Merge branch 'martinbudden-spelling_corrections'

Tiny PCBs now shown in a third line.

docs/usage.md

@@ -1,7 +1,7 @@
 # NopSCADlib usage
 
 ## Requirements
-1. OpenSCAD 2019.05 or later, download it from here: https://www.openscad.org/downloads.html
+1. OpenSCAD 2021.01 or later, download it from here: https://www.openscad.org/downloads.html
 1. Python 2.7+ or 3.6+ from https://www.python.org/downloads/
 1. ImageMagick 7 www.imagemagick.org
 
@@ -270,6 +270,22 @@ The target config file is selected by generating `target.scad` that includes `co
 The rest of the project includes `target.scad` to use the configuration.
 Additionally all the generated file directories (assemblies, bom, stls, dxfs, etc.) are placed in a sub-directory called `<target_name>`.
 
+The build system will look for a `<target_name>_assembly` module and use it as the top level module instead of `main_assembly` if it it exists.
+That allows the project description to be target specific if the top level modules are in different scad files.
+The top level assembly instructions and assembly contents could also be different if appropriate.
+
+If the top level module is just a shell wrapper that simply includes one other assembly, with no additional parts, then it is removed from the build instructions and
+the assembly it calls becomes the top level. This allows a different project description for each target but only one set of top level instructions without repeating them.
+
+### Costed BOMs
+
+A costed bill of materials can be made by opening the generated file `bom/bom.csv` in a spreadsheet program using a single quote as the string delimiter and comma as the field separator.
+That gets a list of part descriptions and quantities to which prices can be added to get the total cost and perhaps a URL of where to buy each part.
+
+If a Python file called `parts.py` is found then `bom.py` will attempt to call functions for each part to get a price and URL.
+Any functions not found are printed, so you can see the format expected.
+The function are passed the quantity to allow them to calculate volume discounts, etc.
+
 ### Other libraries
 
 The build scripts need to be able to locate the source files where the modules to generate the STL files and assemblies reside. They will search all the scad files

examples/MainsBreakOutBox/bom/bom.csv

@@ -0,0 +1,16 @@
+'Ferrule for 1.5mm^2 wire - not shown',  3
+'Wire blue 30/0.25mm strands, length 150mm - not shown',  2
+'Wire brown 30/0.25mm strands, length 150mm - not shown',  2
+'Wire green & yellow 30/0.25mm strands, length 150mm - not shown',  2
+'IEC inlet for ATX',  1
+'Heatfit insert M3',  2
+'4mm shielded jack socket blue',  2
+'4mm shielded jack socket brown',  1
+'4mm shielded jack socket green',  2
+'Mains socket 13A',  1
+'Nut M3 x 2.4mm nyloc',  6
+'Screw M3 cs cap x 12mm',  2
+'Screw M3 cs cap x 20mm',  2
+'Screw M3 dome x 10mm',  4
+'Heatshrink sleeving ID 3.2mm x 15mm - not shown',  8
+'Washer  M3 x 7mm x 0.5mm', 10

examples/MainsBreakOutBox/bom/bom.json

@@ -3,6 +3,7 @@
         "name": "base_assembly",
         "big": null,
         "ngb": false,
+        "zoomed": 0,
         "count": 1,
         "assemblies": {},
         "vitamins": {
@@ -22,6 +23,7 @@
         "name": "feet_assembly",
         "big": null,
         "ngb": false,
+        "zoomed": 0,
         "count": 1,
         "assemblies": {
             "base_assembly": 1
@@ -49,6 +51,7 @@
         "name": "mains_in_assembly",
         "big": null,
         "ngb": false,
+        "zoomed": 0,
         "count": 1,
         "assemblies": {
             "feet_assembly": 1
@@ -86,6 +89,7 @@
         "name": "main_assembly",
         "big": null,
         "ngb": false,
+        "zoomed": 0,
         "count": 1,
         "assemblies": {
             "mains_in_assembly": 1

gallery/readme.md

@@ -1,40 +1,30 @@
 # A gallery of projects made with NopSCADlib
-<a name="TOP"></a>
 ## ArduinoThermostat
 Arduino thermostat to control a beer fridge to use it as an environmental chamber.
 
 ![](ArduinoThermostat.png)
 
-
-<a name="TOP"></a>
 ## EnviroPlus
 Environmental monitor using Enviro+ sensor board and a Raspberry Pi Zero.
 
 ![](EnviroPlus.png)
 
-
-<a name="TOP"></a>
 ## FilamentDryBox
 A small fan oven with a spool holder to keep the filament warm and dry.
 
 ![](FilamentDryBox.png)
 
-
-<a name="TOP"></a>
 ## HydraBot
 Current state of HydraRaptor after being modified for laser engraving.
 
 ![](HydraBot.png)
 
 
-<a name="TOP"></a>
 ## IOT 50V PSU
 WiFi controllable PSU
 
 ![](IOT_50V_PSU.png)
 
-
-<a name="TOP"></a>
 ## Lab ATX PSU
 Bench power supply built around an ATX PSU.
 
