screw_polysink now has an alternating layer option to be more printable inverted.

The screws test now tests polysinks and has printable sample.

global_defs.scad

@@ -35,8 +35,8 @@ extrusion_width = is_undef($extrusion_width) ? 0.5    : $extrusion_width; // fil
 nozzle          = is_undef($nozzle)          ? 0.45   : $nozzle;          // 3D printer nozzle
 cnc_bit_r       = is_undef($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" : $pp3_colour;      // printed part colour 3
+pp2_colour      = is_undef($pp2_colour)      ? "Crimson"  : $pp2_colour;  // printed part colour 2
+pp3_colour      = is_undef($pp3_colour)      ? "SteelBlue" : $pp3_colour; // printed part colour 3
 pp4_colour      = is_undef($pp4_colour)      ? "darkorange" : $pp4_colour;// printed part colour 4
 show_rays       = is_undef($show_rays)       ? false  : $show_rays;       // show camera sight lines and light direction
 show_threads    = is_undef($show_threads)    ? false  : $show_threads;    // show screw threads

libtest.scad

@@ -52,6 +52,7 @@ 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>
@@ -77,6 +78,7 @@ use <tests/opengrab.scad>
 use <tests/panel_meters.scad>
 use <tests/PCBs.scad>
 use <tests/pillars.scad>
+use <tests/press_fit.scad>
 use <tests/PSUs.scad>
 use <tests/pulleys.scad>
 use <tests/rails.scad>
@@ -136,9 +138,12 @@ cable_grommets_y = 0;
 translate([x5, cable_grommets_y])
     cable_grommets();
 
-translate([x5 + 80, cable_grommets_y])
+translate([x5 + 50, cable_grommets_y])
     ribbon_clamps();
 
+translate([x5 + 95, cable_grommets_y])
+    press_fits();
+
 translate([x5, cable_grommets_y + 60])
     fixing_blocks();
 
@@ -417,12 +422,16 @@ translate([x4 + 200, belts_y + 58]) {
 
     translate([0, 60])
         opengrab_test();
+
 }
 
+translate([x4 + 175, belts_y, -20])
+    drag_chains();
+
 translate([x4, rails_y + 130])
     rails();
 
-translate([800, fans_y + 50])
+translate([770, fans_y + 50])
     cable_strips();
 
 translate([x4, kp_pillow_blocks_y])

printed/box.scad

@@ -121,11 +121,12 @@ module grill(width, height, r = 1000, poly = false, h = 0) { //! A staggered arr
 
 module box_corner_profile_2D(type) { //! The 2D shape of the corner profile.
     t = box_sheet_slot(type);
+    inset = box_corner_gap(type) + box_profile_overlap(type);
     difference() {
         union() {
             quadrant(box_hole_inset(type) + box_boss_r(type), box_boss_r(type));     // inside corner
 
-            translate([box_corner_gap(type) + box_profile_overlap(type), box_corner_gap(type) + box_profile_overlap(type)])
+            translate([inset, inset])
                 rotate(180)
                     quadrant(box_profile_overlap(type) + box_corner_rad(type), box_corner_rad(type)); // outside corner
         }
@@ -212,33 +213,39 @@ module box_bezel(type, bottom) { //! Generates top and bottom bezel STLs
     feet = bottom && box_feet(type);
     t = box_sheet_slot(type);
     outset =  box_outset(type);
+    inset = box_inset(type);
     inner_r = box_sheet_r(type);
-    foot_height = box_corner_gap(type) + sheet_thickness(box_base_sheet(type)) + washer_thickness(box_washer(type)) + screw_head_height(box_screw(type)) + box_profile_overlap(type) + 2;
+    cgap = box_corner_gap(type);
+    foot_height = cgap + sheet_thickness(box_base_sheet(type)) + washer_thickness(box_washer(type)) + screw_head_height(box_screw(type)) + box_profile_overlap(type) + 2;
     foot_length = box_corner_rad(type) * 2;
     height = box_bezel_height(type, bottom);
     foot_extension = foot_height - height;
 
     difference() {
+        w = box_width(type);
+        d = box_depth(type);
         translate_z(-box_profile_overlap(type)) difference() {
-            rounded_rectangle([box_width(type) + 2 * outset, box_depth(type) + 2 * outset, feet ? foot_height : height], box_corner_rad(type), false);
+            tw = w + 2 * outset;
+            td = d + 2 * outset;
+            rounded_rectangle([tw, td, feet ? foot_height : height], box_corner_rad(type), false);
             //
             // Remove edges between the feet
             //
             if(feet)
                 hull() {
                     translate_z(height + 0.5)
-                        cube([box_width(type) - 2 * foot_length, box_depth(type) + 2 * outset + 1, 1], center = true);
+                        cube([w - 2 * foot_length, td + 1, 1], center = true);
 
                     translate_z(foot_height + 1)
-                        cube([box_width(type) - 2 * (foot_length - foot_extension), box_depth(type) + 2 * outset + 1, 1], center = true);
+                        cube([w - 2 * (foot_length - foot_extension), td + 1, 1], center = true);
                 }
             if(feet)
                 hull() {
                     translate_z(height + 0.5)
-                        cube([box_width(type) + 2 * outset + 1, box_depth(type) - 2 * foot_length, 1], center = true);
+                        cube([tw + 1, d - 2 * foot_length, 1], center = true);
 
                     translate_z(foot_height + 1)
-                        cube([box_width(type) + 2 * outset + 1, box_depth(type) - 2 * (foot_length - foot_extension), 1], center = true);
+                        cube([tw + 1, d - 2 * (foot_length - foot_extension), 1], center = true);
                 }
         }
         //
@@ -247,28 +254,28 @@ module box_bezel(type, bottom) { //! Generates top and bottom bezel STLs
         translate_z(-box_profile_overlap(type))
             linear_extrude(2 * box_profile_overlap(type), center = true)
                 for(i = [-1, 1]) {
-                    translate([i * (box_width(type) / 2 + t / 2 - sheet_slot_clearance / 2), 0])
-                         square([t, box_depth(type) - 2 * box_corner_gap(type)], center = true);
+                    translate([i * (w + t - sheet_slot_clearance) / 2, 0])
+                         square([t, d - 2 * cgap], center = true);
 
-                    translate([0, i * (box_depth(type) / 2 + t / 2 - sheet_slot_clearance / 2)])
-                         square([box_width(type) - 2 * box_corner_gap(type), t], center = true);
+                    translate([0, i * (d + t - sheet_slot_clearance) / 2])
+                         square([w - 2 * cgap, t], center = true);
                 }
         //
         // recess for top / bottom panel
         //
-        translate_z(box_corner_gap(type))
-            rounded_rectangle([box_width(type) + bezel_clearance, box_depth(type) + bezel_clearance, height], inner_r + bezel_clearance / 2, false);
+        translate_z(cgap)
+            rounded_rectangle([w + bezel_clearance, d + bezel_clearance, height], inner_r + bezel_clearance / 2, false);
         //
         // leave plastic over the corner profiles
         //
         translate_z(-box_profile_overlap(type) - 1)
-            linear_extrude(box_profile_overlap(type) + box_corner_gap(type) + 2)
+            linear_extrude(box_profile_overlap(type) + cgap + 2)
                 union() {
                     difference() {
-                        square([box_width(type) - 2 * box_inset(type),
-                                box_depth(type) - 2 * box_inset(type)], center = true);
+                        square([w - 2 * inset,
+                                d - 2 * inset], center = true);
 
