);
+
+        hflip()
+            pcb_component_position(pcb, "smd_led")
+                rotate(45)
+                    poly_cylinder(r = led_hole_r, h = 100, center = true);              // hole for led
+    }
+}
+
+function bracket_thickness(cam) = max(wall, min(3.5, hinge_z(cam) - hinge_r - 1));
+
+module camera_bracket_screw_positions(cam) { //! Position children at the bracket screw positions
+    r = washer_radius(screw_washer(bracket_screw)) + 0.5;
+    wide = bracket_thickness(cam) == wall;
+    pitch = wide ? cam_front_size(cam).x / 2 - r : hinge_h + 1 + r;
+
+    for(side = [-1, 1])
+        translate([side * pitch, 0])
+            children();
+}
+
+module camera_bracket_position(cam) //! Position children at the bracket position
+    translate([0,  cam_front_size(cam).y / 2 + hinge_offset])
+        children();
+
+module camera_bracket(cam) { //! Make the STL for the camera bracket
+    stl(str("camera_bracket_", cam[0]));
+
+    t = bracket_thickness(cam);
+    z = hinge_z(cam);
+    translate([hinge_h / 2, 0])
+        difference() {
+            hull() {
+                translate_z(eps / 2)
+                    cube([hinge_h, 2 * hinge_r, eps], center = true);
+
+                translate_z(z)
+                    rotate([0, 90, 0])
+                        cylinder(r = hinge_r, h = hinge_h, center = true);
+            }
+            translate([hinge_h / 2, 0, z])
+                rotate([90, 0, 90])
+                    nut_trap(hinge_screw, screw_nut(hinge_screw), horizontal = true);
+        }
+
+    linear_extrude(t)
+        difference() {
+            hull()
+                camera_bracket_screw_positions(cam)
+                    circle(washer_radius(screw_washer(bracket_screw)) + 0.5);
+
+            camera_bracket_screw_positions(cam)
+                poly_circle(screw_clearance_radius(bracket_screw));
+        }
+}
+
+module camera_assembly(cam, angle = 0) //! Camera case assembly
+assembly(str("camera_", cam[0])) {
+    front = cam_front_size(cam);
+    screw = pcb_screw(camera_pcb(cam));
+    nut = screw_nut(screw);
+    screw_length = cam_screw_length(cam);
+    hinge_z = hinge_z(cam);
+    hinge_pos = [0, front.y / 2  + hinge_offset, -hinge_r];
+
+    camera_bracket_position(cam) {
+        nut = screw_nut(hinge_screw);
+
+        stl_colour(pp1_colour) render()
+            camera_bracket(cam);
+
+        translate([-hinge_h, 0, hinge_z(cam)])
+            rotate([-90, 0, 90]) {
+                vflip()
+                    translate_z(2 * hinge_h - nut_trap_depth(nut))
+                        nut(nut, true);
+
+                screw_and_washer(hinge_screw, screw_longer_than(2 * hinge_h));
+            }
+    }
+
+    translate_z(hinge_z(cam) + hinge_r)
+        translate(hinge_pos)
+            rotate([-angle, 0, 0])
+                translate(-hinge_pos) {
+                    translate_z(cam_back_size(cam).z - front.z)
+                        camera(cam);
+
+                    stl_colour(pp1_colour) render()
+                        translate_z(-front.z)
+                            camera_back(cam);
+
+                    cam_holes(cam) {
+                        screw_and_washer(screw, screw_length);
+
+                        translate_z(-front.z + nut_trap_depth(nut))
+                            vflip()
+                                nut(nut, true);
+                    }
+
+                    *translate(camera_lens_offset(cam))
+                        translate_z(1.5)
+                            stl_colour(pp1_colour) render()
+                                rpi_camera_focus_ring_stl();
+
+                    stl_colour(pp2_colour) render()
+                        hflip()
+                            camera_front(cam, 0);
+                }
+}
+
+module camera_fastened_assembly(cam, thickness, angle = 0) {
+    camera_assembly(cam, angle);
+
+    camera_bracket_position(cam)
+        camera_bracket_screw_positions(cam) {
+            nut = screw_nut(bracket_screw);
+            washer = screw_washer(bracket_screw);
+            t = bracket_thickness(cam);
+            screw_length = screw_longer_than(thickness + t + nut_thickness(nut, true) + 2 * washer_thickness(washer));
+            vflip()
+                translate_z(thickness)
+                    screw_and_washer(bracket_screw, screw_length);
+
+            translate_z(t)
+                nut_and_washer(nut, true);
+        }
+}
+
+module camera_back_rpi_camera_stl()    camera_back(rpi_camera);
+module camera_back_rpi_camera_v1_stl() camera_back(rpi_camera_v1);
+module camera_back_rpi_camera_v2_stl() camera_back(rpi_camera_v2);
+
+module camera_front_rpi_camera_stl()    camera_front(rpi_camera);
+module camera_front_rpi_camera_v1_stl() camera_front(rpi_camera_v1);
+module camera_front_rpi_camera_v2_stl() camera_front(rpi_camera_v2);
+
+module camera_bracket_rpi_camera_stl()    camera_bracket(rpi_camera);
+module camera_bracket_rpi_camera_v1_stl() camera_bracket(rpi_camera_v1);
+module camera_bracket_rpi_camera_v2_stl() camera_bracket(rpi_camera_v2);
+
+module camera_rpi_camera_assembly()    camera_assembly(rpi_camera);
+module camera_rpi_camera_v1_assembly() camera_assembly(rpi_camera_v1);
+module camera_rpi_camera_v2_assembly() camera_assembly(rpi_camera_v2);
+
+module camera_housing(cam) {
+    front = cam_front_size(cam);
+
+    camera_front(cam, 0);
+
+    translate([front.x, 0])
+        camera_back(cam);
+
+    translate([-front.x / 2 - 2 - hinge_r, 0])
+        rotate(90)
+            camera_bracket(cam);
+}
+
+cam = rpi_camera_v2;
+if($preview)
+    camera_fastened_assembly(cam, 3);
+else
+    camera_housing(cam);

printed/door_hinge.scad

@@ -74,7 +74,7 @@ module door_hinge(door_thickness) {                         //! Generates STL fo
                             square([1, thickness + door_thickness]);
                     }
                     translate([dia / 2, thickness + door_thickness / 2])
-                        teardrop(r = screw_clearance_radius(pin_screw), h = 0);
+                        teardrop_plus(r = screw_clearance_radius(pin_screw), h = 0);
                 }
         linear_extrude(thickness)
             difference() {
@@ -127,7 +127,7 @@ module door_hinge_stat_stl() { //! Generates the STL for the stationary part
                             square([dia, 1], center = true);
                     }
                     translate([0, dia / 2 + stat_clearance])
-                        teardrop(r = screw_clearance_radius(pin_screw), h = 0);
+                        teardrop_plus(r = screw_clearance_radius(pin_screw), h = 0);
                }
     }
 }

printed/drag_chain.scad

@@ -0,0 +1,286 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Parametric cable drag chain to limit the bend radius of a cable run.
+//!
+//! Each link has a maximum bend angle of 45&deg;, so the mininium radius is proportional to the link length.
+//!
+//! The travel property is how far it can move in each direction, i.e. half the maximum travel if the chain is mounted in the middle of the travel.
+//
+
+include <../core.scad>
+use <../utils/horiholes.scad>
+use <../utils/maths.scad>
+
+function drag_chain_name(type)        = type[0]; //! The name to allow more than one in a project
+function drag_chain_size(type)        = type[1]; //! The internal size and link length
+function drag_chain_travel(type)      = type[2]; //! X travel
+function drag_chain_wall(type)        = type[3]; //! Side wall thickness
+function drag_chain_bwall(type)       = type[4]; //! Bottom wall
+function drag_chain_twall(type)       = type[5]; //! Top wall
+function drag_chain_screw(type)       = type[6]; //! Mounting screw for the ends
+function drag_chain_screw_lists(type) = type[7]; //! Two lists of four bools to say which screws positions are used
+
+function drag_chain_radius(type) = //! The bend radius at the pivot centres
+    let(s = drag_chain_size(type))
+        s.x / 2 / sin(360 / 16);
+
+function drag_chain_z(type) = //! Outside dimension of a 180 bend
+    let(os = drag_chain_outer_size(type), s = drag_chain_size(type))
+        2 * drag_chain_radius(type) + os.z;
+
+function drag_chain(name, size, travel, wall = 1.6, bwall = 1.5, twall = 1.5, screw = M2_cap_screw, screw_lists = [[1,0,0,1],[1,0,0,1]]) = //! Constructor
+    [name, size, travel, wall, bwall, twall, screw, screw_lists];
+
+clearance = 0.1;
+
+function drag_chain_outer_size(type) =     //! Link outer dimensions
+    let(s = drag_chain_size(type), z = s.z + drag_chain_bwall(type) + drag_chain_twall(type))
+        [s.x + z, s.y + 4 * drag_chain_wall(type) + 2 * clearance, z];
+
+function screw_lug_radius(screw) = //! Radius if a screw lug
+    corrected_radius(screw_clearance_radius(screw)) + 3.1 * extrusion_width;
+
+module screw_lug(screw, h = 0) //! Create a D shaped lug for a screw
+    extrude_if(h, center = false)
+        difference() {
+            r = screw_lug_radius(screw);
+            hull() {
+                circle4n(r);
+
+                translate([-r, -r])
+                    square([2 * r, eps]);
+            }
+            poly_circle(screw_clearance_radius(screw));
+        }
+
+function bool2int(b) = b ? 1 : 0;
+
+module drag_chain_screw_positions(type, end) {//! Place children at the screw positions, end = 0 for the start, 1 for the end
+    r = screw_lug_radius(drag_chain_screw(type));
+    s = drag_chain_size(type);
+    os = drag_chain_outer_size(type);
+    R = os.z / 2;
+    x0 = end ? R + norm([drag_chain_cam_x(type), R - drag_chain_twall(type)]) + clearance + r : r;
+    x1 = end ? os.x - r : os.x - 2 * R - clearance - r;
+    for(i = [0 : 3]) {
+        x = i % 2;
+        y = bool2int(i > 1);
+        if(drag_chain_screw_lists(type)[bool2int(end)][i])
+            translate([(x0 + x1) / 2, 0])
+                mirror([x, 0])
+                    mirror([0, y])
+                        translate([(x1 - x0) / 2,  s.y / 2 + r])
+                            children();
+    }
+}
+
+function drag_chain_cam_x(type) = // how far the cam sticks out
+    let(s = drag_chain_size(type),
+        r =  drag_chain_outer_size(type).z / 2,
+        wall =  drag_chain_wall(type),
+        cam_r = s.x - 2 * clearance - wall - r,  // inner_x_normal - clearance - r
+        twall = drag_chain_twall(type)
+    )   min(sqrt(max(sqr(cam_r) - sqr(r - twall), 0)), r);
+
+
+module drag_chain_link(type, start = false, end = false) { //! One link of the chain, special case for start and end
+    stl(str(drag_chain_name(type), "_drag_chain_link", start ? "_start" : end ? "_end" : ""));
+
+    s = drag_chain_size(type);
+    wall = drag_chain_wall(type);
+    bwall = drag_chain_bwall(type);
+    twall = drag_chain_twall(type);
+    os = drag_chain_outer_size(type);
+    r = os.z / 2;
+    pin_r = r / 2;
+
+    socket_x = r;
+    pin_x = socket_x + s.x;
+
+    outer_normal_x =  pin_x - r - clearance;     // s.x - clearance
+    outer_end_x = end ? os.x : outer_normal_x;
+
+    inner_x = start ? 0 : outer_normal_x - wall; // s.x - clearance - wall
+
+    roof_x_normal = 2 * r - twall;
+    roof_x = start ? 0 : roof_x_normal;
+
+    floor_x = start ? 0 : 2 * r;
+    cam_x = drag_chain_cam_x(type);
+    assert(r + norm([drag_chain_cam_x(type), r - drag_chain_twall(type)]) + clearance <= inner_x || start, "Link must be longer");
+
+    difference() {
+        union() {
+            for(side = [-1, 1])
+                rotate([90, 0, 0]) {
+                    // Outer cheeks
+                    translate_z(side * (os.y / 2 - wall / 2))
+                        linear_extrude(wall, center = true)
+                            difference() {
+                                hull() {
+                                    if(start)
+                                        square([eps, os.z]);
+                                    else
+                                        translate([socket_x, r])
+                                            rotate(180)
+                                                teardrop(r = r, h = 0);
+
+                                    translate([outer_end_x - eps, 0])
+                                        square([eps, os.z]);
+                                }
+                                if(!start)
+                                    translate([socket_x, r])
+                                        horihole(pin_r, r);
+                            }
+                    // Inner cheeks
+                    translate_z(side * (s.y / 2 + wall / 2))
+                        linear_extrude(wall, center = true)
+                            difference() {
+                                union() {
+                                    hull() {
+                                        if(!end) {
+                                            translate([pin_x, r])
+                                                rotate(180)
+                                                    teardrop(r = r, h = 0);
+
+                                            translate([pin_x, twall])
+                                                square([cam_x, eps]);
+                                        }
+                                        else
+                                            translate([os.x - eps, 0])
+                                                square([eps, os.z]);
+
+                                        translate([inner_x, 0])
+                                            square([eps, os.z]);
+                                    }
+                                }
+                                // Cutout for top wall
+                                if(!end)
+                                    intersection() {
+                                        translate([pin_x - r, 0])
+                                            square([3 * r, twall]);  // When straight
+
+                                        translate([pin_x, r])
+                                             rotate(-45)
+                                                translate([-r + roof_x_normal, -r - twall]) // When bent fully
+                                                    square(os.z);
+                                    }
+                            }
+                    // Pin
+                    if(!end)
+                        translate([pin_x, r, side * (s.y / 2 + wall + clearance)])
+                            horicylinder(r = pin_r, z = r, h = 2 * wall);
+
+                    // Cheek joint
+                    translate([inner_x, 0, side * (s.y / 2 + wall) - 0.5])
+                        cube([outer_end_x - inner_x, os.z, 1]);
+                }
+
+            // Roof, actually the floor when printed
+            roof_end = end ? s.x + 2 * r : s.x + r - twall - clearance;
+            translate([roof_x, -s.y / 2 - 0.5])
+                cube([roof_end - roof_x , s.y + 1, twall]);
+
+            translate([roof_x, -os.y / 2 + 0.5])
+                cube([s.x - clearance - roof_x, os.y - 1, twall]);
+
+            // Floor, actually the roof when printed
+            floor_end = end ? s.x + 2 * r : s.x + r;
+            translate([floor_x, -s.y / 2 - wall, os.z - bwall])
+                cube([floor_end - floor_x, s.y + 2 * wall, bwall]);
+
+            translate([floor_x, -os.y / 2 + 0.5,  os.z - bwall])
+                cube([s.x - floor_x - clearance, os.y -1, bwall]);
+
+            if(start || end)
+                drag_chain_screw_positions(type, end)
+                    screw_lug(drag_chain_screw(type), os.z);
+        }
+        if(start || end)
+            translate_z(-eps)
+                drag_chain_screw_positions(type, end)
+                    poly_cylinder(r = screw_clearance_radius(drag_chain_screw(type)), h = os.z + 2 * eps, center = false);
+
+    }
+
+    if(show_supports() && !end) {
+        for(side = [-1, 1]) {
+            w = 2.1 * extrusion_width;
+            translate([s.x + r + cam_x - w / 2, side * (s.y / 2 + wall / 2), twall / 2])
+                cube([w, wall, twall], center = true);
+
+            h = round_to_layer(r - pin_r / sqrt(2));
+            y = s.y / 2  + max(wall + w / 2 + clearance, 2 * wall + clearance - w / 2);
+            translate([s.x + r, side * y, h / 2])
+                cube([pin_r * sqrt(2), w, h], center = true);
+
+            gap = cam_x - pin_r / sqrt(2) + extrusion_width;
+            translate([s.x + r + cam_x - gap / 2, side * (s.y / 2 + wall + clearance / 2), layer_height / 2])
+                cube([gap, 2 * wall + clearance, layer_height], center = true);
+        }
+    }
+}
+
+//! 1. Remove the support material from the links with side cutters.
+//! 1. Clip the links together with the special ones at the ends.
+module drag_chain_assembly(type, pos = 0) { //! Drag chain assembly
+    s = drag_chain_size(type);
+    x = (1 + exploded()) * s.x;
+    r = drag_chain_radius(type) * x / s.x;
+    travel = drag_chain_travel(type);
+    links = ceil(travel / s.x);
+    actual_travel = links * s.x;
+    z = drag_chain_outer_size(type).z;
+
+    zb = z / 2;                                     // z of bottom track
+    c = [actual_travel / 2 + pos / 2, 0, r + zb];   // centre of bend
+
+    points = [                                      // Calculate list of hinge points
+        for(i = 0, p = [0, 0, z / 2 + 2 * r]; i < links + 5;
+            i = i + 1,
+            dx = p.z > c.z ? x : -x,
+            p = max(p.x + dx, p.x) <= c.x ? p + [dx, 0, 0]      // Straight sections
+                  : let(q = circle_intersect(p, x, c, r))
+                        q.x <= c.x ? [p.x - sqrt(sqr(x) - sqr(p.z - zb)), 0, zb] // Transition back to straight
+                                   : q) // Circular section
+        p
+    ];
+    npoints = len(points);
+
+    module link(n)                                  // Position and colour link with origin at the hinge hole
+        translate([-z / 2, 0, -z / 2])
+            stl_colour(n < 0 || n == npoints - 1 ? pp3_colour : n % 2 ? pp1_colour : pp2_colour)
+                drag_chain_link(type, start = n == -1, end = n == npoints - 1);
+
+    assembly(str(drag_chain_name(type), "_drag_chain")) {
+        for(i = [0 : npoints - 2]) let(v = points[i+1] - points[i])
+            translate(points[i])
+                rotate([0, -atan2(v.z, v.x), 0])
+                    link(i);
+
+        translate(points[0] - [x, 0, 0])
+            link(-1);
+
+        translate(points[npoints - 1])
+            hflip()
+                link(npoints - 1);
+    }
+}