@@ -47,15 +37,11 @@ Bench power supply built around an ATX PSU.
 
 
 
-
-<a name="TOP"></a>
 ## Laser Load
 15kV dummy load for testing CO2 laser PSUs
 
 ![](Laser_load.png)
 
-
-<a name="TOP"></a>
 ## MainsBreakOutBox
 13A socket break out box with 4mm jacks to measure voltage and / or load current and earth leakage current.
 
@@ -72,8 +58,6 @@ Earth leakage can be measured Canadian CSA style by disconnected the neutral lin
 
 ![](MainsBreakOutBox.png)
 
-
-<a name="TOP"></a>
 ## Mains Box
 Mains isolated and variable supply with metering.
 
@@ -81,15 +65,11 @@ Mains isolated and variable supply with metering.
 
 
 
-
-<a name="TOP"></a>
 ## SunBot
 A solar tracker to keep a solar panel pointing at the sun.
 
 ![](SunBot.png)
 
-
-<a name="TOP"></a>
 ## Turntable
 WiFi enabled remote control turntable for photography
 
@@ -97,8 +77,6 @@ WiFi enabled remote control turntable for photography
 
 Was actually made from DiBond but shown made with carbon fibre here.
 
-
-<a name="TOP"></a>
 ## Variac
 Motorised variac with WiFi control, see [hydraraptor.blogspot.com/2018/04/esp8266-spi-spy](https://hydraraptor.blogspot.com/2018/04/esp8266-spi-spy.html)
 
@@ -106,4 +84,3 @@ Motorised variac with WiFi control, see [hydraraptor.blogspot.com/2018/04/esp826
 
 
 
-

global_defs.scad

@@ -27,15 +27,16 @@
 //  Setting $_bom in the local file overrides it in the local file but not in the libs.
 //
 rr_green = [0, 146/255, 0];                                               // RepRap logo colour
+crimson  = [220/255, 20/255, 60/255];
 
 $_bom           = is_undef($bom)             ? 0      : $bom;             // 0 no bom, 1 assemblies and stls, 2 vitamins as well
 $exploded       = is_undef($explode)         ? 0      : $explode;         // 1 for exploded view
-layer_height    = is_undef($layer_height)    ? 0.25   : $layer_height;    // layer heigth when printing
+layer_height    = is_undef($layer_height)    ? 0.25   : $layer_height;    // layer height when printing
 extrusion_width = is_undef($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    : $cnc_bit_r;       // minimum tool radius when milling 2D objects
 pp1_colour      = is_undef($pp1_colour)      ? rr_green : $pp1_colour;    // printed part colour 1, RepRap logo colour
-pp2_colour      = is_undef($pp2_colour)      ? "Crimson"  : $pp2_colour;  // printed part colour 2
+pp2_colour      = is_undef($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
@@ -53,9 +54,10 @@ $fs = extrusion_width / 2;
 function round_to_layer(z) = ceil(z / layer_height) * layer_height;
 // Some additional named colours
 function grey(n) = [0.01, 0.01, 0.01] * n;                                          //! Generate a shade of grey to pass to color().
-gold                            = [255/255, 215/255, 0/255];
-brass                           = [255/255, 220/255, 100/255];
 silver                          = [0.75, 0.75, 0.75];
+gold                            = [255, 215,   0] / 255;
+brass                           = [255, 220, 100] / 255;
+copper                          = [230, 140,  51] / 255;
 
 /*
  * Enums

lib.scad

@@ -26,7 +26,10 @@ include <vitamins/psus.scad>
 include <vitamins/pcbs.scad>
 
 include <vitamins/batteries.scad>
+include <vitamins/bearing_blocks.scad>
 include <vitamins/blowers.scad>
+include <vitamins/bldc_motors.scad>
+include <vitamins/box_sections.scad>
 include <vitamins/bulldogs.scad>
 include <vitamins/buttons.scad>
 include <vitamins/cameras.scad>
@@ -37,7 +40,6 @@ include <vitamins/extrusion_brackets.scad>
 include <vitamins/geared_steppers.scad>
 include <vitamins/hot_ends.scad>
 include <vitamins/inserts.scad>
-include <vitamins/kp_pillow_blocks.scad>
 include <vitamins/ldrs.scad>
 include <vitamins/leadnuts.scad>
 include <vitamins/led_meter.scad>
@@ -47,12 +49,12 @@ include <vitamins/mains_sockets.scad>
 include <vitamins/modules.scad>
 include <vitamins/panel_meters.scad>
 include <vitamins/pillars.scad>
+include <vitamins/pillow_blocks.scad>
 include <vitamins/pin_headers.scad>
 include <vitamins/pulleys.scad>
 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>
@@ -89,7 +91,7 @@ use <utils/gears.scad>
 use <utils/hanging_hole.scad>
 use <utils/fillet.scad>
 use <utils/rounded_polygon.scad>
-use <utils/rounded_right_triangle.scad>
+use <utils/rounded_triangle.scad>
 use <utils/layout.scad>
 use <utils/round.scad>
 use <utils/offset.scad>