-                        box_corner_quadrants(type, box_width(type), box_depth(type));
+                        box_corner_quadrants(type, w, d);
                     }
                     box_screw_hole_positions(type)
                         poly_circle(screw_clearance_radius(box_screw(type)));
@@ -291,7 +298,9 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
     dw = bw - 2 * dowel_wall;
     dh = box_bezel_height(type, bottom) - dowel_h_wall;
 
-    dh2 = box_profile_overlap(type) + box_corner_gap(type) - dowel_h_wall;
+    profile_overlap = box_profile_overlap(type);
+
+    dh2 = profile_overlap + box_corner_gap(type) - dowel_h_wall;
 
     end_clearance = 0.5;
     module male() {
@@ -299,14 +308,14 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
             linear_extrude(dowel_length - 2 * end_clearance, center = true)
                 difference() {
                     union() {
-                        h = dh - layer_height;
+                        h1 = dh - layer_height;
                         h2 = dh2 - layer_height;
                         hull() {
-                            translate([bw / 2, h / 2])
-                                square([dw - 1, h], center = true);
+                            translate([bw / 2, h1 / 2])
+                                square([dw - 1, h1], center = true);
 
-                            translate([bw / 2, (h - 1) / 2])
-                                square([dw, h - 1], center = true);
+                            translate([bw / 2, (h1 - 1) / 2])
+                                square([dw, h1 - 1], center = true);
                         }
 
                         hull() {
@@ -318,7 +327,7 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
                         }
                     }
                     translate([bw2 / 2, 0])
-                        square([box_sheet_slot(type), 2 * box_profile_overlap(type)], center = true);
+                        square([box_sheet_slot(type), 2 * profile_overlap], center = true);
                 }
     }
 
@@ -359,7 +368,7 @@ 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([tw / 2 - x * w, th / 2 - y * h, box_profile_overlap(type)])
+                    translate([tw / 2 - x * w, th / 2 - y * h, profile_overlap])
                         box_bezel(type, bottom);
 
                 if(x < cols - 1 && y == 0)
@@ -419,10 +428,14 @@ module box_bezel_section(type, bottom, rows, cols, x, y) { //! Generates interlo
     }
 }
 
-module box_screw_hole_positions(type)
+module box_screw_hole_positions(type) {
+    inset = box_hole_inset(type);
+    w = box_width(type) / 2 - inset;
+    d = box_depth(type) / 2 - inset;
     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))])
+        translate([x * w, y * d])
             children();
+}
 
 module box_base_blank(type) { //! Generates a 2D template for the base sheet
     dxf("box_base");

printed/drag_chain.scad

@@ -22,13 +22,21 @@
 //!
 //! Each link has a maximum bend angle of 45°, so the mininium radius is proportional to the link length.
 //!
-//! The travel prpoery 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.
+//! 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.
+//!
+//! The ends can have screw lugs with four screw positions to choose from, specified by a list of two arrays of four bools.
+//! If none are enabled then a child object is expected to customise the end and this gets unioned with the blank end.
+//! If both ends are customised then two children are expected.
+//! Each child is called twice, once with ```$fasteners``` set to 0 to augment the STL and again with ```$fasteners``` set to 1 to add
+//! to the assembly, for example to add inserts.
 //
 
 include <../core.scad>
 use <../utils/horiholes.scad>
 use <../utils/maths.scad>
 
+clearance = 0.1;
+
 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
@@ -38,6 +46,8 @@ 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_clearance() = clearance; //! Clearance around joints.
+
 function drag_chain_radius(type) = //! The bend radius at the pivot centres
     let(s = drag_chain_size(type))
         s.x / 2 / sin(360 / 16);
@@ -49,13 +59,11 @@ function drag_chain_z(type) = //! Outside dimension of a 180 bend
 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
+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
+function screw_lug_radius(screw) = //! Radius of 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
@@ -73,23 +81,18 @@ module screw_lug(screw, h = 0) //! Create a D shaped lug for a 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
+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);
+    for(i = [0 : 3], x = [x0, x1, x0, x1][i], y = [-1, -1, 1, 1][i])
         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();
-    }
+            translate([x, y * (s.y / 2 + r)])
+                let($a = [180, 0, 180, 0][i])
+                    children();
 }
 
 function drag_chain_cam_x(type) = // how far the cam sticks out
@@ -100,8 +103,7 @@ function drag_chain_cam_x(type) = // how far the cam sticks out
         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
+module drag_chain_link(type, start = false, end = false, check_kids = true) { //! 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);
@@ -210,14 +212,23 @@ module drag_chain_link(type, start = false, end = false) { //! One link of the c
             translate([floor_x, -os.y / 2 + 0.5,  os.z - bwall])
                 cube([s.x - floor_x - clearance, os.y -1, bwall]);
 
-            if(start || end)
+            if(start || end) {
                 drag_chain_screw_positions(type, end)
-                    screw_lug(drag_chain_screw(type), os.z);
+                    rotate($a)
+                        screw_lug(drag_chain_screw(type), os.z);
+
+                if(check_kids) {
+                    custom = drag_chain_screw_lists(type)[bool2int(end)] == [0, 0, 0, 0];
+                    assert($children == bool2int(custom), str("wrong number of children for ",  end ? "end" : "start", " STL customisation: ", $children));
+                }
+                children();
+            }
         }
         if(start || end)
             translate_z(-eps)
                 drag_chain_screw_positions(type, end)
-                    poly_cylinder(r = screw_clearance_radius(drag_chain_screw(type)), h = os.z + 2 * eps, center = false);
+                    rotate($a)
+                        poly_cylinder(r = screw_clearance_radius(drag_chain_screw(type)), h = os.z + 2 * eps, center = false);
 
     }
 
@@ -239,11 +250,11 @@ module drag_chain_link(type, start = false, end = false) { //! One link of the c
     }
 }
 
-//! 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
+// Need to use a wrapper because can't define nested modules in an assembly
+module _drag_chain_assembly(type, pos = 0) {
     s = drag_chain_size(type);
-    r = drag_chain_radius(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;
@@ -255,31 +266,56 @@ module drag_chain_assembly(type, pos = 0) { //! Drag chain assembly
     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 ? s.x : -s.x,
+            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, s.x, c, r))
-                        q.x <= c.x ? [p.x - sqrt(sqr(s.x) - sqr(p.z - zb)), 0, zb] // Transition back to straight
+                  : 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 % 2 ? pp1_colour : pp2_colour)
-                drag_chain_link(type, start = n == -1, end = n == npoints - 1);
+        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, check_kids = false)
+                    let($fasteners = 0) children();
+            let($fasteners = 1) children();
+        }
 