printed/ribbon_clamp.scad

@@ -24,69 +24,72 @@ include <../core.scad>
 use <../vitamins/insert.scad>
 use <../vitamins/cable_strip.scad>
 
-wall = 2;
+wall = 1.6;
 min_wall = 2 * extrusion_width;
 screw = M3_cap_screw;
-insert = screw_insert(screw);
-screw_depth = insert_length(insert) + 1;
 
-function ribbon_clamp_hole_pitch(ways) = ribbon_clamp_slot(ways) + 2 * min_wall + 2 * corrected_radius(insert_hole_radius(insert)); //! Hole pitch
-function ribbon_clamp_width() = 2 * (insert_hole_radius(insert) + wall); //! Width
-function ribbon_clamp_length(ways) = ribbon_clamp_hole_pitch(ways) + ribbon_clamp_width(); //! Length given ways
-function ribbon_clamp_height() = screw_depth + 1; //! Height
+function ribbon_clamp_screw_depth(screw = screw) = insert_length(screw_insert(screw)) + 1;
+function ribbon_clamp_hole_pitch(ways, screw = screw) =
+    ribbon_clamp_slot(ways) + 2 * min_wall + 2 * corrected_radius(insert_hole_radius(screw_insert(screw))); //! Hole pitch
 
-module ribbon_clamp_hole_positions(ways, side = undef) //! Place children at hole positions
+function ribbon_clamp_width(screw = screw) = 2 * (insert_hole_radius(screw_insert(screw)) + wall); //! Width
+function ribbon_clamp_length(ways, screw = screw) = ribbon_clamp_hole_pitch(ways, screw) + ribbon_clamp_width(screw); //! Length given ways
+function ribbon_clamp_height(screw = screw) = ribbon_clamp_screw_depth(screw) + 1; //! Height
+
+module ribbon_clamp_hole_positions(ways, screw = screw, side = undef) //! Place children at hole positions
     for(x = is_undef(side) ? [-1, 1] : side)
-        translate([x * ribbon_clamp_hole_pitch(ways) / 2, 0])
+        translate([x * ribbon_clamp_hole_pitch(ways, screw) / 2, 0])
             children();
 
-module ribbon_clamp_holes(ways, h = 20) //! Drill screw holes
-    ribbon_clamp_hole_positions(ways)
+module ribbon_clamp_holes(ways, h = 20, screw = screw) //! Drill screw holes
+    ribbon_clamp_hole_positions(ways, screw)
         drill(screw_clearance_radius(screw), h);
 
-module ribbon_clamp(ways) { //! Generate STL for given number of ways
-    stl(str("ribbon_clamp_", ways));
+module ribbon_clamp(ways, screw = screw) { //! Generate STL for given number of ways
+    screw_d = screw_radius(screw) * 2;
+    stl(str("ribbon_clamp_", ways, screw_d != 3 ? str("_", screw_d) : ""));
 
-    pitch = ribbon_clamp_hole_pitch(ways);
-    d = ribbon_clamp_width();
-    h = ribbon_clamp_height();
-    t = h - ribbon_clamp_slot_depth() - wall;
+    pitch = ribbon_clamp_hole_pitch(ways, screw);
+    d = ribbon_clamp_width(screw);
+    h = ribbon_clamp_height(screw);
+    t = round_to_layer(ribbon_clamp_slot_depth() + wall);
+    insert = screw_insert(screw);
 
     difference() {
         union() {
             hull() {
                 translate_z(h - t / 2)
-                    cube([ribbon_clamp_hole_pitch(ways), d, t], center = true);
+                    cube([ribbon_clamp_hole_pitch(ways, screw), d, t], center = true);
 
                 translate_z(1)
                     cube([pitch, max(wall, d - 2 * (h - t)), 2], center = true);
             }
-            ribbon_clamp_hole_positions(ways, -1)
+            ribbon_clamp_hole_positions(ways, screw, -1)
                 cylinder(d = d, h = h);
 
-            ribbon_clamp_hole_positions(ways,  1)
+            ribbon_clamp_hole_positions(ways, screw, 1)
                 cylinder(d = d, h = h);
-
         }
 
         translate_z(h)
             cube([ribbon_clamp_slot(ways), d + 1, ribbon_clamp_slot_depth() * 2], center = true);
 
-        ribbon_clamp_hole_positions(ways)
+        ribbon_clamp_hole_positions(ways, screw)
             translate_z(h)
                 rotate(22.5)
-                    insert_hole(insert, screw_depth - insert_length(insert));
+                    insert_hole(insert, ribbon_clamp_screw_depth(screw) - insert_length(insert));
     }
 }
 
-module ribbon_clamp_assembly(ways) pose([55, 180, 25])  //! Printed part with inserts in place
-    assembly(str("ribbon_clamp_", ways)) {
-    h = ribbon_clamp_height();
+module ribbon_clamp_assembly(ways, screw = screw) pose([55, 180, 25])  //! Printed part with inserts in place
+    assembly(let(screw_d = screw_radius(screw) * 2)str("ribbon_clamp_", ways, screw_d != 3 ? str("_", screw_d) : "")) {
+    h = ribbon_clamp_height(screw);
+    insert = screw_insert(screw);
 
     stl_colour(pp1_colour) render()
-        translate_z(h) vflip() ribbon_clamp(ways);
+        translate_z(h) vflip() ribbon_clamp(ways, screw);
 
-    ribbon_clamp_hole_positions(ways)
+    ribbon_clamp_hole_positions(ways, screw)
         vflip()
             insert(insert);
 }
@@ -99,20 +102,28 @@ module ribbon_clamp_fastened_assembly(ways, thickness, screw = screw) { //! Clam
     vitamin(str(": Tape self amalgamating silicone ",tape_l," x 25mm"));
 
     washer = screw_washer(screw);
-    screw_length = screw_shorter_than(2 * washer_thickness(washer) + thickness + screw_depth);
+    screw_length = screw_shorter_than(2 * washer_thickness(washer) + thickness + ribbon_clamp_screw_depth(screw));
 
-    ribbon_clamp_assembly(ways);
+    ribbon_clamp_assembly(ways, screw);
 
     color("red") translate_z(tape_thickness / 2)
         cube([tape_l, tape_width, tape_thickness], center = true);
 
-    ribbon_clamp_hole_positions(ways)
+    ribbon_clamp_hole_positions(ways, screw)
         vflip()
            translate_z(thickness)
                 screw_and_washer(screw, screw_length, true);
 }
 
 module ribbon_clamp_20_stl() ribbon_clamp(20);
+module ribbon_clamp_8_2_stl() ribbon_clamp(8, M2_dome_screw);
+module ribbon_clamp_7_2_stl() ribbon_clamp(8, M2_dome_screw);
 
 //! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200&deg;C.
 module ribbon_clamp_20_assembly() ribbon_clamp_assembly(20);
+
+//! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200&deg;C.
+module ribbon_clamp_8_2_assembly() ribbon_clamp_assembly(8, M2_dome_screw);
+
+//! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200&deg;C.
+module ribbon_clamp_7_2_assembly() ribbon_clamp_assembly(8, M2_dome_screw);

scripts/plateup.py

@@ -27,6 +27,7 @@ import c14n_stl
 from set_config import *
 from deps import *
 from shutil import copyfile
+import re
 
 source_dirs = { "stl" : "platters", "dxf" : "panels" }
 target_dirs = { "stl" : "printed",  "dxf" : "routed" }
@@ -38,61 +39,73 @@ def plateup(target, part_type, usage = None):
     top_dir = set_config(target, usage)
     parts_dir = top_dir + part_type + 's'
     target_dir = parts_dir + '/' + target_dirs[part_type]
-    source_dir = top_dir + source_dirs[part_type]
-    deps_dir = source_dir + "/deps"
-    if not os.path.isdir(source_dir):
-        return
-    if not os.path.isdir(target_dir):
-        os.makedirs(target_dir)
-    if not os.path.isdir(deps_dir):
-        os.makedirs(deps_dir)
+    source_dir1 = source_dirs[part_type]
+    source_dir2 = top_dir + source_dirs[part_type]
     #
-    # Decide which files to make
-    #
-    sources = [file for file in os.listdir(source_dir) if file.endswith('.scad')]
-    #
-    # Run OpenSCAD on the source files to make the targets
+    # Loop through source directories
     #
     used = []
-    for src in sources:
-        src_file = source_dir + '/' + src
-        part_file = target_dir + '/' + src[:-4] + part_type
-        dname = deps_name(deps_dir, src)
-        changed = check_deps(part_file, dname)
-        if changed:
-            print(changed)
-            openscad.run("-D$bom=1", "-d", dname, "-o", part_file, src_file)
-            if part_type == 'stl':
-                c14n_stl.canonicalise(part_file)
-            log_name = 'openscad.log'
-        else:
-            log_name = 'openscad.echo'
-            openscad.run_silent("-D$bom=1", "-o", log_name, src_file)
+    all_sources = []
+    for dir in [source_dir1, source_dir2]:
+        if not os.path.isdir(dir):
+            continue
+        if not os.path.isdir(target_dir):
+            os.makedirs(target_dir)
         #
-        # Add the files on the BOM to the used list
+        # Make the deps dir
         #
-        with open(log_name) as file:
-            for line in file.readlines():
-                if line.startswith('ECHO: "~') and line.endswith('.' + part_type + '"\n'):
-                    used.append(line[8:-2])
-    #
-    # Copy file that are not included
-    #
+        deps_dir = dir + "/deps"
+        if not os.path.isdir(deps_dir):
+            os.makedirs(deps_dir)
+        #
+        # Decide which files to make
+        #
+        sources = [file for file in os.listdir(dir) if file.endswith('.scad')]
+        all_sources += sources
+        #
+        # Run OpenSCAD on the source files to make the targets
+        #
+        for src in sources:
+            src_file = dir + '/' + src
+            part_file = target_dir + '/' + src[:-4] + part_type
+            dname = deps_name(deps_dir, src)
+            changed = check_deps(part_file, dname)
+            if changed:
+                print(changed)
+                openscad.run("-D$bom=1", "-d", dname, "-o", part_file, src_file)
+                if part_type == 'stl':
+                    c14n_stl.canonicalise(part_file)
+                log_name = 'openscad.log'
+            else:
+                log_name = 'openscad.echo'
+                openscad.run_silent("-D$bom=1", "-o", log_name, src_file)
+            #
+            # Add the files on the BOM to the used list
+            #
+            with open(log_name) as file:
+                for line in file.readlines():
+                    match = re.match(r'^ECHO: "~(.*?\.' + part_type + r').*"$', line)
+                    if match:
+                        used.append(match.group(1))
     copied = []
-    for file in os.listdir(parts_dir):
-        if file.endswith('.' + part_type) and not file in used:
-            src = parts_dir + '/' + file
-            dst = target_dir + '/' + file
-            if mtime(src) > mtime(dst):
-                print("Copying %s to %s" % (src, dst))
-                copyfile(src, dst)
-            copied.append(file)
-    #
-    # Remove any cruft
-    #
-    targets = [file[:-4] + part_type for file in sources]
-    for file in os.listdir(target_dir):
-        if file.endswith('.' + part_type):
-            if not file in targets and not file in copied:
-                print("Removing %s" % file)
-                os.remove(target_dir + '/' + file)
+    if all_sources:
+        #
+        # Copy files that are not included
+        #
+        for file in os.listdir(parts_dir):
+            if file.endswith('.' + part_type) and not file in used:
+                src = parts_dir + '/' + file
+                dst = target_dir + '/' + file
+                if mtime(src) > mtime(dst):
+                    print("Copying %s to %s" % (src, dst))
+                    copyfile(src, dst)
+                copied.append(file)
+        #
+        # Remove any cruft
+        #
+        targets = [file[:-4] + part_type for file in all_sources]
+        for file in os.listdir(target_dir):
+            if file.endswith('.' + part_type):
+                if not file in targets and not file in copied:
+                    print("Removing %s" % file)
+                    os.remove(target_dir + '/' + file)