libtest.scad

@@ -33,6 +33,8 @@
 //!
 //! See [usage](docs/usage.md) for requirements, installation instructions and a usage guide.
 //!
+//! A list of changes classified as breaking, additions or fixes is maintained in [CHANGELOG.md](CHANGELOG.md).
+//!
 //! <img src="libtest.png" width="100%"/>
 //
 // This file shows all the parts in the library.
@@ -41,8 +43,11 @@ include <lib.scad>
 
 use <tests/ball_bearings.scad>
 use <tests/batteries.scad>
+use <tests/bearing_blocks.scad>
 use <tests/belts.scad>
+use <tests/BLDC_motors.scad>
 use <tests/blowers.scad>
+use <tests/box_sections.scad>
 use <tests/bulldogs.scad>
 use <tests/buttons.scad>
 use <tests/cable_strips.scad>
@@ -62,7 +67,6 @@ use <tests/hot_ends.scad>
 use <tests/IECs.scad>
 use <tests/inserts.scad>
 use <tests/jack.scad>
-use <tests/KP_pillow_blocks.scad>
 use <tests/leadnuts.scad>
 use <tests/LDRs.scad>
 use <tests/LEDs.scad>
@@ -78,6 +82,7 @@ use <tests/opengrab.scad>
 use <tests/panel_meters.scad>
 use <tests/PCBs.scad>
 use <tests/pillars.scad>
+use <tests/pillow_blocks.scad>
 use <tests/press_fit.scad>
 use <tests/PSUs.scad>
 use <tests/pulleys.scad>
@@ -86,7 +91,6 @@ use <tests/ring_terminals.scad>
 use <tests/rockers.scad>
 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>
@@ -117,6 +121,7 @@ use <tests/flat_hinge.scad>
 use <tests/foot.scad>
 use <tests/handle.scad>
 use <tests/PCB_mount.scad>
+use <tests/pocket_handle.scad>
 use <tests/printed_box.scad>
 use <tests/printed_pulleys.scad>
 use <tests/ribbon_clamp.scad>
@@ -180,7 +185,10 @@ translate([x5, cable_grommets_y + 250])
 translate([950, 600])
     box_test();
 
-translate([890, 750])
+translate([830, 770])
+    pocket_handles();
+
+translate([950, 750])
     printed_boxes();
 
 translate([850, 1330])
@@ -201,8 +209,8 @@ ball_bearings_y = pillars_y + 40;
 pulleys_y = ball_bearings_y +40;
 hot_ends_y = pulleys_y + 60;
 linear_bearings_y = hot_ends_y + 50;
-sheets_y = linear_bearings_y + 100;
-pcbs_y = sheets_y + 40;
+sheets_y = linear_bearings_y + 90;
+pcbs_y = sheets_y + 60;
 displays_y = pcbs_y + 170;
 fans_y = displays_y + 80;
 transformers_y = fans_y + 120;
@@ -362,10 +370,10 @@ extrusions_y = panel_meters_y + 80;
 translate([x3, veroboard_y])
     veroboard_test();
 
-translate([x3 + 70, veroboard_y + 30])
+translate([x3 + 60, veroboard_y + 20])
     geared_steppers();
 
-translate([x3 + 140, veroboard_y + 20])
+translate([x3 + 160, ssrs_y])
     pcb_mounts();
 
 translate([x3 + 170, veroboard_y + 16])
@@ -420,6 +428,9 @@ extrusion_brackets_y = rails_y + 250;
 sk_brackets_y = extrusion_brackets_y + 80;
 kp_pillow_blocks_y = sk_brackets_y + 50;
 scs_bearing_blocks_y = kp_pillow_blocks_y + 60;
+cable_strip_y = fans_y + 50;
+box_sections_y = cable_strip_y;
+BLDC_y = sheets_y;
 
 translate([x4 + 200, belts_y + 58]) {
     belt_test();
@@ -435,7 +446,7 @@ translate([x4 + 175, belts_y, -20])
 translate([x4, rails_y + 130])
     rails();
 
-translate([770, fans_y + 50])
+translate([770, cable_strip_y])
     cable_strips();
 
 translate([x4, kp_pillow_blocks_y])
@@ -453,6 +464,11 @@ translate([x4 + 120, extrusion_brackets_y])
 translate([x4, scs_bearing_blocks_y])
     scs_bearing_blocks();
 