-    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);
+    screws = drag_chain_screw_lists(type);
+    custom_start = screws[0] == [0, 0, 0, 0];
+    custom_end   = screws[1] == [0, 0, 0, 0];
+    assert($children == bool2int(custom_start) + bool2int(custom_end), str("wrong number of children for end customisation: ", $children));
 
-        translate(points[0] - [s.x, 0, 0])
-            link(-1);
+    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[npoints - 1])
-            hflip()
-                link(npoints - 1);
-    }
+    translate(points[0] - [x, 0, 0])
+        link(-1)
+            if(custom_start)
+                children(0);
+
+    translate(points[npoints - 1])
+        hflip()
+            link(npoints - 1)
+                if(custom_end)
+                    children(custom_start ? 1 : 0);
 }
+
+//! 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
+    assembly(str(drag_chain_name(type), "_drag_chain"), big = true)
+        if($children == 2)
+            _drag_chain_assembly(type, pos) {
+                children(0);
+                children(1);
+            }
+        else if($children == 1)
+            _drag_chain_assembly(type, pos)
+                children(0);
+        else
+            _drag_chain_assembly(type, pos);

printed/press_fit.scad

@@ -0,0 +1,50 @@
+//
+// 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/>.
+//
+
+//
+//! Utility for making printed press fit connectors to join printed parts.
+//!
+//! Add solvent or glue to make a permanent fixture.
+//
+include <../core.scad>
+
+interference = 0.0;
+
+bridge_droop = layer_height; //sqrt(4 * layer_height * filament_width / PI) - layer_height;
+
+module press_fit_socket(w = 5, h = 50, horizontal = false) { //! Make a square hole to accept a peg
+    h = horizontal ? h : h + bridge_droop;
+
+    cube([w, w, 2 * h], center = true);
+}
+
+module press_fit_peg(h, w = 5, horizontal = false) {    //! Make a rounded chamfered peg for easy insertion
+    module chamfered_square(w, horizontal) {
+        h = horizontal ? w - bridge_droop : w;
+        rounded_square([w, h], 1);
+    }
+
+    translate_z(-eps)
+        linear_extrude(height = h + eps - layer_height)
+            chamfered_square(w + interference, horizontal);
+
+    translate_z(h - layer_height - eps)
+        linear_extrude(height = layer_height + eps)
+            chamfered_square(w - layer_height, horizontal);
+}

printed/ribbon_clamp.scad

@@ -81,7 +81,7 @@ module ribbon_clamp(ways, screw = screw) { //! Generate STL for given number of
     }
 }
 
-module ribbon_clamp_assembly(ways, screw) pose([55, 180, 25])  //! Printed part with inserts in place
+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);

readme.md

@@ -36,13 +36,13 @@ See [usage](docs/usage.md) for requirements, installation instructions and a usa
 <tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#Nuts">Nuts</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#Handle">Handle</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
 <tr><td> <a href = "#Extrusion_brackets">Extrusion_brackets</a> </td><td> <a href = "#O_ring">O_ring</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#PCB_mount">PCB_mount</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
 <tr><td> <a href = "#Extrusions">Extrusions</a> </td><td> <a href = "#Opengrab">Opengrab</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td> <a href = "#PSU_shroud">PSU_shroud</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
-<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
-<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
-<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
-<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Panel_meters">Panel_meters</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Pillars">Pillars</a> </td><td> <a href = "#Variacs">Variacs</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Pin_headers">Pin_headers</a> </td><td> <a href = "#Veroboard">Veroboard</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#IECs">IECs</a> </td><td> <a href = "#Pulleys">Pulleys</a> </td><td> <a href = "#Washers">Washers</a> </td><td></td><td></td><td></td></tr>
+<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#Press_fit">Press_fit</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
+<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
+<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
+<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Panel_meters">Panel_meters</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Pillars">Pillars</a> </td><td> <a href = "#Variacs">Variacs</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Pin_headers">Pin_headers</a> </td><td> <a href = "#Veroboard">Veroboard</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#IECs">IECs</a> </td><td> <a href = "#Pulleys">Pulleys</a> </td><td> <a href = "#Washers">Washers</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
 <tr><td> <a href = "#Inserts">Inserts</a> </td><td></td><td> <a href = "#Wire">Wire</a> </td><td></td><td></td><td></td></tr>
 <tr><td></td><td></td><td> <a href = "#Zipties">Zipties</a> </td><td></td><td></td><td></td></tr>
 </table>
@@ -474,8 +474,8 @@ PCB cameras.
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| ```camera(type)``` | Draw specified PCB camera |
-| ```camera_lens(type, offset = 0)``` | Draw the lens stack, with optional offset for making a clearance hole |
+| ```camera(type, show_lens = true)``` | Draw specified PCB camera |
+| ```camera_lens(type, offset = 0, show_lens = true)``` | Draw the lens stack, with optional offset for making a clearance hole |
 
 ![cameras](tests/png/cameras.png)
 
@@ -2707,6 +2707,7 @@ Linear rails with carriages.
 | Function | Description |
 |:--- |:--- |
 | ```carriage_screw_depth(type)``` | Carriage thread depth |
+| ```rail_holes(type, length)``` | Number of holes in a rail given its ```length``` |
 | ```rail_screw_height(type, screw)``` | Position screw taking into account countersink into counterbored hole |
 | ```rail_travel(type, length)``` | How far the carriage can travel |
 
@@ -2903,6 +2904,8 @@ These items are sysmtrical, so by default the origin is in the centre but it can
 ## Screws
 Machine screws and wood screws with various head styles.
 
+For an explanation of ```screw_polysink()``` see <https://hydraraptor.blogspot.com/2020/12/sinkholes.html>.
+
 
 [vitamins/screws.scad](vitamins/screws.scad) Object definitions.
 