scripts/tests.py

@@ -97,7 +97,6 @@ def tests(tests):
     for dir in [deps_dir, png_dir, bom_dir]:
         if not os.path.isdir(dir):
             os.makedirs(dir)
-    doc_name = "readme.md"
     index = {}
     bodies = {}
     done = []
@@ -108,19 +107,33 @@ def tests(tests):
     #
     png_name = "libtest.png"
     scad_name = "libtest.scad"
-    if not os.path.isfile(png_name):
-        openscad.run(colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,50,0,340,500", "--autocenter", "--viewall", "-o", png_name, scad_name);
-        do_cmd(["magick", png_name, "-trim", "-resize", "1280", "-bordercolor", background, "-border", "10", png_name])
+    if os.path.isfile(scad_name):
+        libtest = True
+        lib_blurb = scrape_blurb(scad_name)
+        if not os.path.isfile(png_name):
+            openscad.run(colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,50,0,340,500", "--autocenter", "--viewall", "-o", png_name, scad_name);
+            do_cmd(["magick", png_name, "-trim", "-resize", "1280", "-bordercolor", background, "-border", "10", png_name])
+    else:
+        #
+        # Project tests so just a title
+        #
+        libtest = False
+        project = ' '.join(word[0].upper() + word[1:] for word in os.path.basename(os.getcwd()).split('_'))
+        lib_blurb = '#' + project + ' Tests\n'
+
+    doc_base_name = "readme" if libtest else "tests"
+    doc_name = doc_base_name + ".md"
     #
     # List of individual part files
     #
-    scads = [i for i in sorted(os.listdir(scad_dir), key = lambda s: s.lower()) if i[-5:] == ".scad"]
 
+    scads = [i for i in sorted(os.listdir(scad_dir), key = lambda s: s.lower()) if i[-5:] == ".scad"]
+    types = []
     for scad in scads:
         base_name = scad[:-5]
         if not tests or base_name in tests:
             done.append(base_name)
-            print(base_name)
+            print('\n'+base_name)
             cap_name = base_name[0].capitalize() + base_name[1:]
             base_name = base_name.lower()
             scad_name = scad_dir + '/' + scad
@@ -132,29 +145,42 @@ def tests(tests):
             if is_plural(base_name) and os.path.isfile(vits_name):
                 objects_name = vits_name
 
-            locations = [
-                ('vitamins/' + depluralise(base_name) + '.scad', 'Vitamins'),
-                ('printed/' + base_name + '.scad',               'Printed'),
-                ('utils/' + base_name + '.scad',                 'Utilities'),
-                ('utils/core/' + base_name + '.scad',            'Core Utilities'),
-            ]
+            locations = []
+            if os.path.isdir('vitamins'):
+                locations.append(('vitamins/' + depluralise(base_name) + '.scad', 'Vitamins'))
+            if os.path.isdir('printed'):
+                locations.append(('printed/' + base_name + '.scad',               'Printed'))
+            if os.path.isdir('utils'):
+                locations.append(('utils/' + base_name + '.scad',                 'Utilities'))
+            if libtest and os.path.isdir('utils/core'):
+                locations.append(('utils/core/' + base_name + '.scad',            'Core Utilities'))
 
             for name, type in locations:
                 if os.path.isfile(name):
                     impl_name = name
                     break
             else:
-                print("Can't find implementation!")
-                continue
+                if libtest:
+                    print("Can't find implementation!")
+                    continue
+                else:
+                    type = 'Tests'                         # OK when testing part of a project
+                    impl_name = None
 
-            vsplit = "AJR" + chr(ord('Z') + 1)
-            vtype = locations[0][1]
-            types = [vtype + ' ' + vsplit[i] + '-'  + chr(ord(vsplit[i + 1]) - 1) for i in range(len(vsplit) - 1)] + [loc[1] for loc in locations[1 :]]
-            if type == vtype:
-                for i in range(1, len(vsplit)):
-                    if cap_name[0] < vsplit[i]:
-                         type = types[i - 1]
-                         break
+            if libtest:
+                vsplit = "AJR" + chr(ord('Z') + 1)
+                vtype = locations[0][1]
+                types = [vtype + ' ' + vsplit[i] + '-' + chr(ord(vsplit[i + 1]) - 1) for i in range(len(vsplit) - 1)] + [loc[1] for loc in locations[1 :]]
+                if type == vtype:
+                    for i in range(1, len(vsplit)):
+                        if cap_name[0] < vsplit[i]:
+                             type = types[i - 1]
+                             break
+            else:
+                if not types:
+                    types = [loc[1] for loc in locations]   # No need to split up the vitamin list
+                    if not type in types:                   # Will happen when implementation is not found and type is set to Tests
+                        types.append(type)
 
             for t in types:
                 if not t in bodies:
@@ -250,24 +276,7 @@ def tests(tests):
         usage()
 
     with open(doc_name, "wt") as doc_file:
-        print('# NopSCADlib', file = doc_file)
-        print('''\
-An ever expanding library of parts modelled in OpenSCAD useful for 3D printers and enclosures for electronics, etc.
-
-It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and
-some utilities. There are also Python scripts to generate Bills of Materials (BOMs),
- STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
-instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md). A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
-
-For more examples of what it can make see the [gallery](gallery/readme.md).
-
-The license is GNU General Public License v3.0, see [COPYING](COPYING).
-
-See [usage](docs/usage.md) for requirements, installation instructions and a usage guide.
-
-<img src="libtest.png" width="100%"/>\n
-''', file = doc_file)
-
+        print(lib_blurb, file = doc_file)
         print('## Table of Contents<a name="top"/>', file = doc_file)
         print('<table><tr>', file = doc_file)
         n = 0
@@ -288,10 +297,10 @@ See [usage](docs/usage.md) for requirements, installation instructions and a usa
         for type in types:
             for line in bodies[type]:
                 print(line, file = doc_file)
-    with open("readme.html", "wt") as html_file:
-        do_cmd("python -m markdown -x tables readme.md".split(), html_file)
+    with open(doc_base_name + ".html", "wt") as html_file:
+        do_cmd(("python -m markdown -x tables " + doc_name).split(), html_file)
     times.print_times()
-    do_cmd('codespell -L od readme.md'.split())
+    do_cmd(('codespell -L od ' + doc_name).split())
 
 if __name__ == '__main__':
     for arg in sys.argv[1:]:

tests/PCB.scad

@@ -58,8 +58,12 @@ test_pcb = ["TestPCB", "Test PCB",
     // components
     [
         [ 20, -5, 180, "trimpot10"],
-        [ 20, -15,  0, "trimpot10", true],
-        [ 10,  2,   0, "smd_led", LED0805, "red"],
+        [ 20, -15,  90, "trimpot10", true],
+        [ 10,  2,   90, "smd_led", LED0805, "red"],
+        [ 13,  2,   90, "smd_led", LED0603, "orange"],
+        [ 16,  2,   90, "smd_res", RES1206, "1K"],
+        [ 19,  2,   90, "smd_res", RES0805, "1K"],
+        [ 22,  2,   90, "smd_res", RES0603, "1K"],
         [ 10,  10,   0, "2p54header", 4, 1],
         [ 25,  10,   0, "2p54header", 5, 1, false, "blue" ],
         [ 10,  20,   0, "2p54boxhdr", 4, 2],
@@ -82,16 +86,20 @@ test_pcb = ["TestPCB", "Test PCB",
         [  5, 218, 180, "hdmi"],
         [  3, 235, 180, "mini_hdmi"],
         [  6, 175, 180, "uSD", [12, 11.5, 1.4]],
+
+        [ 65,   9,   0, "link", inch(0.4)],
         [ 65,  12,   0, "ax_res", res1_8, 1000],
         [ 65,  17,   0, "ax_res", res1_4, 10000],
         [ 65,  22,   0, "ax_res", res1_2, 100000],
 
+        [ 80,   9,   0, "link", inch(0.2), inch(0.4)],
         [ 80,  12,   0, "ax_res", res1_8, 1000000, 1, inch(0.1)],
         [ 80,  17,   0, "ax_res", res1_4, 100,     2, inch(0.1)],
         [ 80,  22,   0, "ax_res", res1_2, 10,     10, inch(0.2)],
 
         [ 60,   3,   0, "flex"],
-        [ 50,  15,   0, "flat_flex"],
+        [ 50,  15, -90, "flat_flex"],
+        [ 40,  15, -90, "flat_flex", true],
         [ 60,  35,   0, "D_plug", DCONN9],
 
         [ 50,  50,   0, "molex_hdr", 2],
@@ -113,7 +121,8 @@ test_pcb = ["TestPCB", "Test PCB",
         [ 70, 130, 180, "term35", 3, "lime"],
         [ 50, 150,   0, "transition", 5],
         [ 50, 160,   0, "block", 10, 5, 8, "orange"],
-        [ 50, 170,   0, "button_6mm"],
+        [ 45, 170,   0, "button_6mm"],
+        [ 55, 170,   0, "button_4p5mm"],
         [ 50, 185,   0, "microswitch", small_microswitch],
         [ 52, 200,   0, "pcb", 11, TMC2130 ],
         [ 80, 200,   0, "pdip", 24, "27C32", true, inch(0.6) ],

tests/SMDs.scad

@@ -21,9 +21,14 @@ use <../utils/layout.scad>
 
 include <../vitamins/smds.scad>
 
-module smds()
-    layout([for(l = smd_leds) smd_led_size(l).x], 1)
-        smd_led(smd_leds[$i], ["green", "blue", "red"][$i % 3]);
+module smds() {
+    layout([for(r = smd_resistors) smd_res_size(r).x], 1)
+        smd_resistor(smd_resistors[$i], ["1R0", "10M", "100K"][$i % 3]);
+
+    translate([0, 3])
+        layout([for(l = smd_leds) smd_led_size(l).x], 1)
+            smd_led(smd_leds[$i], ["green", "blue", "red"][$i % 3]);
+}
 
 if($preview)
     smds();

tests/belts.scad

@@ -23,46 +23,52 @@ use <../vitamins/insert.scad>
 use <../utils/layout.scad>
 
 module belt_test() {
-    p1 = [75,  -50];
     p2 = [-75, -50];
     p3 = [-75, 100];
     p4 = [75,  100];
 
-    p5 = [75  - pulley_pr(GT2x20ob_pulley) - pulley_pr(GT2x16_plain_idler),  -pulley_pr(GT2x16_plain_idler)];
-    p6 = [-75 + pulley_pr(GT2x20ob_pulley) + pulley_pr(GT2x16_plain_idler),  -pulley_pr(GT2x16_plain_idler)];
+    p5 = [75  + pulley_pr(GT2x20ob_pulley) - pulley_pr(GT2x16_plain_idler), +pulley_pr(GT2x16_plain_idler)];
+    p6 = [-75 + pulley_pr(GT2x20ob_pulley) + pulley_pr(GT2x16_plain_idler), -pulley_pr(GT2x16_plain_idler)];
 
-    translate(p1) pulley_assembly(GT2x20ob_pulley);
-    translate(p2) pulley_assembly(GT2x20ob_pulley);
-    translate(p3) pulley_assembly(GT2x20_toothed_idler);
-    translate(p4) pulley_assembly(GT2x20_toothed_idler);
+    module pulleys(flip = false) {
+        translate(p2) rotate([0, flip ? 180 : 0, 0]) pulley_assembly(GT2x20ob_pulley);
+        translate(p3) pulley_assembly(GT2x20_toothed_idler);
+        translate(p4) pulley_assembly(GT2x20_toothed_idler);
+        translate(p5) {
+            pulley = GT2x16_toothed_idler;
+            screw = find_screw(hs_cs_cap, pulley_bore(pulley));
+            insert = screw_insert(screw);
 
-    translate(p5) {
-        pulley = GT2x16_plain_idler;
-        screw = find_screw(hs_cs_cap, pulley_bore(pulley));
-        insert = screw_insert(screw);
-
-        pulley_assembly(pulley);
-        translate_z(pulley_height(pulley) + pulley_offset(pulley) + screw_head_depth(screw, pulley_bore(pulley)))
-            screw(screw, 20);
-
-        translate_z(pulley_offset(pulley) - insert_length(insert))
-            vflip()
-                insert(insert);
+            hflip(flip) {
+                pulley_assembly(pulley);
+                translate_z(pulley_height(pulley) + pulley_offset(pulley) + screw_head_depth(screw, pulley_bore(pulley)))
+                    screw(screw, 20);
 
+                translate_z(pulley_offset(pulley) - insert_length(insert))
+                    vflip()
+                        insert(insert);
+            }
+        }
+        translate(p6) pulley_assembly(GT2x16_plain_idler);
     }
-    translate(p6) pulley_assembly(GT2x16_plain_idler);
 
-    path = [ [p1.x, p1.y, pulley_pr(GT2x20ob_pulley)],
-             [p5.x, p5.y, -pulley_pr(GT2x16_plain_idler)],
+    path = [ [p5.x, p5.y, pulley_pr(GT2x16_plain_idler)],
              [p6.x, p6.y, -pulley_pr(GT2x16_plain_idler)],
              [p2.x, p2.y, pulley_pr(GT2x20ob_pulley)],
              [p3.x, p3.y, pulley_pr(GT2x20ob_pulley)],
              [p4.x, p4.y, pulley_pr(GT2x20ob_pulley)]
            ];
-    belt = GT2x6;
-    belt(belt, path, 80, [0,  belt_pitch_height(belt) - belt_thickness(belt) / 2]);
 