+translate([x4, BLDC_y])
+    bldc_motors();
+
+translate([x6, box_sections_y])
+    box_sections();
 
 translate([x6, 125])
     light_strips();

printed/butt_box.scad

@@ -54,7 +54,7 @@ function bbox(screw, sheets, base_sheet, top_sheet, span, size, name = "bbox", s
  [ screw, sheets, base_sheet, top_sheet, span, size.x, size.y, size.z, name, skip_blocks, star_washers ];
 
 function bbox_volume(type) = bbox_width(type) * bbox_depth(type) * bbox_height(type) / 1000000; //! Internal volume in litres
-function bbox_area(type) = let(w =  bbox_width(type), d = bbox_depth(type), h = bbox_height(type)) //! Internal surdface area in m^2
+function bbox_area(type) = let(w =  bbox_width(type), d = bbox_depth(type), h = bbox_height(type)) //! Internal surface area in m^2
     2 * (w * d + w * h + d * h) / 1000000;
 
 module bbox_shelf_blank(type) { //! 2D template for a shelf

printed/door_hinge.scad

@@ -45,7 +45,7 @@ function door_hinge_stat_screw() = stat_screw;              //! Screw use to fas
 function door_hinge_stat_width() = stat_width;              //! Width of the stationary part
 function door_hinge_stat_length() = stat_length;            //! Length of the stationary part
 
-module door_hinge_hole_positions(dir = 0) {                 //! Position chidren at the door hole positions
+module door_hinge_hole_positions(dir = 0) {                 //! Position children at the door hole positions
     hole_pitch = width - 10;
 
     for(side = [-1, 1])

printed/door_latch.scad

@@ -57,7 +57,7 @@ module door_latch_stl() { //! Generates the STL for the printed part
         }
 }
 
-module door_latch_assembly(sheet_thickness = 3) { //! The assembly for a specified sheet thickess
+module door_latch_assembly(sheet_thickness = 3) { //! The assembly for a specified sheet thickness
     washer = screw_washer(screw);
     nut = screw_nut(screw);
 

printed/drag_chain.scad

@@ -20,7 +20,7 @@
 //
 //! Parametric cable drag chain to limit the bend radius of a cable run.
 //!
-//! Each link has a maximum bend angle of 45°, so the mininium radius is proportional to the link length.
+//! Each link has a maximum bend angle of 45°, so the minimum 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.
 //!

printed/fan_guard.scad

@@ -17,7 +17,7 @@
 // If not, see <https://www.gnu.org/licenses/>.
 
 //
-//! Pintable fan finger guard to match the specified fan. To be `include`d, not `use`d.
+//! Printable fan finger guard to match the specified fan. To be `include`d, not `use`d.
 //!
 //! The ring spacing as well as the number of spokes can be specified, if zero a gasket is generated instead of a guard.
 //

printed/flat_hinge.scad

@@ -40,7 +40,7 @@ function hinge_knuckles(type)    = type[6]; //! How many knuckles
 function hinge_screw(type)       = type[7]; //! Screw type to mount it
 function hinge_screws(type)      = type[8]; //! How many screws
 function hinge_clearance(type)   = type[9]; //! Clearance between knuckles
-function hinge_margin(type)      = type[10]; //! How far to keep the screws from the knuckes
+function hinge_margin(type)      = type[10]; //! How far to keep the screws from the knuckles
 
 function flat_hinge(name, size, pin_d, knuckle_d, knuckles, screw, screws, clearance, margin) = //! Construct the property list for a flat hinge.
  [name, size.x, size.y, size.z, pin_d, knuckle_d, knuckles, screw, screws, clearance, margin];
@@ -73,7 +73,7 @@ module hinge_male(type, female = false) {       //! The half with the stationary
     assert(kr > pr, "knuckle diameter must be bigger than the pin diameter");
 
     n = hinge_knuckles(type);
-    assert(n >= 3, "must be at least three knuckes");
+    assert(n >= 3, "must be at least three knuckles");
     mn = ceil(n / 2);                           // Male knuckles
     fn = floor(n / 2);                          // Female knuckles
     gap = hinge_clearance(type);