@@ -2929,9 +2932,10 @@ Machine screws and wood screws with various head styles.
 | Function | Description |
 |:--- |:--- |
 | ```screw_boss_diameter(type)``` | Boss big enough for nut trap and washer |
-| ```screw_head_depth(type, d)``` | How far a counter sink head will go into a straight hole diameter d |
+| ```screw_head_depth(type, d = 0)``` | How far a counter sink head will go into a straight hole diameter d |
 | ```screw_longer_than(x)``` | Returns shortest screw length longer or equal to x |
 | ```screw_nut_radius(type)``` | Radius of matching nut |
+| ```screw_polysink_r(type, z)``` | Countersink hole profile corrected for rounded staircase extrusions. |
 | ```screw_shorter_than(x)``` | Returns longest screw length shorter than or equal to x |
 
 ### Modules
@@ -2939,7 +2943,8 @@ Machine screws and wood screws with various head styles.
 |:--- |:--- |
 | ```screw(type, length, hob_point = 0, nylon = false)``` | Draw specified screw, optionally hobbed or nylon |
 | ```screw_and_washer(type, length, star = false, penny = false)``` | Screw with a washer which can be standard or penny and an optional star washer on top |
-| ```screw_countersink(type)``` | Countersink shape |
+| ```screw_countersink(type, drilled = true)``` | Countersink shape |
+| ```screw_polysink(type, h = 100, alt = false)``` | A countersink hole made from stacked polyholes for printed parts |
 
 ![screws](tests/png/screws.png)
 
@@ -2978,6 +2983,11 @@ Machine screws and wood screws with various head styles.
 |   1 | ```screw(No6_cs_screw, 30)``` |  Screw No6 cs wood x 30mm |
 |   1 | ```screw(No6_screw, 30)``` |  Screw No6 pan wood x 30mm |
 
+### Printed
+| Qty | Filename |
+| ---:|:--- |
+|   1 | polysink.stl |
+
 
 <a href="#top">Top</a>
 
@@ -4558,7 +4568,13 @@ 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 prpoery 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.
+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.
+
+The ends can have screw lugs with four screw positions to choose from, specified by a list of two arrays of four bools.
+If none are enabled then a child object is expected to customise the end and this gets unioned with the blank end.
+If both ends are customised then two children are expected.
+Each child is called twice, once with ```$fasteners``` set to 0 to augment the STL and again with ```$fasteners``` set to 1 to add
+to the assembly, for example to add inserts.
 
 
 [printed/drag_chain.scad](printed/drag_chain.scad) Implementation.
@@ -4581,16 +4597,17 @@ The travel prpoery is how far it can move in each direction, i.e. half the maxim
 | Function | Description |
 |:--- |:--- |
 | ```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 |
+| ```drag_chain_clearance()``` | Clearance around joints. |
 | ```drag_chain_outer_size(type)``` | Link outer dimensions |
 | ```drag_chain_radius(type)``` | The bend radius at the pivot centres |
 | ```drag_chain_z(type)``` | Outside dimension of a 180 bend |
-| ```screw_lug_radius(screw)``` | Radius if a screw lug |
+| ```screw_lug_radius(screw)``` | Radius of a screw lug |
 
 ### Modules
 | Module | Description |
 |:--- |:--- |
 | ```drag_chain_assembly(type, pos = 0)``` | Drag chain assembly |
-| ```drag_chain_link(type, start = false, end = false)``` | One link of the chain, special case for start and end |
+| ```drag_chain_link(type, start = false, end = false, check_kids = true)``` | One link of the chain, special case for start and end |
 | ```drag_chain_screw_positions(type, end)``` | Place children at the screw positions, end = 0 for the start, 1 for the end |
 | ```screw_lug(screw, h = 0)``` | Create a D shaped lug for a screw |
 
@@ -4970,6 +4987,29 @@ The stl must be given a parameterless wrapper in the project that uses it.
 |   1 | pcb_mount_PI_IO_5.stl |
 
 
+<a href="#top">Top</a>
+
+---
+<a name="Press_fit"></a>
+## Press_fit
+Utility for making printed press fit connectors to join printed parts.
+
+Add solvent or glue to make a permanent fixture.
+
+
+[printed/press_fit.scad](printed/press_fit.scad) Implementation.
+
+[tests/press_fit.scad](tests/press_fit.scad) Code for this example.
+
+### Modules
+| Module | Description |
+|:--- |:--- |
+| ```press_fit_peg(h, w = 5, horizontal = false)``` | Make a rounded chamfered peg for easy insertion |
+| ```press_fit_socket(w = 5, h = 50, horizontal = false)``` | Make a square hole to accept a peg |
+
+![press_fit](tests/png/press_fit.png)
+
+
 <a href="#top">Top</a>
 
 ---
@@ -5137,7 +5177,7 @@ Clamp for ribbon cable and polypropylene strip.
 | Module | Description |
 |:--- |:--- |
 | ```ribbon_clamp(ways, screw = screw)``` | Generate STL for given number of ways |
-| ```ribbon_clamp_assembly(ways, screw)``` | Printed part with inserts in place |
+| ```ribbon_clamp_assembly(ways, screw = screw)``` | Printed part with inserts in place |
 | ```ribbon_clamp_fastened_assembly(ways, thickness, screw = screw)``` | Clamp with fasteners in place |
 | ```ribbon_clamp_hole_positions(ways, screw = screw, side = undef)``` | Place children at hole positions |
 | ```ribbon_clamp_holes(ways, h = 20, screw = screw)``` | Drill screw holes |
@@ -5821,7 +5861,7 @@ A sector of a circle between two angles.
 Utility to generate a polhedron by sweeping a 2D profile along a 3D path and utilities for generating paths.
 
 The initial orientation is the Y axis of the profile points towards the initial center of curvature, Frenet-Serret style.
-This means the first three points must not be colinear. Subsequent rotations use the minimum rotation method.
+Subsequent rotations use the minimum rotation method.
 
 The path can be open or closed. If closed sweep ensures that the start and end have the same rotation to line up.
 An additional twist around the path can be specified. If the path is closed this should be a multiple of 360.
@@ -6057,11 +6097,11 @@ Global constants, functions and modules. This file is used directly or indirectl
 | ```circle4n(r, d = undef)``` | Circle with multiple of 4 vertices |
 | ```ellipse(xr, yr)``` | Draw an ellipse |
 | ```extrude_if(h, center = true)``` | Extrudes 2D object to 3D when ```h``` is nonzero, otherwise leaves it 2D |
-| ```hflip()``` | Invert children by doing a 180&deg; flip around the Y axis |
+| ```hflip(flip=true)``` | Invert children by doing a 180&deg; flip around the Y axis |
 | ```right_triangle(width, height, h, center = true)``` | A right angled triangle with the 90&deg; corner at the origin. 3D when ```h``` is nonzero, otherwise 2D |
 | ```semi_circle(r, d = undef)``` | A semi circle in the positive Y domain |
 | ```translate_z(z)``` | Shortcut for Z only translations |
-| ```vflip()``` | Invert children by doing a 180&deg; flip around the X axis |
+| ```vflip(flip=true)``` | Invert children by doing a 180&deg; flip around the X axis |
 