-    translate([-25, 0])
+    belt = GT2x6;
+    belt(belt, path, 80, [0,  0]);
+    pulleys();
+    translate_z(20)
+        hflip() {
+            belt(belt, path, 80, [0,  0], belt_colour = grey(90), tooth_colour = grey(50));
+            pulleys(flip=true);
+        }
+
+    translate([-25, 0, 10])
         layout([for(b = belts) belt_width(b)], 10)
             rotate([0, 90, 0])
                 belt(belts[$i], [[0, 0, 20], [0, 1, 20]], belt_colour = $i%2==0 ? grey(90) : grey(20), tooth_colour = $i%2==0 ? grey(70) : grey(50));

tests/camera_housing.scad

@@ -0,0 +1,33 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../core.scad>
+use <../utils/layout.scad>
+
+use <../printed/camera_housing.scad>
+
+include <../vitamins/cameras.scad>
+
+use <../vitamins/pcb.scad>
+
+module camera_housings()
+    layout([for(c = cameras) pcb_length(camera_pcb(c))], 15, false) let(c = cameras[$i])
+        camera_fastened_assembly(c, 3);
+
+if($preview)
+    camera_housings();

tests/cameras.scad

@@ -0,0 +1,31 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../core.scad>
+use <../utils/layout.scad>
+
+include <../vitamins/cameras.scad>
+
+use <../vitamins/pcb.scad>
+
+module cameras()
+    layout([for(c = cameras) pcb_length(camera_pcb(c))], 15, false) let(c = cameras[$i])
+        camera(c);
+
+if($preview)
+    cameras();

tests/catenary.scad

@@ -0,0 +1,56 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+l = 250; // [1: 1000]
+x = 200; // [1: 1000]
+y = 50; //[-500 : 500]
+
+include <../utils/core/core.scad>
+use <../utils/catenary.scad>
+use <../utils/sweep.scad>
+use <../utils/annotation.scad>
+
+module catenaries() {
+    //
+    // catenary curve path from control points
+    //
+    curve = [for(p = catenary_points(l, x, y)) [p.x, p.y, 0]];
+    //
+    // Draw the curve
+    //
+    r = 0.5;
+    sweep(curve, circle_points(r, $fn = 64));
+    //
+    // Minimum Z
+    //
+    min_z = catenary_points(l, x, y, 0);
+
+    color("blue") {
+        translate([min_z.x, min_z.y + r])
+            rotate([-90, 0, 0])
+                arrow();
+
+        translate([min_z.x, min_z.y - r])
+            rotate([90, 0, 0])
+                arrow();
+    }
+}
+
+if($preview)
+    rotate(is_undef($bom) ? 0 : [70, 0, 315])
+        catenaries();

tests/drag_chain.scad

@@ -0,0 +1,59 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+// Link length between hinges
+x = 10; //[8 : 30]
+
+// Link inner width
+y = 10; //[5 : 30]
+
+// Link inner height
+z = 5;  //[4 : 11]
+// Side wall thickness
+wall = 1.6; //[0.9: 0.1: 3]
+// Bottom wall thickness
+bwall = 1.5; //[1: 0.25: 3]
+// Top wall thickness
+twall = 1.5; //[1: 0.25: 3]
+// Max travel in each direction
+travel = 100;
+// Current position
+pos = 50; // [-100 : 1 : 100]
+
+include <../core.scad>
+use <../printed/drag_chain.scad>
+
+include <../vitamins/leadnuts.scad>
+
+drag_chain = drag_chain("x", [x, y, z], travel, wall = wall, bwall = bwall, twall = twall);
+
+module drag_chains()
+    drag_chain_assembly(drag_chain, pos);
+
+if($preview)
+    drag_chains();
+else {
+    drag_chain_link(drag_chain);
+
+    translate([-x * 2, 0])
+        drag_chain_link(drag_chain, start = true);
+
+    translate([x * 2, 0])
+        drag_chain_link(drag_chain, end = true);
+}

tests/foot.scad

@@ -21,14 +21,14 @@ use <../printed/foot.scad>
 
 module feet()
     if($preview) {
-        translate([50, 0])
+        translate([40, 0])
             foot_assembly(3);
 
         translate([foot_diameter(insert_foot()) / 2, 0])
             fastened_insert_foot_assembly(3);
     }
     else {
-        translate([50, 0])
+        translate([40, 0])
             foot();
 
         insert_foot();

tests/gears.scad

@@ -0,0 +1,66 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../utils/core/core.scad>
+use <../utils/gears.scad>
+
+// left gear teeth
+z1 = 39; // [7 : 1 : 99]
+
+// Right gear teeth
+z2 = 7; // [7 : 1 : 99]
+
+//  Modulus
+m = 2.0; // [0.1 : 0.1 : 5.0]
+
+// Pressure angle
+pa = 20; // [14.5, 20, 22.5, 25]
+
+$show_numbers = false;
+
+module gears() {
+    color(pp1_colour)
+        rotate(-$t * 360)
+            linear_extrude(eps, center = true, convexity = z1)
+                difference() {
+                    involute_gear_profile(m, z1, pa);
+
+                    circle(r = m * z1 / 10);
+                }
+
+    color(pp2_colour)
+        translate([centre_distance(m, z1, z2, pa), 0])
+            rotate(180 + 180 / z2 + $t * 360 * z1 / z2)
+               linear_extrude(eps, center = true, convexity = z2)
+                    difference() {
+                         involute_gear_profile(m, z2, pa);
+
+                         circle(r = m * z2 / 10);
+                    }
+
+    z3 = floor((z1 + z2) / PI);
+    angle = -$t * 360 + 90 - floor(z1 / 4) * 360 / z1; // Line up the rack 1/4 turn around the gear
+    pitch = m * PI;
+    color(pp3_colour)
+        translate([(angle % ((z3 / z1) * 360)) / 360 * z1 * pitch, -centre_distance(m, z1, 0, pa)])
+            linear_extrude(eps, center = true)
+                involute_rack_profile(m, z3, 3 * m, pa);
+}
+
+rotate(is_undef($bom) ? 0 : [70, 0, 315])
+    gears();

tests/global.scad

@@ -29,6 +29,23 @@ module globals() {
         translate([50, 0])
             right_triangle(10, 20, 0);
     }
+    assert(slice("ABCD")    == "ABCD");
+    assert(slice("ABCD", 1) == "BCD");
+    assert(slice("ABCD", 2) == "CD");
+    assert(slice("ABCD", 3) == "D");
+    assert(slice("ABCD", 4) == "");
+    assert(slice("ABCD", 1, -1) == "BC");
+    assert(slice("ABCD", 2, -1) == "C");
+    assert(slice("ABCD", 3, -1) == "");
+    assert(slice("ABCD", 4, -1) == "");
+    assert(slice("ABCD", 0, -1) == "ABC");
+    assert(slice("ABCD", 0, -2) == "AB");
+    assert(slice("ABCD", 0, -3) == "A");
+    assert(slice("ABCD", 0, -4) == "");
+    assert(slice("ABCD", 0,  0) == "");
+    assert(slice("ABCD", 0,  1) == "A");
+    assert(slice("ABCD", 0,  2) == "AB");
+    assert(slice("ABCD", 0,  3) == "ABC");
 }
 
 rotate([70, 0, 315]) globals();

tests/horiholes.scad

@@ -0,0 +1,94 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+$layer_height = 0.25;
+include <../utils/core/core.scad>
+use <../utils/horiholes.scad>
+
+show_disc = true;
+use_horihole = true;
+thickness = 6;
+length = 60;
+height = 20;
+overlap_x = 15;
+overlap_y = 10;
+
+module hole_positions() {
+    x0 = (length - 40) / 2;
+    for($i = [0 : 4], $z = 5 + $i * layer_height / 5, $r = 3)
+        translate([x0 + $i * 10, $z])
+            children();
+
+    for($i = [0 : 4], $z = 15 + $i * layer_height / 5, $r = 0.5 + $i / 2)
+        translate([x0 + $i * 10, $z])
+            children();
+}
+
+module horiholes_stl(t = thickness) {
+    rotate([90, 0, 0])
+        difference() {
+            linear_extrude(t, center = true) {
+                difference() {
+                    square([length, height]);
+
+                    hole_positions()
+                        if(use_horihole)
+                            horihole($r, $z);
+                        else
+                            teardrop_plus(h = 0, r = $r);
+                }
+            }
+        }
+    if(t == thickness)
+        translate([length / 2, 0])
+            rounded_rectangle([length + 2 * overlap_x, thickness + 2 * overlap_y, 2], 5);
+}
+
+module horiholes() {
+    stl_colour(pp1_colour)
+        rotate([-90, 0, 0])
+            horiholes_stl(eps);
+
+    if(show_disc)
+        hole_positions()
+            color(silver)
+                cylinder(r = $r, h = eps, center = true, $fn = 360);
+
+    hole_positions()
+        color("blue")
+            horicylinder(r = $r, z = $z, h = 2 * eps, center = true, $fn = 360);
+
+    hole_positions()
+        color("red")
+            linear_extrude(3 * eps, center = true)
+                intersection() {
+                    difference() {
+                        square(8, center = true);
+
+                        horihole($r, $z);
+                    }
+
+                    circle($r, $fn = 360);
+                }
+}
+
+if($preview)
+    rotate(is_undef($bom) ? 0 : [70, 0, 315])
+        horiholes();
+else
+    horiholes_stl();

tests/hot_ends.scad

@@ -25,7 +25,7 @@ module hot_ends()
     layout([for(h = hot_ends) 40])
         translate([-20, 0])
             rotate(90)
-                hot_end(hot_ends[$i], 3);
+                hot_end(hot_ends[$i], 3, bowden = $i == 3);
 
 if($preview)
     hot_ends();

tests/magnets.scad

@@ -0,0 +1,29 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../core.scad>
+use <../utils/layout.scad>
+
+include <../vitamins/magnets.scad>
+
+module magnets()
+    layout([for(m = magnets) magnet_od(m)], 5)
+        magnet(magnets[$i]);
+
+if($preview)
+    magnets();

tests/maths.scad

@@ -69,6 +69,33 @@ module maths() {
     // Test Euler
     //
     assert(euler(rotate(r)) == r, "euler() failed");
+    //
+    // Circle intersect
+    //
+    r1 = 10;
+    c1 = [50, 0, 10];
+    r2 = 20;
+    c2 = [67, 0, 0];
+    p1 = circle_intersect(c1, r1, c2, r2);
+    p2 = circle_intersect(c2, r2, c1, r1);
+
+    rotate(90) {
+        color(grey(90))
+            translate(c1) rotate([90, 0, 0]) cylinder(r = r1, h = 4 * eps, center = true);
+
+        color(grey(80))
+            translate(c2) rotate([90, 0, 0]) cylinder(r = r2, h = eps, center = true);
+
+        color("red")
+            translate(p1) rotate([90, 0, 0]) cylinder(r = 0.1, h = 6 * eps, center = true);
+
+        color("blue")
+            translate(p2) rotate([90, 0, 0]) cylinder(r = 0.1, h = 6 * eps, center = true);
+
+        translate(p1) arrow();
+
+        translate(p2) vflip() arrow();
+    }
 }
 
 rotate(45)

tests/opengrab.scad

@@ -21,11 +21,11 @@ include <../utils/core/core.scad>
 use <../vitamins/opengrab.scad>
 
 module opengrab_test() {
-    opengrab_target();
-
     rotate(45)
-        translate_z(opengrab_target_thickness())
-            opengrab();
+        opengrab_target();
+
+    translate_z(opengrab_target_thickness())
+        opengrab();
 }
 
 if($preview)

tests/pin_headers.scad

@@ -23,26 +23,56 @@ include <../vitamins/pin_headers.scad>
 
 pins = 10;
 
-module pin_headers()
+module pin_headers() {
     layout([for(p = pin_headers) hdr_pitch(p) * pins], 15) {
         idc_transition(pin_headers[$i], 10);
 
         translate([0, 20])
-            pin_header(pin_headers[$i], 10, 2, right_angle = true);
+            pin_header(pin_headers[$i], 3, 2, right_angle = true);
+
+        translate([-10, 20])
+            pin_header(pin_headers[$i], 3, 1, right_angle = true);
+
+         translate([10, 20])
+            pin_header(pin_headers[$i], 3, 3, right_angle = true);
+
+        translate([0, 30])
+            pin_header(pin_headers[$i], 8, 1);
 
         translate([0, 40])
             pin_header(pin_headers[$i], 10, 2);
 
+        translate([0, 50])
+            box_header(pin_headers[$i], 8, 1);
+
         translate([0, 60])
             box_header(pin_headers[$i], 10, 2);
 
+        translate([0, 70])
+            pin_socket(pin_headers[$i], 8, 1);
+
         translate([0, 80])
             pin_socket(pin_headers[$i], 10, 2);
 
-        translate([0, 110])
-            pin_socket(pin_headers[$i], 10, 2, right_angle = true);
+        translate([-10, 105])
+            pin_socket(pin_headers[$i], 3, 1, right_angle = true);
 
+        translate([0, 105])
+            pin_socket(pin_headers[$i], 3, 2, right_angle = true);
+
+        translate([10, 105])
+            pin_socket(pin_headers[$i], 3, 3, right_angle = true);
     }
 
+    for(i = [0, 1], p = [5, 2][i], j = [0 , 1]) {
+        h = [jst_ph_header, jst_xh_header][j];
+        translate([-20 * (i + 1), 0 + j * 40])
+            jst_xh_header(h, p);
+
+        translate([-20 * (i + 1), 20 + j * 40])
+            jst_xh_header(h, p, true);
+    }
+}
+
 if($preview)
     pin_headers();

tests/printed_box.scad

@@ -67,7 +67,7 @@ module box1_external_additions() {
 
 module box1_holes() {
     box1_feet_positions()
-        teardrop(r = screw_pilot_hole(foot_screw(foot)), h = 10, center = true);
+        teardrop_plus(r = screw_pilot_hole(foot_screw(foot)), h = 10, center = true);
 }
 
 

tests/rails.scad

@@ -25,10 +25,10 @@ use <../vitamins/nut.scad>
 sheet = 3;
 
 module rails()
-    layout([for(l = rails) carriage_width(rail_carriage(l))], 25)
+    layout([for(l = rails) carriage_width(rail_carriage(l))], 20)
         rotate(-90) {
             rail = rails[$i];
-            length = rail == MGN15 ? 260 : 200;
+            length = 200;
             screw = rail_screw(rail);
             nut = screw_nut(screw);
             washer = screw_washer(screw);

tests/ribbon_clamp.scad

@@ -16,20 +16,22 @@
 // You should have received a copy of the GNU General Public License along with NopSCADlib.
 // If not, see <https://www.gnu.org/licenses/>.
 //
-include <../utils/core/core.scad>
+include <../core.scad>
 use <../printed/ribbon_clamp.scad>
 use <../vitamins/wire.scad>
 