printed/pocket_handle.scad

@@ -0,0 +1,154 @@
+//
+// NopSCADlib Copyright Chris Palmer 2021
+// 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/>.
+//
+
+//
+//! Customisable pocket handle
+//
+include <../core.scad>
+
+function pocket_handle(hand_size = [90, 40, 40], slant = 35, screw = M3_cs_cap_screw, panel_t = 3, wall = 4, rad = 4) = //! Construct a pocket_handle property list
+    [hand_size, slant, screw, panel_t, wall, rad];
+
+function pocket_handle_hand_size(type) = type[0]; //! Size of the hole for the fingers
+function pocket_handle_slant(type)     = type[1]; //! Upward slant of the hand hole
+function pocket_handle_screw(type)     = type[2]; //! Screw type, can be countersunk or not
+function pocket_handle_panel_t(type)   = type[3]; //! Thickness of the panel it is mounted in
+function pocket_handle_wall(type)      = type[4]; //! Wall thickness
+function pocket_handle_rad(type)       = type[5]; //! Min corner rad
+
+function pocket_handle_flange(type) = //! Size of the flange
+    let(w = pocket_handle_wall(type),
+        f = washer_diameter(screw_washer(pocket_handle_screw(type))) + 2 + w,
+        s = pocket_handle_hand_size(type))
+             [s.x + 2 * f, s.y + 2 * f, w];
+
+module pocket_handle_hole_positions(type) { //! Place children at screw hole positions
+    f = pocket_handle_flange(type);
+    h = pocket_handle_hand_size(type);
+    x_pitch = (f.x + h.x) / 4;
+    y_pitch = (f.y + h.y) / 4;
+
+    for(x = [-1, 1], y = [-1, 1])
+        translate([x * x_pitch, y * y_pitch])
+            children();
+}
+
+module pocket_handle_holes(type, h = 0) { //! Panel cutout and screw holes
+    hand = pocket_handle_hand_size(type);
+    w = pocket_handle_wall(type);
+    slot = [hand.x + 2 * w, hand.y + 2 * w];
+    t = pocket_handle_panel_t(type);
+    clearance = norm([slot.y, t]) - slot.y + 0.2; // has to be enough clearance for the diagonal to swing it in
+
+    extrude_if(h) {
+        pocket_handle_hole_positions(type)
+            drill(screw_clearance_radius(pocket_handle_screw(type)), 0);
+
+        rounded_square([slot.x  + clearance, slot.y + clearance], pocket_handle_rad(type) + w + clearance / 2);
+    }
+}
+
+module pocket_handle(type) { //! Generate STL for pocket_handle
+    f = pocket_handle_flange(type);
+    r = pocket_handle_rad(type);
+    s = pocket_handle_slant(type);
+    o = f.z * tan(s);
+    h = pocket_handle_hand_size(type);
+    t = pocket_handle_panel_t(type);
+    w = pocket_handle_wall(type);
+    screw = pocket_handle_screw(type) ;
+
+    stl("pocket_handle")
+        union() {
+            difference() {
+                hull() {
+                    rounded_rectangle(f, r);
+
+                    translate_z(f.z - eps)
+                        rounded_rectangle([f.x + 2 * o, f.y + 2 * o, eps], r + o);
+                }
+                hull() {
+                    rounded_rectangle([h.x, h.y, f.z + eps], r);
+
+                    translate_z(-eps)
+                        rounded_rectangle([h.x + 2 * o, h.y + 2 * o, eps], r + o);
+                }
+                pocket_handle_hole_positions(type) {
+                    if(screw_head_height(screw))
+                        translate_z(-eps)
+                            poly_cylinder(r = screw_clearance_radius(screw), h = f.z + 2 * eps, center = false);
+                    else
+                        screw_polysink(screw, h = 2 * f.z + eps, alt = true);
+                }
+            }
+
+            translate_z(f.z)
+                linear_extrude(t)
+                    difference() {
+                        rounded_square([h.x + 2 * w, h.y + 2 * w], r + w);
+
+                        rounded_square([h.x, h.y], r);
+                    }
+
+            translate_z(f.z + t)
+                difference() {
+                    height = h.z - f.z - t;
+                    hull() {
+                        rounded_rectangle([h.x + 2 * w, h.y + 2 * w, eps], r + w);
+
+                        translate((height + w) * [0, sin(s), cos(s)])
+                            rounded_rectangle([h.x + 2 * w, h.y + 2 * w, eps], r + w);
+                    }
+
+                    hull() {
+                        translate_z(-eps)
+                            rounded_rectangle([h.x, h.y, eps], r);
+
+                        translate(height * [0, sin(s), cos(s)])
+                            rounded_rectangle([h.x, h.y, eps], r);
+                    }
+                }
+        }
+}
+
+module pocket_handle_assembly(type) { //! Assembly with fasteners in place
+    f = pocket_handle_flange(type);
+    screw = pocket_handle_screw(type);
+    nut = screw_nut(screw);
+    t = pocket_handle_panel_t(type);
+    washers = screw_head_height(screw) ? 2 : 1;
+    screw_length = screw_length(screw, f.z + t, washers, nyloc = true);
+
+    translate_z(f.z + t / 2) hflip() {
+        stl_colour(pp1_colour)
+            pocket_handle(type);
+
+        pocket_handle_hole_positions(type) {
+            translate_z(f.z + t)
+                explode(15, true)
+                    nut_and_washer(nut, true);
+
+            vflip()
+                if(washers == 2)
+                    screw_and_washer(screw, screw_length);
+                else
+                    screw(screw, screw_length);
+        }
+    }
+}

scripts/bom.py

@@ -31,6 +31,12 @@ from set_config import *
 import json
 import re
 
+try:
+    import parts
+    got_parts_py = True
+except:
+    got_parts_py = False
+
 def find_scad_file(mname):
     for filename in os.listdir(source_dir):
         if filename[-5:] == ".scad":
@@ -46,6 +52,18 @@ def find_scad_file(mname):
                             return filename
     return None
 