 ![global](tests/png/global.png)
 

scripts/views.py

@@ -308,8 +308,7 @@ def views(target, do_assemblies = None):
                 if printed:
                     print('### 3D Printed parts', file = doc_file)
                     keys = sorted(list(printed.keys()))
-                    for i in range(len(keys)):
-                        p = keys[i]
+                    for i, p in enumerate(keys):
                         print('%s %d x %s |' % ('\n|' if not (i % 3) else '', printed[p]["count"], p), file = doc_file, end = '')
                         if (i % 3) == 2 or i == len(printed) - 1:
                             n = (i % 3) + 1
@@ -324,8 +323,7 @@ def views(target, do_assemblies = None):
                 if routed:
                     print("### CNC Routed parts", file = doc_file)
                     keys = sorted(list(routed.keys()))
-                    for i in range(len(keys)):
-                        r = keys[i]
+                    for i, r in enumerate(keys):
                         print('%s %d x %s |' % ('\n|' if not (i % 3) else '', routed[r]["count"], r), file = doc_file, end = '')
                         if (i % 3) == 2 or i == len(routed) - 1:
                             n = (i % 3) + 1
@@ -340,8 +338,7 @@ def views(target, do_assemblies = None):
                 if sub_assemblies:
                     print("### Sub-assemblies", file = doc_file)
                     keys = sorted(list(sub_assemblies.keys()))
-                    for i in range(len(keys)):
-                        a = keys[i]
+                    for i, a in enumerate(keys):
                         print('%s %d x %s |' % ('\n|' if not (i % 3) else '', sub_assemblies[a], a), file = doc_file, end = '')
                         if (i % 3) == 2 or i == len(keys) - 1:
                             n = (i % 3) + 1

tests/belts.scad

@@ -39,7 +39,7 @@ module belt_test() {
             screw = find_screw(hs_cs_cap, pulley_bore(pulley));
             insert = screw_insert(screw);
 
-            rotate([0, flip ? 180 : 0, 0]) {
+            hflip(flip) {
                 pulley_assembly(pulley);
                 translate_z(pulley_height(pulley) + pulley_offset(pulley) + screw_head_depth(screw, pulley_bore(pulley)))
                     screw(screw, 20);

tests/press_fit.scad

@@ -0,0 +1,71 @@
+//
+// 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 <../printed/press_fit.scad>
+
+module press_fits()
+{
+    thickness = 2;
+    width = 20;
+    vthickness = 4;
+
+    translate([0, width + 2])
+        difference() {
+            cube([width, width, thickness]);
+
+            for(x = [0.25, 0.75])
+                for(y = [0.25, 0.75])
+                    translate([x * width, y * width])
+                        press_fit_socket();
+        }
+
+    union() {
+        cube([width, width, thickness]);
+
+        for(x = [0.25, 0.75])
+            for(y = [0.25, 0.75])
+                translate([x * width, y * width, thickness])
+                    press_fit_peg(h = thickness);
+    }
+
+    translate([width + 2, width + 2])
+        difference() {
+            cube([width, vthickness, width]);
+
+            for(x = [0.25, 0.75])
+                for(y = [0.25, 0.75])
+                    translate([x, 0, y] * width)
+                        rotate([90, 0, 0])
+                            press_fit_socket();
+        }
+
+    translate([width + 2, 0])
+        union() {
+            cube([width, width, thickness]);
+
+            for(x = [0.25, 0.75])
+                for(y = [0.25, 0.75])
+                    translate([x * width, y * width, thickness])
+                        press_fit_peg(h = vthickness, horizontal = true);
+        }
+
+}
+
+
+press_fits();

tests/rails.scad

@@ -23,6 +23,7 @@ use <../utils/layout.scad>
 use <../vitamins/nut.scad>
 
 sheet = 3;
+pos = 1; //[-1 : 0.1 : 1]
 
 module rails()
     layout([for(l = rails) carriage_width(rail_carriage(l))], 20)
@@ -33,7 +34,7 @@ module rails()
             nut = screw_nut(screw);
             washer = screw_washer(screw);
 
-            rail_assembly(rail, length, rail_travel(rail, length) / 2, $i<2 ? grey(20) : "green", $i<2 ? grey(20) : "red");
+            rail_assembly(rail, length, pos * rail_travel(rail, length) / 2, $i<2 ? grey(20) : "green", $i<2 ? grey(20) : "red");
 
             rail_screws(rail, length, sheet + nut_thickness(nut, true) + washer_thickness(washer));
 

tests/screws.scad

@@ -18,20 +18,46 @@
 //
 include <../core.scad>
 
-module screws()
-for(y = [0 : len(screw_lists) -1])
-    for(x = [0 : len(screw_lists[y]) -1]) {
-        screw = screw_lists[y][x];
-        if(screw) {
-             length = screw_head_type(screw) == hs_grub ? 6
-                    : screw_radius(screw) <= 1.5 ? 10
-                    : screw_max_thread(screw) ? screw_longer_than(screw_max_thread(screw) + 5)
-                    : 30;
-            translate([x * 20, y * 20])
-                screw(screw, length);
-        }
+module polysink_stl() {
+    stl("polysink");
+
+    cs_screws = [for(list = screw_lists, screw = list) if(screw_head_type(screw) == hs_cs_cap) screw];
+    n = len(cs_screws);
+    size = [n * 20, 20, 10];
+    difference() {
+        translate([-size.x / n / 2, $preview ? 0 : -size.y / 2, -size.z])
+            cube($preview ? [size.x, size.y / 2, size.z] : size);
+
+        for(i = [0 : n - 1])
+            let(s = cs_screws[i])
+                translate([i * 20, 0]) {
+                    screw_polysink(s, 2 * size.z + 1);
+
+                    translate_z(-size.z)
+                        screw_polysink(s, 2 * size.z + 1, alt = true);
+                }
     }
+}
+
+module screws() {
+    for(y = [0 : len(screw_lists) -1])
+        for(x = [0 : len(screw_lists[y]) -1]) {
+            screw = screw_lists[y][x];
+            if(screw) {
+                 length = screw_head_type(screw) == hs_grub ? 6
+                        : screw_radius(screw) <= 1.5 ? 10
+                        : screw_max_thread(screw) ? screw_longer_than(screw_max_thread(screw) + 5)
+                        : 30;
+                translate([x * 20, y * 20])
+                    screw(screw, length);
+            }
+        }
+        translate([80, 140])
+            polysink_stl();
+}
 
 if($preview)
     let($show_threads = true)
         screws();
+else
+    polysink_stl();

utils/core/global.scad

@@ -39,8 +39,8 @@ function r2sides4n(r) = floor((r2sides(r) + 3) / 4) * 4;
 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()

utils/rounded_polygon.scad

@@ -60,7 +60,7 @@ function rounded_polygon_length(points, tangents) = //! Calculate the length giv
                                    v1 = p1 - c,
                                    v2 = p2 - c,
                                    r = abs(corner.z),
-                                   a = acos((v1 * v2) / sqr(r))) PI * (cross(v1,v2) <= 0 ? a : 360 - a) * r / 180]
+                                   a = acos((v1 * v2) / sqr(r))) r ? PI * (cross(v1, v2) <= 0 ? a : 360 - a) * r / 180 : 0]
      )
     sumv(concat(straights, arcs));
 

utils/sweep.scad

@@ -21,7 +21,7 @@
 //! Utility to generate a polhedron by sweeping a 2D profile along a 3D path and utilities for generating paths.
 //!
 //! The initial orientation is the Y axis of the profile points towards the initial center of curvature, Frenet-Serret style.
-//! This means the first three points must not be colinear. Subsequent rotations use the minimum rotation method.
+//! Subsequent rotations use the minimum rotation method.
 //!
 //! The path can be open or closed. If closed sweep ensures that the start and end have the same rotation to line up.
 //! An additional twist around the path can be specified. If the path is closed this should be a multiple of 360.