-ways = 20;
+ways = [8, 20];
+screws = [M2_dome_screw, M3_cap_screw];
 
 module ribbon_clamps()
-    translate([ribbon_clamp_length(ways) / 2, 0])
-        if($preview) {
-            ribbon_clamp_fastened_assembly(ways, 3);
+    for(i = [0 : len(screws) - 1])
+        translate([ribbon_clamp_length(ways[i]) / 2, i * 30])
+            if($preview) {
+                ribbon_clamp_fastened_assembly(ways[i], 3, screws[i]);
 
-            ribbon_cable(ways, 100);
-        }
-        else
-            ribbon_clamp(ways);
+                ribbon_cable(ways[i], 100);
+            }
+            else
+                ribbon_clamp(ways[i], screws[i]);
 
 ribbon_clamps();

tests/shaft_couplings.scad

@@ -0,0 +1,30 @@
+//
+// NopSCADlib Copyright Chris Palmer 2018
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../core.scad>
+include <../vitamins/shaft_couplings.scad>
+
+use <../utils/layout.scad>
+
+module shaft_couplings()
+    layout([for(s = shaft_couplings) sc_diameter(s)],5)
+        shaft_coupling(shaft_couplings[$i]);
+
+if($preview)
+    shaft_couplings();
+

tests/stepper_motors.scad

@@ -22,12 +22,12 @@ include <../vitamins/stepper_motors.scad>
 use <../utils/layout.scad>
 
 module stepper_motors()
-    layout([for(s = stepper_motors) NEMA_width(s)], 5) {
+    layout([for(s = stepper_motors) NEMA_width(s)], 5) let(m = stepper_motors[$i]) {
         rotate(180)
-            NEMA(stepper_motors[$i]);
+            NEMA(m, 0, m == NEMA17M || m == NEMA17M8);
 
         translate_z(4)
-            NEMA_screws(stepper_motors[$i], M3_pan_screw, n = $i, earth = $i > 4 ? undef : $i - 1);
+            NEMA_screws(m, M3_pan_screw, n = $i, earth = $i > 4 ? undef : $i - 1);
     }
 
 if($preview)

tests/teardrops.scad

@@ -41,7 +41,10 @@ module teardrops() {
 
                         translate([20, 10])
                             semi_teardrop(h = 0, r = 3);
-                    }
+
+                        translate([20, 20])
+                            teardrop(h = 0, r = 3, truncate = false, plus = true);
+                   }
                 }
                 translate([40, 0, 1.5]) {
                     h = 3 + eps;
@@ -61,6 +64,9 @@ module teardrops() {
 
                     translate([20, 10])
                         semi_teardrop(h = h, r = 3, chamfer = chamfer);
+
+                    translate([20, 20])
+                        teardrop(h = h, r = 3, truncate = false, plus = false, chamfer = chamfer);
                 }
             }
 }

tests/thread.scad

@@ -26,27 +26,27 @@ profile = thread_profile(pitch / 2, pitch * 0.366, 30);
 
 module threads()
     for(female = [false, true]) translate([0, female ? -20 : 0]) {
-    length = female ? 8  : 40;
-    dia = female ? 8 : 8 - pitch;
-    colour = female ? brass : silver;
+        length = female ? 8  : 40;
+        dia = female ? 8 : 8 - pitch;
+        colour = female ? brass : silver;
 
-    thread(dia, starts * pitch, length, profile, starts = starts, top = 45, bot = 45, female = female, colour = colour);
+        thread(dia, starts * pitch, length, profile, starts = starts, top = 45, bot = 45, female = female, colour = colour);
 
-    color(colour)
-        translate([20, 0])
-            thread(dia, starts * pitch, length, profile, starts = starts, top = 0, bot = 0, female = female);
+        color(colour)
+            translate([20, 0])
+                thread(dia, starts * pitch, length, profile, starts = starts, top = 0, bot = 0, female = female);
 
-    translate([40, 0])
-        thread(dia, starts * pitch, length, profile, starts = starts, top = -1, bot = -1, female = female, colour = colour);
+        translate([40, 0])
+            thread(dia, starts * pitch, length, profile, starts = starts, top = -1, bot = -1, female = female, colour = colour);
 
-    color(colour)
-        translate([60, 0])
-            thread(dia, 2 * pitch, length, profile, starts = 2, top = -1, bot = -1, female = female);
+        color(colour)
+            translate([60, 0])
+                thread(dia, 2 * pitch, length, profile, starts = 2, top = -1, bot = -1, female = female);
 
-    color(colour)
-        translate([80, 0])
-            thread(dia, pitch, length, profile, starts = 1, top = -1, bot = -1, female = female);
-}
+        color(colour)
+            translate([80, 0])
+                thread(dia, pitch, length, profile, starts = 1, top = -1, bot = -1, female = female);
+    }
 
 let($show_threads = true)
     threads();

tests/tubings.scad

@@ -22,7 +22,7 @@ use <../utils/layout.scad>
 include <../vitamins/tubings.scad>
 
 module tubings()
-    layout([for(t = tubings) tubing_od(t)], 10)
+    layout([for(t = tubings) tubing_od(t)], 8)
         tubing(tubings[$i]);
 
 if($preview)

utils/catenary.scad

@@ -0,0 +1,52 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Catenary curve to model hanging wires, etc.
+//!
+//! Although the equation of the curve is simply ```y = a cosh(x / a)``` there is no explicit formula to calculate the constant ```a``` or the range of ```x``` given the
+//! length of the cable and the end point coordinates. See <https://en.wikipedia.org/wiki/Catenary#Determining_parameters>. The Newton-Raphson method is used to find
+//! ```a``` numerically, see <https://en.wikipedia.org/wiki/Newton%27s_method>.
+//!
+//! The coordinates of the lowest point on the curve can be retrieved by calling ```catenary_points()``` with ```steps``` equal to zero.
+//
+include <core/core.scad>
+use <maths.scad>
+
+function catenary(t, a) = let(u = argsinh(t)) a * [u, cosh(u)]; //! Parametric catenary function linear along the length of the curve.
+function catenary_s(d, a) = 2 * a * sinh(d / a); //! Length of a symmetric catenary with width ```2d```.
+function catenary_ds_by_da(d, a) = 2 * sinh(d / a) - 2 * d / a * cosh(d / a); //! First derivative of the length with respect to ```a```.
+
+function catenary_find_a(d, l, a = 1, best_e = inf, best_a = 1) =  //! Find the catenary constant ```a```, given half the horizontal span and the length.
+     assert(l > 2 * d, "Not long enough to span the gap") assert(d) let(error = abs(catenary_s(d, a) - l))
+     error >= best_e && error < 0.0001 ? best_a
+                                       : catenary_find_a(d, l, max(a - (catenary_s(d, a) - l) / catenary_ds_by_da(d, a), d / argsinh(1e99)), error, a);
+
+function catenary_points(l, x, y, steps = 100) = //! Returns a list of 2D points on the curve that goes from the origin to ```(x,y)``` and has length ```l```.
+    let(
+        d = x / 2,
+        a = catenary_find_a(d, sqrt(sqr(l) - sqr(y))),   // Find a to get the correct length
+        offset = argsinh(y / catenary_s(d, a)),
+        t0 = sinh(-d / a + offset),
+        t1 = sinh( d / a + offset),
+        h = a * cosh(-d / a + offset) - a,
+        lowest = offset > d / a ? [0, 0] : offset < -d / a ? [x, y] : [d - offset * a, -h],
+        p0 = catenary(t0, a)
+    )
+    steps ? [for(t = [t0 : (t1 - t0) / steps : t1]) catenary(t, a) - p0] : lowest;

utils/core/core.scad

@@ -18,7 +18,7 @@
 //
 
 //
-// Include this file to use the miniumum library
+// Include this file to use the minimum library
 //
 include <../../global_defs.scad>
 //
@@ -28,12 +28,12 @@ use <global.scad>
 
 module use_stl(name) {               //! Import an STL to make a build platter
     stl(name);
-
-    import(str("../stls/", name, ".stl"));
+    path = is_undef($target) ? "../stls/" : str("../", $target, "/stls/");
+    import(str(path, name, ".stl"));
 }
 
 module use_dxf(name) {               //! Import a DXF to make a build panel
     dxf(name);
-
-    import(str("../dxfs/", name, ".dxf"));
+    path = is_undef($target) ? "../dxfs/" : str("../", $target, "/dxfs/");
+    import(str(path, name, ".dxf"));
 }

utils/core/global.scad

@@ -31,16 +31,27 @@ function m(x)    = x * 1000.0;
 
 function sqr(x) = x * x;                                                            //! Returns the square of ```x```
 function echoit(x) = echo(x) x;                                                     //! Echo expression and return it, useful for debugging
+function no_point(str) = chr([for(c = str(str)) if(c == ".") ord("p") else ord(c)]);//! Replace decimal point in string with 'p'
 function in(list, x) = !!len([for(v = list) if(v == x) true]);                      //! Returns true if ```x``` is an element in the ```list```
 function Len(x) = is_list(x) ? len(x) : 0;                                          //! Returns the length of a list or 0 if ```x``` is not a list
 function r2sides(r) = $fn ? $fn : ceil(max(min(360/ $fa, r * 2 * PI / $fs), 5));    //! Replicates the OpenSCAD logic to calculate the number of sides from the radius
 function r2sides4n(r) = floor((r2sides(r) + 3) / 4) * 4;                            //! Round up the number of sides to a multiple of 4 to ensure points land on all axes
+function limit(x, min, max) = max(min(x, max), min);                                //! Force x in range min <= x <= max
 
 module translate_z(z) translate([0, 0, z]) children();                              //! Shortcut for Z only translations
-module vflip() rotate([180, 0, 0]) children();                                      //! Invert children by doing a 180&deg; flip around the X axis
-module hflip() rotate([0, 180, 0]) children();                                      //! Invert children by doing a 180&deg; flip around the Y axis
+module vflip(flip=true) rotate([flip ? 180 : 0, 0, 0]) children();                  //! Invert children by doing a 180&deg; flip around the X axis
+module hflip(flip=true) rotate([0, flip ? 180: 0, 0]) children();                   //! Invert children by doing a 180&deg; flip around the Y axis
 module ellipse(xr, yr) scale([1, yr / xr]) circle4n(xr);                            //! Draw an ellipse
 
+function slice_str(str, start, end, s ="") = start >= end ? s : slice_str(str, start + 1, end, str(s, str[start])); // Helper for slice()
+
+function slice(list, start = 0, end = undef) = let( //! Slice a list or string with Python type semantics
+        len = len(list),
+        start = limit(start < 0 ? len + start : start, 0, len),
+        end   = is_undef(end) ? len : limit(end   < 0 ? len + end : end, 0, len)
+    ) is_string(list) ? slice_str(list, start, end) : [for(i = [start : 1 : end - 1]) list[i]];
+
+
 module extrude_if(h, center = true)                 //! Extrudes 2D object to 3D when ```h``` is nonzero, otherwise leaves it 2D
     if(h)
         linear_extrude(h, center = center, convexity = 2) // 3D

utils/core/polyholes.scad

@@ -32,10 +32,14 @@ module poly_circle(r, sides = 0) { //! Make a circle adjusted to print the corre
     circle(r = corrected_radius(r,n), $fn = n);
 }
 
-module poly_cylinder(r, h, center = false, sides = 0) //! Make a cylinder adjusted to print the correct size
+module poly_cylinder(r, h, center = false, sides = 0, chamfer = false) {//! Make a cylinder adjusted to print the correct size
     extrude_if(h, center)
         poly_circle(r, sides);
 
+    if(h && chamfer)
+        poly_cylinder(r + layer_height, center ? layer_height * 2 : layer_height, center, sides = sides ? sides : sides(r));
+}
+
 module poly_ring(or, ir, sides = 0) { //! Make a 2D ring adjusted to have the correct internal radius
     cir = corrected_radius(ir, sides);
     filaments = (or - cir) / extrusion_width;

utils/core/teardrops.scad

@@ -20,17 +20,32 @@
 //
 //! For making horizontal holes that don't need support material.
 //! Small holes can get away without it, but they print better with truncated teardrops.
+//!
+//! Using teardrop_plus() or setting the plus option on other modules will elongate the teardrop vertically by the layer height, so when sliced the staircase tips
+//! do not intrude into the circle. See <https://hydraraptor.blogspot.com/2020/07/horiholes-2.html>
 //
-module teardrop(h, r, center = true, truncate = true, chamfer = 0) { //! For making horizontal holes that don't need support material, set ```truncate = false``` to make traditional RepRap teardrops that don't even need bridging
+module teardrop(h, r, center = true, truncate = true, chamfer = 0, plus = false) { //! For making horizontal holes that don't need support material, set ```truncate = false``` to make traditional RepRap teardrops that don't even need bridging
     module teardrop_2d(r, truncate) {
-        hull() {
-            circle4n(r);
-            if(truncate)
-                translate([0, r / 2])
-                    square([2 * r * (sqrt(2) - 1), r], center = true);
-            else
-                polygon([[0, 0], [eps, 0], [0, r * sqrt(2)]]);
-        }
+        er = layer_height / 2 - eps;    // Extrustion edge radius
+        R = plus ? r + er : r;          // Corrected radius
+        offset = plus ? -er : 0;        // Offset inwards
+        hull()
+            for(side = [0 : 1])
+                mirror([side, 0, 0])
+                    intersection() {
+                        hull()
+                        translate([offset, 0]) {
+                            circle4n(R);
+
+                            if(truncate)
+                                translate([0, R / 2])
+                                    square([2 * R * (sqrt(2) - 1), R], center = true);
+                            else
+                                polygon([[0, 0], [eps, 0], [0, R * sqrt(2)]]);
+                        }
+                        translate([0, -2 * R])
+                            square([R, 4 * R]);
+                    }
     }
 
     render(convexity = 5)
@@ -40,23 +55,23 @@ module teardrop(h, r, center = true, truncate = true, chamfer = 0) { //! For mak
     teardrop_chamfer(h, center, chamfer) {
         linear_extrude(eps, center = true)
             teardrop_2d(r + chamfer / 2, truncate);
+
         translate_z(-chamfer / 2)
             linear_extrude(eps, center = true)
                 teardrop_2d(r, truncate);
     }
 }
 