+def main_assembly(target):
+    file = None
+    if target:
+        assembly = target + "_assembly"
+        file = find_scad_file(assembly)
+    if not file:
+        assembly = "main_assembly"
+        file = find_scad_file(assembly)
+    if not file:
+        raise Exception("can't find source for " + assembly)
+    return assembly, file
+
 class Part:
     def __init__(self, args):
         self.count = 1
@@ -61,6 +79,7 @@ class BOM:
         self.name = name
         self.big = None
         self.ngb = False
+        self.zoomed = 0
         self.count = 1
         self.vitamins = {}
         self.printed = {}
@@ -75,6 +94,7 @@ class BOM:
              "name"       : self.name,
              "big"        : self.big,
              "ngb"        : self.ngb,
+             "zoomed"     : self.zoomed,
              "count"      : self.count,
              "assemblies" : assemblies,
              "vitamins"   : {v : self.vitamins[v].data() for v in self.vitamins},
@@ -115,6 +135,33 @@ class BOM:
             return ass
         return ass.replace("assembly", "assemblies")
 
+    def print_CSV(self,  file = None):
+        i = 0
+        for part in sorted(self.vitamins):
+            i += 1
+            if ': ' in part:
+                part_no, description = part.split(': ')
+            else:
+                part_no, description = "", part
+            qty = self.vitamins[part].count
+            if got_parts_py:
+                match = re.match(r'^.*\((.*?)[,\)].*$', part_no)
+                if match and not match.group(1).startswith('"'):
+                    part_no = part_no.replace('(' + match.group(1), '_' + match.group(1) + '(').replace('(, ', '(')
+                func = 'parts.' + part_no.replace('(', '(%d, ' % qty).replace(', )', ')')
+                func = func.replace('true',  'True').replace('false', 'False').replace('undef', 'None')
+                try:
+                    price, url = eval(func)
+                    print("'%s',%3d,%.2f,'=B%d*C%d',%s" % (description, qty, price, i, i, url), file=file)
+                except:
+                    if part_no:
+                        print("%s not found in parts.py" % func)
+                    print("'%s',%3d" % (description, qty), file=file)
+            else:
+                print("'%s',%3d" % (description, qty), file=file)
+        if got_parts_py:
+            print(",'=SUM(B1:B%d)',,'=SUM(D1:D%d)'" %(i, i), file=file)
+
     def print_bom(self, breakdown, file = None):
         if self.vitamins:
             print("Vitamins:", file=file)
@@ -219,28 +266,20 @@ def parse_bom(file = "openscad.log", name = None):
     return main
 
 def usage():
-    print("\nusage:\n\tbom [target_config] [<accessory_name>_assembly] - Generate BOMs for a project or an accessory to a project.")
+    print("\nusage:\n\tbom [target_config] - Generate BOMs for a project.")
     sys.exit(1)
 
-def boms(target = None, assembly = None):
+def boms(target = None):
     try:
         bom_dir = set_config(target, usage) + "bom"
-        if assembly:
-            bom_dir += "/accessories"
-            if not os.path.isdir(bom_dir):
-                os.makedirs(bom_dir)
-        else:
-            assembly = "main_assembly"
-            if os.path.isdir(bom_dir):
-                shutil.rmtree(bom_dir)
-                sleep(0.1)
-            os.makedirs(bom_dir)
+        if os.path.isdir(bom_dir):
+            shutil.rmtree(bom_dir)
+            sleep(0.1)
+        os.makedirs(bom_dir)
         #
-        # Find the scad file that makes the module
+        # Find the scad file that makes the main assembly
         #
-        scad_file = find_scad_file(assembly)
-        if not scad_file:
-            raise Exception("can't find source for " + assembly)
+        assembly, scad_file = main_assembly(target)
         #
         # make a file to use the module
         #
@@ -257,8 +296,9 @@ def boms(target = None, assembly = None):
 
         main = parse_bom("openscad.echo", assembly)
 
-        if assembly == "main_assembly":
-            main.print_bom(True, open(bom_dir + "/bom.txt","wt"))
+        main.print_bom(True, open(bom_dir + "/bom.txt","wt"))
+
+        main.print_CSV(open(bom_dir + "/bom.csv","wt"))
 
         for ass in main.assemblies:
             with open(bom_dir + "/" + ass + ".txt", "wt") as f:
@@ -276,20 +316,8 @@ def boms(target = None, assembly = None):
         sys.exit(1)
 
 if __name__ == '__main__':
-    if len(sys.argv) > 3: usage()
+    if len(sys.argv) > 2: usage()
 
-    if len(sys.argv) == 3:
-        target, assembly = sys.argv[1], sys.argv[2]
-    else:
-        if len(sys.argv) == 2:
-            if sys.argv[1][-9:] == "_assembly":
-                target, assembly = None, sys.argv[1]
-            else:
-                target, assembly = sys.argv[1], None
-        else:
-            target, assembly = None, None
+    target = sys.argv[1] if len(sys.argv) == 2 else None
 