vitamins/blowers.scad

@@ -21,7 +21,7 @@
 //                                                   n     d   p   r     r              b   i            r    r                               i    b    s    p    l    g
 //                                                   g     t   t   e     e                  s            e    e                               t         e         l
 //                                                   t     h   h         w              d                w    w                                              t
-//                                                   h                                                  h    s                                         t         t
+//                                                   h                                                   h    s                                         t         t
 RB5015 = ["RB5015", "Blower Runda RB5015",           51.3, 51, 15, 31.5, M4_cap_screw, 26, [27.3, 25.4], 4.5, [[4.3, 45.4], [47.3,7.4]],     20,   14,  1.5, 1.3, 1.2, 15];
 PE4020 = ["PE4020", "Blower Pengda Technology 4020", 40,   40, 20, 27.5, M3_cap_screw, 22, [21.5, 20  ], 3.2, [[37,3],[3,37],[37,37]],       29.3, 17,  1.7, 1.2, 1.3, 13];
 BL40x10 =["BL40x10","Square radial 4010",            40,   40,9.5, 27,   M2_cap_screw, 16, [24,   20  ], 2.4, [[2,2],[38,2],[2,38],[38,38]], 30  , 9.5, 1.5, 1.5, 1.1, 1.5];

vitamins/camera.scad

@@ -29,7 +29,7 @@ function camera_lens(type)          = type[4]; //! Stack of lens parts, can be r
 function camera_connector_pos(type) = type[5]; //! The flex connector block for the camera itself's position
 function camera_connector_size(type)= type[6]; //! The flex connector block for the camera itself's size
 
-module camera_lens(type, offset = 0) //! Draw the lens stack, with optional offset for making a clearance hole
+module camera_lens(type, offset = 0, show_lens = true) //! Draw the lens stack, with optional offset for making a clearance hole
     color(grey(20))
         translate(camera_lens_offset(type))
             for(p = camera_lens(type)) {
@@ -39,24 +39,25 @@ module camera_lens(type, offset = 0) //! Draw the lens stack, with optional offs
                 if(size.x)
                     rounded_rectangle(size + [2 * offset, 2 * offset, round_to_layer(offset)], r, center = false);
                 else
-                    translate_z(size.y)
-                        rotate_extrude()
-                            difference() {
-                                square([r, size.z + round_to_layer(offset)]);
+                    if (show_lens)
+                        translate_z(size.y)
+                            rotate_extrude()
+                                difference() {
+                                    square([r, size.z + round_to_layer(offset)]);
 
-                                if(app)
-                                    translate([0, size.z])
-                                        hull() {
-                                            translate([0, -eps])
-                                                square([app.y, eps * 2]);
+                                    if(app)
+                                        translate([0, size.z])
+                                            hull() {
+                                                translate([0, -eps])
+                                                    square([app.y, eps * 2]);
 
-                                            translate([0, -app.z])
-                                                square([app.x, app.z]);
-                                        }
-                            }
+                                                translate([0, -app.z])
+                                                    square([app.x, app.z]);
+                                            }
+                                }
             }
 
-module camera(type) {           //! Draw specified PCB camera
+module camera(type, show_lens = true) {           //! Draw specified PCB camera
     vitamin(str("camera(", type[0], "): ", type[1]));
     pcb = camera_pcb(type);
 
@@ -64,7 +65,7 @@ module camera(type) {           //! Draw specified PCB camera
         pcb(pcb);
 
     translate_z(pcb_thickness(pcb)) {
-        camera_lens(type);
+        camera_lens(type, show_lens = show_lens);
 
         conn = camera_connector_size(type);
         if(conn) {

vitamins/inserts.scad

@@ -29,7 +29,7 @@
 //                          d         d          h    d    d
 //                                         d
 //
-F1BM2   = [ "F1BM2",    4.0, 3.6, 3.2, 2,   3.0,  1.0, 3.4, 3.1 ];
+F1BM2   = [ "F1BM2",   4.0, 3.6, 3.2, 2,   3.0,  1.0, 3.4, 3.1 ];
 F1BM2p5 = [ "F1BM2p5", 5.8, 4.6, 4.0, 2.5, 3.65, 1.6, 4.4, 3.9 ];
 F1BM3   = [ "F1BM3",   5.8, 4.6, 4.0, 3,   3.65, 1.6, 4.4, 3.9 ];
 F1BM4   = [ "F1BM4",   8.2, 6.3, 5.6, 4,   5.15, 2.3, 6.0, 5.55 ];

vitamins/mains_socket.scad

@@ -116,7 +116,7 @@ module mains_socket(type) { //! Draw specified 13A socket
             cylinder(r = screw_clearance_radius(screw), h = 100, center = true);
 
             translate_z(height)
-                screw_countersink(screw);
+                screw_countersink(screw, drilled = false);
         }
     }
 }

vitamins/rail.scad

@@ -46,12 +46,16 @@ function carriage_pitch_y(type)      = type[6]; //! Screw hole y pitch
 function carriage_screw(type)        = type[7]; //! Carriage screw type
 function carriage_screw_depth(type)  = 2 * screw_radius(carriage_screw(type)); //! Carriage thread depth
 
+function rail_holes(type, length) = //! Number of holes in a rail given its ```length```
+    floor((length - 2 * rail_end(type)) / rail_pitch(type)) + 1;
+
 module rail_hole_positions(type, length, first = 0, screws = 100, both_ends = true) { //! Position children over screw holes
     pitch = rail_pitch(type);
-    holes = floor((length - 2 * rail_end(type)) / pitch) + 1;
-    for(i = [first : holes - 1 - first])
-        if(i < screws || (holes - i <= screws && both_ends))
-            translate([i * pitch - length / 2 + (length - (holes -1) * pitch) / 2, 0, 0])
+    holes = rail_holes(type, length);
+    last = first + screws;
+    for(i = [first : holes - 1], j = holes - 1 - i)
+        if(i < last || both_ends && (j >= first && j < last))
+            translate([i * pitch - length / 2 + (length - (holes - 1) * pitch) / 2, 0])
                 children();
 }
 