-module semi_teardrop(h, r, d = undef, center = true, chamfer = 0) { //! A semi teardrop in the positive Y domain
-    module semi_teardrop_2d(r, d) {
+module semi_teardrop(h, r, d = undef, center = true, chamfer = 0, plus = false) { //! A semi teardrop in the positive Y domain
+    module semi_teardrop_2d(r, d)
         intersection() {
             R = is_undef(d) ? r : d / 2;
-            teardrop(r = R, h = 0);
+            teardrop(r = R, h = 0, plus = plus);
 
             sq = R + 1;
             translate([-sq, 0])
                 square([2 * sq, sq]);
         }
-    }
 
     render(convexity = 5)
         extrude_if(h, center)
@@ -65,22 +80,21 @@ module semi_teardrop(h, r, d = undef, center = true, chamfer = 0) { //! A semi t
     teardrop_chamfer(h, center, chamfer) {
         linear_extrude(eps, center = true)
             semi_teardrop_2d(r + chamfer / 2, d);
+
         translate_z(-chamfer / 2)
             linear_extrude(eps, center = true)
                 semi_teardrop_2d(r, d);
     }
 }
 
-module teardrop_plus(h, r, center = true, truncate = true, chamfer = 0) //! Slightly bigger teardrop to allow for the 3D printing staircase effect
-    teardrop(h, r + layer_height / 4, center, truncate, chamfer);
+module teardrop_plus(h, r, center = true, truncate = true, chamfer = 0) //! Slightly elongated teardrop to allow for the 3D printing staircase effect
+    teardrop(h, r, center, truncate, chamfer, plus = true);
 
-module tearslot(h, r, w, center = true, chamfer = 0) { //! A horizontal slot that doesn't need support material
-    module tearslot_2d(r, w) {
-        hull() {
-            translate([-w / 2, 0]) teardrop(r = r, h = 0);
-            translate([w / 2, 0]) teardrop(r = r, h = 0);
-        }
-    }
+module tearslot(h, r, w, center = true, chamfer = 0, plus = false) { //! A horizontal slot that doesn't need support material
+    module tearslot_2d(r, w)
+        hull()
+            for(x = [-1, 1])
+                translate([x * w / 2, 0]) teardrop(r = r, h = 0, plus = plus);
 
     extrude_if(h, center)
         tearslot_2d(r, w);
@@ -88,19 +102,19 @@ module tearslot(h, r, w, center = true, chamfer = 0) { //! A horizontal slot tha
     teardrop_chamfer(h, center, chamfer) {
         linear_extrude(eps, center = true)
             tearslot_2d(r + chamfer / 2, w);
+
         translate_z(-chamfer / 2)
             linear_extrude(eps, center = true)
                 tearslot_2d(r, w);
     }
 }
 
-module vertical_tearslot(h, r, l, center = true, chamfer = 0) { //! A vertical slot that doesn't need support material
-    module vertical_tearslot_2d(r, l) {
-        hull() {
-            translate([0,  l / 2]) teardrop(0, r, true);
-            translate([0, -l / 2]) circle4n(r);
-        }
-    }
+module vertical_tearslot(h, r, l, center = true, chamfer = 0, plus = false) { //! A vertical slot that doesn't need support material
+    module vertical_tearslot_2d(r, l)
+        hull()
+            for(y = [-1, 1])
+                translate([0,  y * l / 2])
+                    teardrop(0, r, true, plus = plus);
 
     extrude_if(h, center)
         vertical_tearslot_2d(r, l);
@@ -108,6 +122,7 @@ module vertical_tearslot(h, r, l, center = true, chamfer = 0) { //! A vertical s
     teardrop_chamfer(h, center, chamfer) {
         linear_extrude(eps, center = true)
             vertical_tearslot_2d(r + chamfer / 2, l);
+
         translate_z(-chamfer / 2)
             linear_extrude(eps, center = true)
                 vertical_tearslot_2d(r, l);
@@ -123,4 +138,3 @@ module teardrop_chamfer(h, center, chamfer) { //! Helper module for adding chamf
                         hull()
                             children();
 }
-

utils/gears.scad

@@ -0,0 +1,138 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Utilities for making involute gears.
+//!
+//! Formulas from <https://khkgears.net/new/gear_knowledge/gear_technical_reference/involute_gear_profile.html>
+//! <https://khkgears.net/new/gear_knowledge/gear_technical_reference/calculation_gear_dimensions.html>
+//! and <https://www.tec-science.com/mechanical-power-transmission/involute-gear/calculation-of-involute-gears/>
+//!
+//! ```involute_gear_profile()``` returns a polygon that can have the bore and spokes, etc, subtracted from it before linear extruding it to 3D.
+//! Helical gears can be made using ```twist``` and bevel gears using ```scale``` parameters of ```linear_extrude()```.
+//!
+//! Gears with less than 19 teeth (when pressure angle is 20) are profile shifted to avoid undercutting the tooth root. 7 teeth is considered
+//! the practical minimum.
+//!
+//! The clearance between tip and root defaults to module / 6, but can be overridden by setting the ```clearance``` parameter.
+//!
+//! The origin of the rack is the left end of the pitch line and its width is below the pitch line. I.e. it does not include the addendum.
+//!
+//! ```involute_worm_profile()``` returns a tooth profile that can be passed to ```thread()``` to make worms.
+//
+include <core/core.scad>
+use <maths.scad>
+
+function involute(r, u) = let(a = degrees(u), c = cos(a), s = sin(a)) r * [c + u * s, s - u * c]; //! Involute of circle radius r at angle u in radians
+
+function profile_shift(z, pa) = z ? max(1 - z * sqr(sin(pa)) / 2, 0) : 0; //! Calculate profile shift for small gears
+
+function centre_distance(m, z1, z2, pa = 20) = //! Calculate distance between centres taking profile shift into account
+    let(x1 = profile_shift(z1, pa), x2 = profile_shift(z2, pa)) m * (z1/2 + z2/2 + x1 + x2);
+
+function involute_gear_od(m, z, pa = 20) = //! involute gear outside diameter given modulus, tooth count and pressure angle
+    m * (z + 2 * profile_shift(z, pa) + 2);
+
+module involute_gear_profile(m, z, pa = 20, clearance = undef, steps = 20) { //! Calculate gear profile given module, number of teeth and pressure angle
+    assert(z >= 7, "Gears must have at least 7 teeth.");
+    d = m * z;                                                  // Reference pitch circle diameter
+    x = profile_shift(z, pa);                                   // Profile shift
+    c = is_undef(clearance) ? m / 6 : clearance;                // Clearance from tip to root
+
+    base_d = d * cos(pa);                                       // Base diameter
+    root_r = d / 2 + m * (x - 1) - c;                           // Root radius (dedendum circle radius)
+    tip_d = d + 2 * m * (1 + x);                                // Tip diameter (addendum circle diameter)
+    tpa = acos(base_d / tip_d);                                 // Tip pressure angle
+    inva = tan(pa) - radians(pa);                               // Involute alpha
+    invaa = tan(tpa) - radians(tpa);                            // Involute alphaa
+    ta =  PI / (2 * z) + 2 * x * tan(pa) / z + inva - invaa;    // Tooth tip thickness angle, radians
+    crest_w = ta * tip_d;                                       // Crest width
+    umax = sqrt(sqr(tip_d / base_d) - 1);                       // Max value of the involute parameter
+
+    base_r = base_d / 2;
+    p1 = involute(base_r, 0);
+    p2 = involute(base_r, umax);
+    dist = norm(p2 - p1);                                       // distance between beginning and end of the involute curve
+
+    base_angle = 2 * acos((sqr(base_r) + sqr(tip_d / 2) - sqr(dist)) / base_r / tip_d) + degrees(2 * ta);
+    root_angle = 360 / z - base_angle;
+    root_circle_r = base_r * sin(root_angle / 2);
+
+    if(!is_undef($show_numbers) && $show_numbers) {
+        echo(d=d);
+        echo(base_d=base_d);
+        echo(tip_d=tip_d);
+        echo(tpa = tpa);
+        echo(inva=inva);
+        echo(invaa=invaa);
+        echo(x=x);
+        echo(ta=ta);
+        echo(crest_w=crest_w);
+        echo(umax = umax);
+        echo(base_angle=base_angle);
+        echo(root_angle=root_angle);
+    }
+    involute = [for(i = [0 : steps], u = umax * i / steps) involute(base_r, u)]; // involute for the bottom side of the tooth
+    truncated = [for(p = involute) if((rot2_z(-base_angle / 2) * p).y <= 0) p];  // removed any above the centreline to prevent overlap
+    reflection = reverse([for(p = truncated) rot2_z(base_angle) * [p.x, -p.y] ]); // reflect and rotate to make the top edge
+
+    root = reverse([for(a = [90 : 180 / steps : 270]) rot2_z(base_angle + root_angle / 2) * ([base_r, 0] + root_circle_r * [cos(a), sin(a)]) ]);
+    tooth = concat(truncated, reflection, root);
+    gear = concat([for(i = [0 : z - 1], p = tooth) rot2_z(i * 360 / z) * p]);
+    rotate(-base_angle / 2)
+        union() {
+            polygon(gear);
+
+            circle(root_r);
+        }
+}
+
+function involute_rack_tooth_profile(m, pa = 20, clearance = undef) = //! Calculate rack tooth profile given module and pressure angle
+    let(p = PI * m,                                     // Pitch
+        ha = m,                                         // Addendum
+        c = is_undef(clearance) ? m / 4 : clearance,    // Tip root clearance
+        hf = m + c,                                     // Dedendum
+        hw = 2 * m,                                     // Working depth
+        h = ha + hf,                                    // Tooth depth
+        crest_w = p / 2 - 2 * ha * tan(pa),             // Crest width
+        base_w = crest_w + 2 * hw * tan(pa),            // Base width
+        root_w = p - base_w,                            // Root width
+        clearance_w = root_w - 2 * c * tan(pa),         // Width of clearance without fillet
+        kx = tan(pa / 2 + 45),                          // Fillet ratio of radius and xoffset
+        pf = min(0.38 * m, kx * clearance_w / 2),       // Dedendum fillet radius
+        x = pf / kx,                                    // Fillet centre x offset from corner
+        sides = ceil(r2sides(pf) * (90 - pa) / 360),    // Fillet facets taking $fa, $fs and $fn into account
+        fillet = [ for(i = [0 : sides - 1], a = i * (90 - pa) / sides + 270) [clearance_w / 2 - x,  -hf + pf] + pf * [cos(a), sin(a)] ],
+        reflection = reverse([for(pt = fillet) [p - pt.x, pt.y] ]) // reflect for trailing edge
+    ) concat(fillet, [ [root_w / 2, -hw / 2], [p / 2 - crest_w / 2, ha], [p / 2 + crest_w / 2, ha], [p - root_w / 2, -hw / 2] ], reflection);
+
+module involute_rack_profile(m, z, w, pa = 20, clearance = undef) { //! Calculate rack profile given module, number of teeth and pressure angle
+    p = PI * m;                                     // Pitch
+    hf = 1.25 * m;                                  // Dedendum
+    tooth = involute_rack_tooth_profile(m, pa, clearance);
+    teeth = [for(i = [0 : z - 1], pt = tooth) [pt.x + i * p, pt.y] ];
+
+    polygon(concat([[0, -w], [0, -hf]], teeth, [[z * p, -hf ], [z * p, -w]])); // Add the corners
+}
+
+function involute_worm_profile(m, pa = 20, clearance = undef) = //! Calculate worm profile suitable for passing to thread()
+    let(tooth = involute_rack_tooth_profile(m),
+        pitch = PI * m,
+        y_min = min([for(p = tooth) p.y])
+    ) [for(p = tooth) [p.x - pitch / 2, p.y - y_min, 0]];   // Offset to be positive in y, centred in x and add 0 z ordintate

utils/hanging_hole.scad

@@ -39,11 +39,13 @@ module hanging_hole(z, ir, h = 100, h2 = 100) { //! Hole radius ```ir``` hanging
     infill_angle = z % (2 * layer_height) ? -45 : 45;
     below = min(z + eps, h2);
     big = 1000;
-
     render(convexity = 3) translate_z(z)
         union() {
             translate_z(2 * layer_height)
-                polyhole(ir - eps, h - 2 * layer_height);
+                if(sides(ir) > 4)
+                    polyhole(ir - eps, h - 2 * layer_height);
+                else
+                    poly_cylinder(ir, h - 2 * layer_height);
 
             difference() {
                 translate_z(-below)

utils/horiholes.scad

@@ -0,0 +1,83 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Utilities for depicting the staircase slicing of horizontal holes made with [`teardrop_plus()`](#teardrops), see <https://hydraraptor.blogspot.com/2020/07/horiholes-2.html>
+//!
+//! ```horicylinder()``` makes cylinders that fit inside a round hole. Layers that are less than 2 filaments wide and layers that need more than a 45 degree overhang are omitted.
+//
+include <../utils/core/core.scad>
+
+function teardrop_plus_x(r, y, h) = //! Calculate the ordinate of a compensated teardrop given y and layer height.
+    let(fr = h / 2,
+        hpot = r + fr,
+        x2 = sqr(hpot) - sqr(y),
+        x = x2 > 0 ? sqrt(x2) : 0
+    )
+    max(0,
+        y < hpot / sqrt(2) ? x - fr :
+        y < hpot           ? hpot * sqrt(2) - y - fr :
+        0);
+
+module horihole(r, z, h = 0, center = true) { //! For making horizontal holes that don't need support material and are correct dimensions
+    bot_layer = floor((z - r) / layer_height);
+    top_layer = ceil((z + r) / layer_height);
+    render(convexity = 5)
+        extrude_if(h, center)
+            for(i = [bot_layer : top_layer]) {
+                Z = i * layer_height;
+                y = Z - z + layer_height / 2;
+                x = teardrop_plus_x(r, y, layer_height);
+                if(x > 0)
+                    translate([0, y])
+                        difference() {
+                            square([2 * x + layer_height, layer_height], center = true);
+
+                            for(end = [-1, 1])
+                                translate([end * (x + layer_height / 2), 0])
+                                    circle(d = layer_height, $fn = 32);
+                        }
+             }
+}
+
+function teardrop_minus_x(r, y, h) = //! Calculate the ordinate of a compensated teardrop given y and layer height.
+    let(fr = h / 2,
+        hpot = r - fr,
+        x2 = sqr(hpot) - sqr(y),
+        x = x2 > 0 ? sqrt(x2) : 0,
+        X = y >= -hpot / sqrt(2) ? x + fr : 0
+    )
+    X >= extrusion_width ? X : 0;
+
+module horicylinder(r, z, h = 0, center = true) { //! For making horizontal cylinders that don't need support material and are correct dimensions
+    bot_layer = floor((z - r) / layer_height);
+    top_layer = ceil((z + r) / layer_height);
+    render(convexity = 5)
+        extrude_if(h, center)
+            for(i = [bot_layer : top_layer]) {
+                Z = i * layer_height;
+                y = Z - z + layer_height / 2;
+                x = teardrop_minus_x(r, y, layer_height);
+                if(x >= extrusion_width)
+                    hull()
+                        for(end = [-1, 1])
+                            translate([end * (x - layer_height / 2), y])
+                                circle(d = layer_height, $fn = 32);
+             }
+}