-    if assembly:
-        if assembly[-9:] != "_assembly": usage()
-
-    boms(target, assembly)
+    boms(target)

scripts/changelog.py

@@ -0,0 +1,164 @@
+#!/usr/bin/env python
+
+#
+# NopSCADlib Copyright Chris Palmer 2021
+# 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/>.
+#
+#! Creates the changelog from the git log
+
+from __future__ import print_function
+import sys
+import subprocess
+import re
+
+filename = 'CHANGELOG.md'
+
+def tag_version(t):
+    """ Format a version tag """
+    return 'v%d.%d.%d' % t
+
+def initials(name):
+    """ Convert full name to initials with a tooltip """
+    i = ''.join([n[0].upper() + '.' for n in name.split(' ')])
+    return '[%s](# "%s")' % (i, name)
+
+def get_remote_url():
+    """ Get the git remote URL for the repository """
+    url = subprocess.check_output(["git", "config", "--get", "remote.origin.url"]).decode("utf-8").strip("\n")
+    if url.startswith("git@"):
+        url = url.replace(":", "/", 1).replace("git@", "https://", 1)
+    if url.endswith(".git"):
+        url = url[:-4]
+    return url
+
+def iscode(word):
+    """ try to guess if the word is code """
+    endings = ['()', '*']
+    starts = ['$', '--']
+    anywhere = ['.', '_', '=', '[', '/']
+    words = ['center', 'false', 'true', 'ngb']
+
+    for w in words:
+        if word == w:
+            return True
+
+    for end in endings:
+        if word.endswith(end):
+            return True
+
+    for start in starts:
+        if word.startswith(start):
+            return True
+
+    for any in anywhere:
+        if word.find(any) >= 0:
+            return True
+
+    return False
+
+def codify(word, url):
+    """ if a word is deemed code enclose it backticks """
+    if word:
+        if re.match(r'#[0-9]+', word):
+            return '[%s](%s "show issue")' % (word, url + '/issues/' + word[1:])
+        if iscode(word):
+            return  '`' + word + '`'
+    return word
+
+
+def fixup_comment(comment, url):
+    """ markup code words and fix new paragraphs """
+    result = ''
+    word = ''
+    code = False
+    for i, c in enumerate(comment):
+        if c == '`' or code:                # Already a code block
+            result += c                     # Copy verbatim
+            if c == '`': code = not code    # Keep track of state
+        else:
+            if c in ' \n' or (c == '.' and (i + 1 == len(comment) or comment[i + 1] in ' \n')): # if a word terminator
+                result += codify(word, url) + c  # Add codified word before terminator
+                word = ''
+            else:
+                word += c                   # Accumulate next word
+    result += codify(word, url)             # In case comment ends without a terminator
+    return result.replace('\n\n','\n\n * ') # Give new paragraphs a bullet point
+
+class Commit(): # members dynamically added from commit_fields
+    pass
+
+blurb = """
+# %s Changelog
+This changelog is generated by `changelog.py` using manually added semantic version tags to classify commits as breaking changes, additions or fixes.
+
+"""
+
+if __name__ == '__main__':
+    url = get_remote_url()
+
+    commit_fields = {
+        'hash':    "%H|",       # commit commit_hash
+        'tag':     "%D|",       # tag
+        'author': "%aN|",       # author name
+        'date': "  %as|",       # author date short form
+        'comment': "%B~"        # body
+    }
+
+    # Produce the git log
+    format = ''.join([v for k, v in commit_fields.items()])
+    text = subprocess.check_output(["git", "log", "--topo-order", "--format=" + format]).decode("utf-8")
+
+    # Process the log into a list of Commit objects
+    commits = []
+    for line in text.split('~'):
+        line = line.strip('\n')
+        if line:
+            fields = line.split('|')
+            commit = Commit()
+            for i, k in enumerate(commit_fields):
+                exec('commit.%s = """%s"""' % (k, fields[i]), locals())
+            # Convert version tag to tuple
+            if commit.tag:
+                match = re.match(r'.*tag: v([0-9]+)\.([0-9]+)\.([0-9]+).*', commit.tag)
+                commit.tag = (int(match.group(1)), int(match.group(2)), int(match.group(3))) if match else ''
+            commits.append(commit)
+
+    # Format the results from the Commit objects
+    with open(filename, "wt") as file:
+        print(blurb % url.split('/')[-1], file = file)
+        for i, c in enumerate(commits):
+            if c.tag:
+                ver = tag_version(c.tag)
+                level, type = (3, 'Fixes') if c.tag[2] else (2, 'Additions') if c.tag[1] else (1, 'Breaking Changes') if c.tag[0] else (1, 'First publicised version')
+
+                # Find the previous tagged commit
+                j = i + 1
+                diff = ''
+                while j < len(commits):
+                    if commits[j].tag:
+                        last_ver = tag_version(commits[j].tag)
+                        diff = '[...](%s "diff with %s")' % (url + '/compare/' + last_ver + '...' + ver, last_ver)
+                        break
+                    j += 1
+
+                # Print verson info
+                print('%s [%s](%s "show release") %s %s' % ('#' * (level + 1), ver, url + '/releases/tag/' + ver, type, diff), file = file)
+
+            # Print commits excluding merges
+
+            if not c.comment.startswith('Merge branch') and not c.comment.startswith('Merge pull') and not re.match(r'U..ated changelog.*', c.comment):
+                print('* %s [`%s`](%s "show commit") %s %s\n' % (c.date, c.hash[:7], url + '/commit/' + c.hash, initials(c.author), fixup_comment(c.comment, url)), file = file)