@@ -104,24 +108,27 @@ module carriage(type, rail, end_colour = grey(20), wiper_colour = grey(20)) { //
 
     module carriage_end(type, end_w, end_h, end_l) {
         wiper_length = 0.5;
-        color(wiper_colour) translate_z(-end_l/2) linear_extrude(wiper_length)
+        color(wiper_colour) translate_z(-end_l / 2) linear_extrude(wiper_length)
             difference() {
-                translate([-end_w/2, carriage_clearance(type)])
+                translate([-end_w / 2, carriage_clearance(type)])
                     square([end_w, end_h]);
+
                 cutout();
             }
-        color(end_colour) translate_z(wiper_length-end_l/2) linear_extrude(end_l-wiper_length)
+        color(end_colour) translate_z(wiper_length-end_l / 2) linear_extrude(end_l - wiper_length)
             difference() {
-                translate([-end_w/2, carriage_clearance(type)])
+                translate([-end_w / 2, carriage_clearance(type)])
                     square([end_w, end_h]);
+
                 cutout();
             }
     }
 
-    translate([-(block_l+end_l)/2,0,0])
+    translate([-(block_l + end_l) / 2, 0])
         rotate([90, 0, 90])
             carriage_end(type, end_w, end_h, end_l);
-    translate([(block_l+end_l)/2,0,0])
+
+    translate([(block_l + end_l) / 2, 0])
         rotate([90, 0, -90])
             carriage_end(type, end_w, end_h, end_l);
 }
@@ -171,7 +178,6 @@ module rail_assembly(type, length, pos, carriage_end_colour = grey(20), carriage
 
     translate([pos, 0])
         carriage(rail_carriage(type), type,  carriage_end_colour, carriage_wiper_colour);
-
 }
 
 module rail_screws(type, length, thickness, screws = 100) { //! Place screws in the rail
@@ -187,6 +193,6 @@ module rail_screws(type, length, thickness, screws = 100) { //! Place screws in
             screw(end_screw, end_screw_len);
 
     translate_z(rail_screw_height(type, screw))
-        rail_hole_positions(type, length, index_screws, screws)
+        rail_hole_positions(type, length, index_screws, min(screws, rail_holes(type, length)) - 2 * index_screws)
             screw(screw, screw_len);
 }

vitamins/rails.scad

@@ -33,11 +33,11 @@ SSR15_carriage = [ 40.3, 23.3, 34, 24, 4.5, 0,  26, M4_cap_screw ];
 //
 //
 //                Wr  Hr   E    P   D    d    h
-MGN5 = [ "MGN5",  5,  3.6, 5,   15, 3.5, 2.4, 0.8, M2_cs_cap_screw, MGN5_carriage, M2_cs_cap_screw ]; // Screw holes too small for M2 heads
+MGN5 = [ "MGN5",  5,  3.6, 5,   15, 3.6, 2.4, 0.8, M2_cs_cap_screw, MGN5_carriage, M2_cs_cap_screw ]; // Screw holes too small for M2 heads
 MGN7 = [ "MGN7",  7,  5,   5,   15, 4.3, 2.4, 2.6, M2_cap_screw,    MGN7_carriage, M2_cs_cap_screw ];
 MGN9 = [ "MGN9",  9,  6,   7.5, 20, 6.0, 3.5, 3.5, M3_cap_screw,    MGN9_carriage, M3_cs_cap_screw ];
 MGN12= [ "MGN12", 12, 8,   10,  25, 6.0, 3.5, 4.5, M3_cap_screw,   MGN12_carriage, M3_cs_cap_screw ];
-MGN12H=[ "MGN12H",12, 8,    10, 25, 6.0, 3.5, 4.5, M3_cap_screw,   MGN12H_carriage,M3_cs_cap_screw ];
+MGN12H=[ "MGN12H",12, 8,   10,  25, 6.0, 3.5, 4.5, M3_cap_screw,   MGN12H_carriage,M3_cs_cap_screw ];
 MGN15= [ "MGN15", 15, 10,  10,  40, 6.0, 3.5, 5.0, M3_cap_screw,   MGN15_carriage, M3_cs_cap_screw ];
 SSR15= [ "SSR15", 15, 12.5,10,  60, 7.5, 4.5, 5.3, M4_cap_screw,   SSR15_carriage, M4_cs_cap_screw ];
 

vitamins/screw.scad

@@ -19,6 +19,8 @@
 
 //
 //! Machine screws and wood screws with various head styles.
+//!
+//! For an explanation of ```screw_polysink()``` see <https://hydraraptor.blogspot.com/2020/12/sinkholes.html>.
 //
 include <../utils/core/core.scad>
 
@@ -41,9 +43,13 @@ function screw_pilot_hole(type)       = type[11];    //! Pilot hole radius for w
 function screw_clearance_radius(type) = type[12];    //! Clearance hole radius
 function screw_nut_radius(type) = screw_nut(type) ? nut_radius(screw_nut(type)) : 0; //! Radius of matching nut
 function screw_boss_diameter(type) = max(washer_diameter(screw_washer(type)) + 1, 2 * (screw_nut_radius(type) + 3 * extrusion_width)); //! Boss big enough for nut trap and washer
-function screw_head_depth(type, d) = screw_head_height(type) ? 0 : screw_head_radius(type) - d / 2; //! How far a counter sink head will go into a straight hole diameter d
+function screw_head_depth(type, d = 0) =             //! How far a counter sink head will go into a straight hole diameter d
+    screw_head_height(type)
+        ? 0
+        : let(r = screw_radius(type)) screw_head_radius(type) - max(r, d / 2) + r / 5;
 
 function screw_longer_than(x) = x <=  5 ?  5 : //! Returns shortest screw length longer or equal to x
+                                x <=  6 ?  6 :
                                 x <=  8 ?  8 :
                                 x <= 10 ? 10 :
                                 x <= 12 ? 12 :
@@ -109,6 +115,27 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                     cylinder(r = rad + eps, h = shank);
     }
 
+    module cs_head(socket_rad, socket_depth) {
+        head_t = rad / 5;
+        head_height = head_rad + head_t;
+
+        rotate_extrude()
+            difference() {
+                polygon([[0, 0], [head_rad, 0], [head_rad, -head_t], [0, -head_height]]);
+
+                translate([0, -socket_depth + eps])
+                    square([socket_rad, 10]);
+            }
+
+        translate_z(-socket_depth)
+            linear_extrude(socket_depth)
+                difference() {
+                    circle(socket_rad + 0.1);
+
+                    children();
+                }
+    }
+
     explode(length + 10) {
         if(head_type == hs_cap) {
             color(colour) {
@@ -201,63 +228,76 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
         }
 
         if(head_type == hs_cs) {
-            head_height = head_rad;
             socket_rad = 0.6 * head_rad;
             socket_depth = 0.3 * head_rad;
             socket_width = 1;
-            color(colour) {
-                rotate_extrude()
-                    difference() {
-                        polygon([[0, 0], [head_rad, 0], [0, -head_height]]);
+            color(colour)
+                cs_head(socket_rad, socket_depth) {
+                    square([2 * socket_rad, socket_width], center = true);
+                    square([socket_width, 2 * socket_rad], center = true);
+                }
 