utils/layout.scad

@@ -28,6 +28,6 @@ function layout_offset(widths, i, gap = 2) = //! Calculate the offset for the ``
 
 module layout(widths, gap = 2, no_offset = false) //! Layout children passing ```$i```
     translate([no_offset ? -widths[0] / 2 : 0, 0])
-        for($i = [0 : len(widths) - 1])
+        for($i = [0 : 1 : len(widths) - 1])
             translate([layout_offset(widths, $i, gap), 0])
                 children();

utils/maths.scad

@@ -20,7 +20,18 @@
 //
 //! Maths utilities for manipulating vectors and matrices.
 //
-function sqr(x) = x * x;
+function sqr(x) = x * x;                        //! Square x
+function radians(degrees) = degrees * PI / 180; //! Convert radians to degrees
+function degrees(radians) = radians * 180 / PI; //! Convert degrees to radians
+
+function sinh(x) = (exp(x) - exp(-x)) / 2;      //! hyperbolic sine
+function cosh(x) = (exp(x) + exp(-x)) / 2;      //! hyperbolic cosine
+function tanh(x) = sinh(x) / cosh(x);           //! hyperbolic tangent
+function coth(x) = cosh(x) / sinh(x);           //! hyperbolic cotangent
+function argsinh(x) = ln(x + sqrt(sqr(x) + 1)); //! inverse hyperbolic sine
+function argcosh(x) = ln(x + sqrt(sqr(x) - 1)); //! inverse hyperbolic cosine
+function argtanh(x) = ln((1 + x) / (1 - x)) / 2;//! inverse hyperbolic tangent
+function argcoth(x) = ln((x + 1) / (x - 1)) / 2;//! inverse hyperbolic cotangent
 
 function translate(v) = let(u = is_list(v) ? len(v) == 2 ? [v.x, v.y, 0] //! Generate a 4x4 translation matrix, ```v``` can be ```[x, y]```, ```[x, y, z]``` or ```z```
                                                          : v
@@ -63,6 +74,12 @@ function rot3_z(a) = //! Generate a 3x3 matrix to rotate around z
           [ s,  c,  0],
           [ 0,  0,  1] ];
 
+function rot2_z(a) = //! Generate a 2x2 matrix to rotate around z
+    let(c = cos(a),
+        s = sin(a))
+        [ [ c, -s],
+          [ s,  c] ];
+
 function scale(v) = let(s = is_list(v) ? v : [v, v, v]) //!  Generate a 4x4 matrix that scales by ```v```, which can be a vector of xyz factors or a scalar to scale all axes equally
                         [
                           [s.x, 0,   0,   0],
@@ -90,3 +107,49 @@ function euler(R) = let(ay = asin(-R[2][0]), cy = cos(ay)) //! Convert a rotatio
     cy ? [ atan2(R[2][1] / cy, R[2][2] / cy), ay, atan2(R[1][0] / cy, R[0][0] / cy) ]
        : R[2][0] < 0 ? [atan2( R[0][1],  R[0][2]),  180, 0]
                      : [atan2(-R[0][1], -R[0][2]), -180, 0];
+
+module position_children(list, t) //! Position children if they are on the Z = 0 plane when transformed by t
+    for(p = list)
+        let(q = t * p)
+            if(abs(transform([0, 0, 0], q).z) < 0.01)
+                multmatrix(q)
+                    children();
+
+// Matrix inversion: https://www.mathsisfun.com/algebra/matrix-inverse-row-operations-gauss-jordan.html
+
+function augment(m) = let(l = len(m), n = identity(l)) [ //! Augment a matrix by adding an identity matrix to the right
+    for(i = [0 : l - 1])
+        concat(m[i], n[i])
+];
+
+function rowswap(m, i, j) = [ //! Swap two rows of a matrix
+    for(k = [0 : len(m) - 1])
+        k == i ? m[j] : k == j ? m[i] : m[k]
+];
+
+function solve_row(m, i) = let(diag = m[i][i]) [ //! Make diagonal one by dividing the row by it and subtract from other rows to make column zero
+    for(j = [0 : len(m) - 1])
+        i == j ? m[j] / diag : m[j] - m[i] * m[j][i] / diag
+];
+
+function nearly_zero(x) = abs(x) < 1e-5; //! True if x is close to zero
+
+function solve(m, i = 0, j = 0) = //! Solve each row ensuring diagonal is not zero
+    i < len(m) ?
+        assert(i + j < len(m), "matrix is singular")
+         solve(!nearly_zero(m[i + j][i]) ? solve_row(j ? rowswap(m, i, i + j) : m, i) : solve(m, i, j + 1), i + 1)
+        : m;
+
+function invert(m) = let(n =len(m), m = solve(augment(m))) [ //! Invert a matrix
+    for(i = [0 : n - 1]) [
+        for(j = [n : 2 * n - 1])
+             each m[i][j]
+    ]
+];
+
+function circle_intersect(c1, r1, c2, r2) =     //! Calculate one point where two circles in the X-Z plane intersect, clockwise around c1
+    let(
+        v = c1 - c2,                            // Line between centres
+        d = norm(v),                            // Distance between centres
+        a = atan2(v.z, v.x) - acos((sqr(d) + sqr(r2) - sqr(r1)) / (2 * d * r2)) // Cosine rule to find angle from c2
+     ) c2 + r2 * [cos(a), 0, sin(a)];           // Point on second circle

utils/quadrant.scad

@@ -23,18 +23,21 @@
 include <../utils/core/core.scad>
 
 module quadrant(w, r, center = false) { //! Draw a square with one rounded corner, can be centered on the arc centre, when ```center``` is ```true```.
-    offset = center ? r - w : 0;
-    translate([offset, offset])
+    h = is_list(w) ? w.y : w;
+    w = is_list(w) ? w.x : w;
+    offset_w = center ? r - w : 0;
+    offset_h = center ? r - h : 0;
+    translate([offset_w, offset_h])
         hull() {
             intersection() {
-                translate([w - r, w - r])
+                translate([w - r, h - r])
                     circle4n(r);
 
-                square(w);
+                square([w, h]);
             }
 
             square([w, eps]);
 
-            square([eps, w]);
+            square([eps, h]);
         }
 }

utils/sweep.scad

@@ -34,14 +34,22 @@ function transpose3(m) = [ [m[0].x, m[1].x, m[2].x],
                            [m[0].y, m[1].y, m[2].y],
                            [m[0].z, m[1].z, m[2].z] ];
 //
+// Find the first non-colinear point
+//
+tiny = 0.00001;
+function find_curve(tangents, i = 1) =
+    i >= len(tangents) - 1 || norm(cross(tangents[0], tangents[i] - tangents[0])) > tiny ? i
+                                                                                         : find_curve(tangents, i + 1);
+//
 // Frenet-Serret frame
 //
 function fs_frame(tangents) =
     let(tangent = tangents[0],
-        normal = tangents[1] - tangents[0],
+        i = find_curve(tangents),
+        normal = tangents[i] - tangents[0],
         binormal = cross(tangent, normal),
         z = unit(tangent),
-        x = assert(norm(binormal) > 0.00001, "first three points are colinear") unit(binormal),
+        x = assert(norm(binormal) > tiny, "all points are colinear") unit(binormal),
         y = unit(cross(z, x))
        ) [[x.x, y.x, z.x],
           [x.y, y.y, z.y],
@@ -70,7 +78,6 @@ function orientate(p, r) =
          [x.y, y.y, z.y],
          [x.z, y.z, z.z],
          [p.x, p.y, p.z]];
-
 //
 // Rotate around z
 //
@@ -145,10 +152,10 @@ function sweep(path, profile, loop = false, twist = 0) = //! Generate the point
         faces = loop ? skin_faces : concat([cap(facets)], skin_faces, [cap(facets, npoints - 1)])
         ) [points, faces];
 
-module sweep(path, profile, loop = false, twist = 0) { //! Draw a polyhedron that is the swept volume
+module sweep(path, profile, loop = false, twist = 0, convexity = 1) { //! Draw a polyhedron that is the swept volume
     mesh = sweep(path, profile, loop, twist);
 
-    polyhedron(points = mesh[0], faces = mesh[1]);
+    polyhedron(points = mesh[0], faces = mesh[1], convexity = convexity);
 }
 
 function path_length(path, i = 0, length = 0) = //! Calculated the length along a path

utils/thread.scad

@@ -26,6 +26,8 @@
 //! Threads are by default solid, so the male version is wrapped around a cylinder and the female inside a tube. This can be suppressed to just get the helix, for
 //! example to make a printed pot with a screw top lid.
 //!
+//! A left hand thread can be made by using mirror([0,1]).
+//!
 //! Threads with a typical 60 degree angle appear too bright with OpenSCAD's primitive lighting model as they face towards the lights more than the top and sides of
 //! a cylinder. To get around this a colour can be passed to thread that is used to colour the cylinder and then toned down to colour the helix.
 //!
@@ -47,7 +49,7 @@ function thread_profile(h, crest, angle, overlap = 0.1) = //! Create thread prof
     let(base = crest + 2 * (h + overlap) * tan(angle / 2))
         [[-base / 2, -overlap, 0], [-crest / 2, h, 0], [crest / 2, h, 0], [base / 2, -overlap, 0]];
 
-module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, starts = 1, solid = true, female = false, colour = undef) { //! Create male or femail thread, ends can be tapered, chamfered or square
+module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, starts = 1, solid = true, female = false, colour = undef) { //! Create male or female thread, ends can be tapered, chamfered or square
     //
     // Apply colour if defined
     //
@@ -61,10 +63,12 @@ module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, st
     // Extract some properties from the profile, perhaps they should be stored in it.
     //
     h = max([for(p = sprofile) p.y]);
-    maxx = max([for(p = sprofile) p.x]);
-    minx = min([for(p = sprofile) p.x]);
-    crest_xmax = max([for(p = sprofile) if(p.x != maxx) p.x]);
-    crest_xmin = min([for(p = sprofile) if(p.x != minx) p.x]);
+    xs = [for(p = sprofile) p.x];
+    maxx = max(xs);
+    minx = min(xs);
+    crest_xs = [for(p = sprofile) if(p.y == h) p.x];
+    crest_xmax = max(crest_xs);
+    crest_xmin = min(crest_xs);
     //
     // If the ends don't taper we need an extra half turn past the ends to be cropped horizontally.
     //
@@ -129,11 +133,13 @@ module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, st
                     render() intersection() {
                         polyhedron(points, ends_faces);
 
-                        len = length - 2 * eps;
+                        shorten = !is_undef(colour);
+                        len = shorten ? length - 2 * eps : length;
+                        offset = shorten ? eps : 0;
                         rotate_extrude()
                             if(female) {
                                 difference() {
-                                    translate([0, eps])
+                                    translate([0, offset])
                                         square([r + h + overlap, len]);
 
                                     if(top_chamfer_h)
@@ -146,7 +152,7 @@ module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, st
                             else
                                 difference() {
                                     hull() {
-                                        translate([0, eps])
+                                        translate([0, offset])
                                             square([r, len]);
 
                                         translate([0, bot_chamfer_h])

utils/tube.scad

@@ -31,3 +31,41 @@ module ring(or, ir) //! Create a ring with specified external and internal radii
 module tube(or, ir, h, center = true) //! Create a tube with specified external and internal radii and height ```h```
     linear_extrude(h, center = center, convexity = 5)
         ring(or, ir);
+
+module woven_tube(or, ir, h, center= true, colour = grey(30), colour2, warp = 2, weft) {//! Create a woven tube with specified external and internal radii, height ```h```, colours, warp and weft
+    colour2 = colour2 ? colour2 : colour * 0.8;
+    weft = weft ? weft : warp;
+    warp_count = max(floor(PI * or / warp), 0.5);
+    angle = 360 / (2 * warp_count);
+
+    module layer(weft) {
+        points = [[ir, weft / 2], [or, weft / 2], [or, -weft / 2], [ir, -weft / 2]];
+        color(colour)
+            for (i = [0 : warp_count])
+                rotate(2 * i * angle)
+                    rotate_extrude(angle = angle)
+                        polygon(points);
+        color(colour2)
+            for (i = [0 : warp_count])
+                rotate((2 * i + 1) * angle)
+                    rotate_extrude(angle = angle)
+                        polygon(points);
+    }
+
+    translate_z(center ? -h / 2 : 0) {
+        weft_count = floor(h / weft);
+        if (weft_count > 0)
+            for (i = [0 : weft_count - 1]) {
+                translate_z(i * weft + weft / 2)
+                    rotate(i * angle)
+                        layer(weft);
+        }
+        remainder = h - weft * weft_count;
+        if (remainder) {
+            translate_z(weft_count * weft + remainder / 2)
+                rotate(weft_count * angle)
+                    layer(remainder);
+        }
+    }
+}
+

vitamins/axial.scad

@@ -24,6 +24,7 @@ include <../utils/core/core.scad>
 include <../utils/round.scad>
 
 module wire_link(d, l, h = 1, tail = 3) { //! Draw a wire jumper link.
+    vitamin(str("wire_link(", d, ", ", l, arg(h, 1, "h"), arg(tail, 3, "tail"),  "): Wire link ", d, "mm x ", l / inch(1), "\""));
     r = d;
     $fn = 32;
 