-                        translate([0, -socket_depth + eps])
-                            square([socket_rad + 0.1, 10]);
-                    }
-
-                translate_z(-socket_depth)
-                    linear_extrude(socket_depth)
-                        difference() {
-                            circle(socket_rad + 0.1);
-
-                            square([2 * socket_rad, socket_width], center = true);
-                            square([socket_width, 2 * socket_rad], center = true);
-                        }
-            }
             shaft(socket_depth);
         }
 
         if(head_type == hs_cs_cap) {
-            head_height = head_rad;
-            color(colour) {
-                rotate_extrude()
-                    difference() {
-                        polygon([[0, 0], [head_rad, 0], [0, -head_height]]);
+            color(colour)
+                cs_head(socket_rad, socket_depth)
+                    circle(socket_rad, $fn = 6);
 
-                        translate([0, -socket_depth + eps])
-                            square([socket_rad, 10]);
-                    }
-
-                translate_z(-socket_depth)
-                    linear_extrude(socket_depth)
-                        difference() {
-                            circle(socket_rad + 0.1);
-
-                            circle(socket_rad, $fn = 6);
-                        }
-            }
             shaft(socket_depth);
         }
     }
 }
 
-module screw_countersink(type) { //! Countersink shape
+module screw_countersink(type, drilled = true) { //! Countersink shape
     head_type   = screw_head_type(type);
     head_rad    = screw_head_radius(type);
-    head_height = head_rad;
+    rad = screw_radius(type);
+    head_t = rad / 5;
+    head_height = head_rad + head_t;
 
     if(head_type == hs_cs || head_type == hs_cs_cap)
         translate_z(-head_height)
-             cylinder(h = head_height, r1 = 0, r2 = head_rad);
+            if(drilled)
+                cylinder(h = head_height + eps, r1 = 0, r2 = head_rad + head_t);
+            else
+                intersection() {
+                    cylinder(h = head_height + eps, r1 = 0, r2 = head_rad + head_t);
+
+                    cylinder(h = head_height + eps, r = head_rad + eps);
+                }
+}
+
+function screw_polysink_r(type, z) = //! Countersink hole profile corrected for rounded staircase extrusions.
+    let(rad = screw_radius(type),
+        head_t = rad / 5,
+        head_rad = screw_head_radius(type)
+    )
+    limit(head_rad + head_t - z + (sqrt(2) - 1) * layer_height / 2, screw_clearance_radius(type), head_rad);
+
+module screw_polysink(type, h = 100, alt = false) { //! A countersink hole made from stacked polyholes for printed parts
+    head_depth = screw_head_depth(type);
+    assert(head_depth, "Not a countersunk screw");
+    layers = ceil(head_depth / layer_height);
+    rmin = screw_clearance_radius(type);
+    sides = sides(rmin);
+    lh = layer_height + eps;
+    render(convexity = 5)
+        for(side = [0, 1]) mirror([0, 0, side]) {
+            for(i = [0 : layers - 1])
+                translate_z(i * layer_height) {
+                    r = screw_polysink_r(type, i * layer_height + layer_height / 2);
+                    if(alt)
+                        rotate(i % 2 == layers % 2 ? 180 / sides : 0)
+                            poly_cylinder(r = r, h = lh, center = false, sides = sides);
+                    else
+                        poly_cylinder(r = r, h = lh, center = false);
+                }
+
+            translate_z(layers * layer_height)
+                poly_cylinder(r = rmin, h = h / 2 - layers * layer_height, center = false);
+        }
 }
 
 module screw_and_washer(type, length, star = false, penny = false) { //! Screw with a washer which can be standard or penny and an optional star washer on top

vitamins/screws.scad

@@ -107,14 +107,14 @@ No6_screw        = ["No6", "No6 pan wood",      hs_pan, 3.5, 6.7, 2.2,    0,   0
 No6_cs_screw     = ["No6_cs", "No6 cs wood",    hs_cs,  3.5, 7.0, 0,      0,   0, 0,   M4_washer, false,    No6_pilot_radius, No6_clearance_radius];
 
 screw_lists = [
-[ M2_cap_screw, M2p5_cap_screw, M3_cap_screw,    M4_cap_screw, M5_cap_screw, M6_cap_screw, M8_cap_screw],
-[ 0,            0,              M3_low_cap_screw],
-[ 0,            0,              M3_hex_screw,    M4_hex_screw, M5_hex_screw, M6_hex_screw, M8_hex_screw],
-[ 0,            M2p5_pan_screw, M3_pan_screw,    M4_pan_screw, M5_pan_screw, M6_pan_screw, No632_pan_screw],
-[ 0,            No2_screw,      No4_screw,       No6_screw,    No6_cs_screw],
-[ 0,            M2_cs_cap_screw,M3_cs_cap_screw, M4_cs_cap_screw],
-[ 0,            M2_dome_screw,  M3_dome_screw,   M4_dome_screw],
-[ 0,            0,              M3_grub_screw,   M4_grub_screw]
+[ M2_cap_screw,    M2p5_cap_screw, M3_cap_screw,    M4_cap_screw, M5_cap_screw, M6_cap_screw, M8_cap_screw],
+[ 0,               0,              M3_low_cap_screw],
+[ M2_cs_cap_screw, 0,              M3_cs_cap_screw, M4_cs_cap_screw],
+[ M2_dome_screw,   0,              M3_dome_screw,   M4_dome_screw],
+[ 0,               0,              M3_hex_screw,    M4_hex_screw, M5_hex_screw, M6_hex_screw, M8_hex_screw],
+[ 0,               M2p5_pan_screw, M3_pan_screw,    M4_pan_screw, M5_pan_screw, M6_pan_screw, No632_pan_screw],
+[ No2_screw,       0,              No4_screw,       No6_screw,    No6_cs_screw],
+[ 0,               0,              M3_grub_screw,   M4_grub_screw]
 ];
 
 use <screw.scad>

vitamins/sheets.scad

@@ -38,7 +38,7 @@ PMMA8     = [ "PMMA8",     "Sheet acrylic",           8, [1,   1,   1,   0.5  ],
 PMMA10    = [ "PMMA10",    "Sheet acrylic",          10, [1,   1,   1,   0.5  ], false];   // ~3/8"
 glass2    = [ "glass2",    "Sheet glass",             2, [1,   1,   1,   0.25 ], false];
 DiBond    = [ "DiBond",    "Sheet DiBond",            3, [0.2, 0.2, 0.2, 1    ], false];
-DiBond6   = [ "DiBond6",   "Sheet DiBond",            6, "RoyalBlue",            false];
+DiBond6   = [ "DiBond6",   "Sheet DiBond",            6, [0.2, 0.2, 0.2, 1    ], false];
 Cardboard = [ "Cardboard", "Corrugated cardboard",    5, [0.8, 0.6, 0.3, 1    ], false];
 FoilTape  = [ "FoilTape",  "Aluminium foil tape",   0.05,[0.9, 0.9, 0.9, 1    ], false];
 Foam20    = [ "Foam20",    "Foam sponge",             20,[0.3, 0.3, 0.3, 1    ], true];