@@ -57,13 +58,16 @@ module orientate_axial(length, height, pitch, wire_d) { // Orient horizontal or
     min_pitch = ceil((length + 1) / inch(0.1)) * inch(0.1);
     lead_pitch = pitch ? pitch : min_pitch;
     if(lead_pitch >= min_pitch) {
-        wire_link(wire_d, lead_pitch, height);
+        not_on_bom()
+            wire_link(wire_d, lead_pitch, height);
+
         translate_z(height)
             rotate([0, 90, 0])
                 children();
     }
     else {
-        wire_link(wire_d, lead_pitch, length + 0.7 + wire_d);
+        not_on_bom()
+            wire_link(wire_d, lead_pitch, length + 0.7 + wire_d);
 
         translate([-pitch / 2, 0, length / 2 + 0.2])
             children();

vitamins/ball_bearing.scad

@@ -52,21 +52,21 @@ module ball_bearing(type) { //! Draw a ball bearing
         rim_chamfer = rim / 6;
         rotate_extrude()
             hull() {
-                translate([or - rim / 2, 0])
-                    square([rim, h - 2 * rim_chamfer], center = true);
+                translate([or - rim, -h / 2 + rim_chamfer])
+                    square([rim, h - 2 * rim_chamfer]);
 
-                translate([or - rim / 2 - rim_chamfer, 0])
-                    square([rim - rim_chamfer, h], center = true);
+                translate([or - rim, -h / 2])
+                    square([rim - rim_chamfer, h]);
             }
 
         hub_chamfer = hub / 6;
         rotate_extrude()
             hull() {
-                translate([ir + hub / 2, 0])
-                    square([hub, h - 2 * hub_chamfer], center = true);
+                translate([ir, -h / 2 + hub_chamfer])
+                    square([hub, h - 2 * hub_chamfer]);
 
-                translate([ir + hub / 2 + hub_chamfer, 0])
-                    square([hub - hub_chamfer, h], center = true);
+                translate([ir + hub_chamfer, -h / 2])
+                    square([hub - hub_chamfer, h]);
             }
     }
 

vitamins/ball_bearings.scad

@@ -16,11 +16,12 @@
 // You should have received a copy of the GNU General Public License along with NopSCADlib.
 // If not, see <https://www.gnu.org/licenses/>.
 //
-BB624 =  ["624",  4,  13, 5, "blue",      1.2, 1.2];  // 624 ball bearing for idlers
-BB608 =  ["608",  8,  22, 7, "OrangeRed", 1.4, 2.0];  // 608 bearings for wades
-BB6200 = ["6200", 10, 30, 9, "black",     2.3, 3.6];  // 6200 bearings for KP pillow blocks
-BB6201 = ["6201", 12, 32, 10, "black",    2.4, 3.7];  // 6201 bearings for KP pillow blocks
-BB6808 = ["6808", 40, 52, 7, "black",     1.5, 1.6];
-ball_bearings = [BB624, BB608, BB6200, BB6201, BB6808];
+BBSMR95 =  ["SMR95", 5,  9,  2.5, "silver",    0.5, 0.7];  // SMR95 ball bearing for FlexDrive extruder
+BB624   =  ["624",   4,  13, 5,   "blue",      1.2, 1.2];  // 624 ball bearing for idlers
+BB608   =  ["608",   8,  22, 7,   "OrangeRed", 1.4, 2.0];  // 608 bearings for wades
+BB6200   = ["6200",  10, 30, 9,   "black",     2.3, 3.6];  // 6200 bearings for KP pillow blocks
+BB6201   = ["6201",  12, 32, 10,  "black",     2.4, 3.7];  // 6201 bearings for KP pillow blocks
+BB6808   = ["6808",  40, 52, 7,   "black",     1.5, 1.6];
+ball_bearings = [BBSMR95, BB624, BB608, BB6200, BB6201, BB6808];
 
 use <ball_bearing.scad>

vitamins/belt.scad

@@ -19,61 +19,67 @@
 
 //
 //! Models timing belt running over toothed or smooth pulleys and calculates an accurate length.
-//! Only models 2D paths, so not core XY!
+//! Only models 2D paths, so not crossed belt core XY!
 //!
 //! To make the back of the belt run against a smooth pulley on the outside of the loop specify a negative pitch radius.
 //!
 //! By default the path is a closed loop but a gap length and position can be specified to make open loops.
+//! To draw the gap its XY position is specified by ```gap_pos```. ```gap_pos.z``` can be used to specify a rotation if the gap is not at the bottom of the loop.
 //!
 //! Individual teeth are not drawn, instead they are represented by a lighter colour.
 //
 include <../utils/core/core.scad>
 use <../utils/rounded_polygon.scad>
+use <../utils/maths.scad>
 
 function belt_pitch(type)        = type[1]; //! Pitch in mm
 function belt_width(type)        = type[2]; //! Width in mm
 function belt_thickness(type)    = type[3]; //! Total thickness including teeth
 function belt_tooth_height(type) = type[4]; //! Tooth height
-function belt_pitch_height(type) = belt_tooth_height(type) + type[4]; //! Offset of the pitch radius from the tips of the teeth
+function belt_pitch_height(type) = type[5] + belt_tooth_height(type); //! Offset of the pitch radius from the tips of the teeth
 
-function no_point(str) = chr([for(c = str) if(c == ".") ord("p") else ord(c)]);
+function belt_pitch_to_back(type) = belt_thickness(type) - belt_pitch_height(type); //! Offset of the back from the pitch radius
 //
 // We model the belt path at the pitch radius of the pulleys and the pitch line of the belt to get an accurate length.
 // The belt is then drawn by offseting each side from the pitch line.
 //
-module belt(type, points, gap = 0, gap_pt = undef, belt_colour = grey(20), tooth_colour = grey(50)) { //! Draw a belt path given a set of points and pitch radii where the pulleys are. Closed loop unless a gap is specified
+module belt(type, points, gap = 0, gap_pos = undef, belt_colour = grey(20), tooth_colour = grey(50)) { //! Draw a belt path given a set of points and pitch radii where the pulleys are. Closed loop unless a gap is specified
     width = belt_width(type);
     pitch = belt_pitch(type);
     thickness = belt_thickness(type);
     part = str(type[0],pitch);
-    vitamin(str("belt(", no_point(part), "x", width, ", ", points, arg(gap, 0), arg(gap_pt, undef), "): Belt ", part," x ", width, "mm x ", length, "mm"));
+    vitamin(str("belt(", no_point(part), "x", width, ", ", points, arg(gap, 0), arg(gap_pos, undef), "): Belt ", part," x ", width, "mm x ", length, "mm"));
 
     len = len(points);
 
     tangents = rounded_polygon_tangents(points);
 
-    length = ceil((rounded_polygon_length(points, tangents) - gap) / pitch) * pitch;
+    length = ceil((rounded_polygon_length(points, tangents) - (is_list(gap) ? gap.x + gap.y : gap)) / pitch) * pitch;
 
     module shape() rounded_polygon(points, tangents);
 
+    ph = belt_pitch_height(type);
+    th = belt_tooth_height(type);
     module gap()
         if(gap)
-            translate(gap_pt)
-                square([gap, thickness + eps], center = true);
+            translate([gap_pos.x, gap_pos.y])
+                rotate(is_undef(gap_pos.z) ? 0 : gap_pos.z)
+                    translate([0, ph - thickness / 2])
+                        square(is_list(gap) ? [gap.x, gap.y + thickness + eps] : [gap, thickness + eps], center = true);
 
     color(belt_colour)
         linear_extrude(width, center = true)
             difference() {
-                offset(thickness - belt_pitch_height(type)) shape();
-                offset(-belt_pitch_height(type) + belt_tooth_height(type)) shape();
+                offset(-ph + thickness ) shape();
+                offset(-ph + th) shape();
                 gap();
-
             }
+
     color(tooth_colour)
         linear_extrude(width, center = true)
             difference() {
-                offset(-belt_pitch_height(type) + belt_tooth_height(type)) shape();
-                offset(-belt_pitch_height(type)) shape();
+                offset(-ph + th) shape();
+                offset(-ph) shape();
                 gap();
             }
 }

vitamins/blower.scad

@@ -22,6 +22,8 @@
 //
 include <../utils/core/core.scad>
 use <../utils/rounded_cylinder.scad>
+use <../utils/quadrant.scad>
+use <screw.scad>
 
 function blower_length(type)      = type[2]; //! Length of enclosing rectangle
 function blower_width(type)       = type[3]; //! Width of enclosing rectangle
@@ -39,8 +41,87 @@ function blower_top(type)         = type[14]; //! Thickness of the top
 function blower_wall(type)        = type[15]; //! Side wall thickness
 function blower_lug(type)         = type[16]; //! Height of the lugs
 
+function blower_casing_is_square(type) = len(blower_screw_holes(type)) > 3; //! True for square radial fans, false for spiral shape radial blowers
+function blower_exit_offset(type) = blower_casing_is_square(type) ? blower_length(type) / 2 : blower_exit(type) / 2; //! Offset of exit's centre from the edge
+
 fan_colour = grey(20);
 
+module blower_fan(type, casing_is_square) {
+    module squarish(s, n) {
+        polygon([
+            for(i = [0 : n]) [i * s.x / n,  s.y + (i % 2) * eps],
+            for(i = [0 : n]) [s.x - i * s.x / n, (i % 2) * eps],
+        ]);
+    }
+
+    depth = blower_depth(type);
+    blade_ir = blower_hub(type) / 2 + 0.5; // slight gap between main part of blades and hub
+    blade_len = casing_is_square
+        ? (blower_bore(type) - 1) / 2 - blade_ir // fan constrained by bore hole
+        : blower_width(type) - blower_axis(type).x- blower_wall(type) - blade_ir; // fan extends to casing
+    blade_thickness = 0.75;
+    blade_count = 25;
+
+    base_offset = 1;
+    translate([blower_axis(type).x, blower_axis(type).y, blower_base(type) + base_offset])
+        linear_extrude(blower_hub_height(type) - 0.5 - blower_base(type) - base_offset, center = false, convexity = 4, twist = -30, slices = round(depth / 2))
+            for(i = [0 : blade_count - 1])
+                rotate((360 * i) / blade_count)
+                    translate([blade_ir, -blade_thickness / 2])
+                        squarish([blade_len, blade_thickness], round(blade_len / 2));
+}
+
+module blower_square(type) { //! Draw a square blower
+    width = blower_width(type);
+    depth = blower_depth(type);
+    wall = blower_wall(type);
+    hole_pitch = (blower_screw_holes(type)[1].x - blower_screw_holes(type)[0].x) / 2;
+    corner_radius = width / 2 - hole_pitch;
+    corner_inset = (width - blower_exit(type)) / 2;
+
+    module square_inset_corners(remove_center = false)
+        difference() {
+            //overall outside
+                square([width, width], center = false);
+
+            if (remove_center) {
+                // cut out the inside, leaving the corners
+                translate([corner_inset + wall, -eps])
+                    square([width - 2 * (wall + corner_inset), width - wall + eps], center = false);
+
+                translate([wall, corner_inset + wall])
+                    square([width - 2 * wall, width - 2 * (wall + corner_inset)], center = false);
+            } else {
+                // cut out the bore for the fan
+                translate(blower_axis(type))
+                    circle(d = blower_bore(type));
+            }
+            // corner inset
+            translate([width / 2, width / 2])
+            for(i = [0 : 3])
+                rotate(i * 90)
+                    translate([-width / 2 - eps, -width/ 2 - eps])
+                        quadrant(corner_inset, corner_inset - corner_radius);
+        }
+
+    base_height = blower_base(type);
+    linear_extrude(base_height)
+        difference () {
+            rounded_square([width, width], corner_radius, center = false);
+
+            blower_hole_positions(type)
+                circle(d = blower_screw_hole(type));
+        }
+
+    translate_z(base_height)
+        linear_extrude(depth - base_height)
+            square_inset_corners(remove_center = true);
+
+    translate_z(depth - base_height)
+        linear_extrude(blower_top(type))
+            square_inset_corners();
+}
+
 module blower(type) { //! Draw specified blower
     length = blower_length(type);
     width = blower_width(type);
@@ -70,55 +151,63 @@ module blower(type) { //! Draw specified blower
 
     vitamin(str("blower(", type[0], "): ", type[1]));
 
+    is_square = blower_casing_is_square(type); // Description starts with square!
     color(fan_colour) {
-        // screw lugs
-        linear_extrude(blower_lug(type), center = false)
-            for(hole = blower_screw_holes(type))
-                difference() {
-                    hull() {
+        if (is_square) {
+            blower_square(type);
+        } else {
+            // screw lugs
+            linear_extrude(blower_lug(type), center = false)
+                for(hole = blower_screw_holes(type))
+                    difference() {
+                        hull() {
+                            translate(hole)
+                                circle(d = blower_screw_hole(type) + 2 * blower_wall(type));
+
+                            translate(blower_axis(type))
+                                circle(d = blower_screw_hole(type) + 2 * blower_wall(type) + 7);
+                        }
                         translate(hole)
-                            circle(d = blower_screw_hole(type) + 2 * blower_wall(type));
+                            circle(d = blower_screw_hole(type));
 
-                        translate(blower_axis(type))
-                            circle(d = blower_screw_hole(type) + 2 * blower_wall(type) + 7);
-                    }
-                    translate(hole)
-                        circle(d = blower_screw_hole(type));
+                        shape(true);
+                }
 
-                    shape(true);
-               }
-        // rotor
-        translate(concat(blower_axis(type), [blower_base(type) + 1]))
-            rounded_cylinder(r = blower_hub(type) / 2, h = blower_hub_height(type) - blower_base(type) - 1, r2 = 1);
+            *%square([length, width]);
 
-        *%square([length, width]);
-
-        // base
-        linear_extrude(blower_base(type))
-            difference() {
-                shape();
-
-                translate(concat(blower_axis(type), [blower_base(type)]))
-                    circle(d = 2);
-           }
-        // sides
-        linear_extrude(depth)
-            difference() {
-                shape();
-
-                offset(-blower_wall(type))
-                    shape(true);
-           }
-
-        // top
-        translate_z(depth -blower_top(type))
-            linear_extrude(blower_top(type))
+            // base
+            linear_extrude(blower_base(type))
                 difference() {
                     shape();
 
                     translate(concat(blower_axis(type), [blower_base(type)]))
-                        circle(d = blower_bore(type));
-               }
+                        circle(d = 2);
+            }
+
+            // sides
+            linear_extrude(depth)
+                difference() {
+                    shape();
+
+                    offset(-blower_wall(type))
+                        shape(true);
+            }
+
+            // top
+            translate_z(depth -blower_top(type))
+                linear_extrude(blower_top(type))
+                    difference() {
+                        shape();
+
+                        translate(concat(blower_axis(type), [blower_base(type)]))
+                            circle(d = blower_bore(type));
+                }
+        }
+        // rotor
+        translate(concat(blower_axis(type), [blower_base(type) + 1]))
+            rounded_cylinder(r = blower_hub(type) / 2, h = blower_hub_height(type) - blower_base(type) - 1, r2 = 1);
+
+        blower_fan(type, is_square);
     }
 }