scripts/deps.py

@@ -18,6 +18,7 @@
 #
 import os
 from set_config import source_dir
+from colorama import Fore
 
 def mtime(file):
     if os.path.isfile(file):
@@ -41,13 +42,13 @@ def read_deps(dname):
 def check_deps(target, dname):
     target_mtime = mtime(target)
     if not target_mtime:
-        return target + " missing"
+        return Fore.CYAN + target + " missing" + Fore.WHITE
     if not os.path.isfile(dname):
-        return "no deps"
+        return Fore.CYAN + "no deps" + Fore.WHITE
     deps = read_deps(dname)
     for dep in deps:
         if mtime(dep) > target_mtime:
-            return dep + ' changed'
+            return Fore.CYAN + dep + ' changed' + Fore.WHITE
     return None
 
 def source_dirs(bom_dir):

scripts/exports.py

@@ -28,7 +28,10 @@ from set_config import *
 import time
 import times
 from deps import *
+from tmpdir import *
 import json
+import shutil
+from colorama import Fore, init
 
 def bom_to_parts(bom_dir, part_type, assembly = None):
     #
@@ -43,7 +46,7 @@ def bom_to_parts(bom_dir, part_type, assembly = None):
             if words:
                 last_word = words[-1]
                 if last_word.endswith(suffix):
-                   part_files.append(last_word[:-4] + '.' + part_type)
+                    part_files.append(last_word[:-4] + '.' + part_type)
     return part_files
 
 def usage(t):
@@ -62,12 +65,20 @@ def make_parts(target, part_type, parts = None):
     #
     top_dir = set_config(target, lambda: usage(part_type))
     target_dir = top_dir + part_type + 's'
-    deps_dir = top_dir + "deps"
+    deps_dir = target_dir + "/deps"
     bom_dir = top_dir + "bom"
+    tmp_dir = mktmpdir(top_dir)
+
     if not os.path.isdir(target_dir):
         os.makedirs(target_dir)
+
     if not os.path.isdir(deps_dir):
         os.makedirs(deps_dir)
+
+    old_deps = top_dir + 'deps'  #old location
+    if os.path.isdir(old_deps):
+         shutil.rmtree(old_deps)
+
     times.read_times(target_dir)
     #
     # Decide which files to make
@@ -120,18 +131,18 @@ def make_parts(target, part_type, parts = None):
                                         changed = check_deps(part_file, dname)
                                         changed = times.check_have_time(changed, part)
                                         if part_type == 'stl' and not changed and not part in bounds_map:
-                                            changed = "No bounds"
+                                            changed = Fore.CYAN + "No bounds" + Fore.WHITE
                                         if changed:
                                             print(changed)
                                             #
                                             # make a file to use the module
                                             #
-                                            part_maker_name = part_type + ".scad"
+                                            part_maker_name = tmp_dir + '/' + part_type + ".scad"
                                             with open(part_maker_name, "w") as f:
-                                                f.write("use <%s/%s>\n" % (dir, filename))
+                                                f.write("use <%s/%s>\n" % (reltmp(dir, target), filename))
                                                 f.write("%s();\n" % module);
                                             t = time.time()
-                                            openscad.run("-D$bom=1", "-d", dname, "-o", part_file, part_maker_name)
+                                            openscad.run("-o", part_file, part_maker_name, "-D$bom=1", "-d", dname)
                                             times.add_time(part, t)
                                             if part_type == 'stl':
                                                 bounds = c14n_stl.canonicalise(part_file)
@@ -145,6 +156,10 @@ def make_parts(target, part_type, parts = None):
         with open(bounds_fname, 'w') as outfile:
             json.dump(bounds_map, outfile, indent = 4)
     #
+    # Remove tmp dir
+    #
+    rmtmpdir(tmp_dir)
+    #
     # List the ones we didn't find
     #
     if targets:

scripts/gallery.py

@@ -68,9 +68,10 @@ def gallery(force):
                             match = re.match(r"^(#+).*$", line)
                             if match:
                                 line = '#' + line
-                        if line == '---\n':
-                            break;
-                        print(line[:-1], file = output_file)
+                        if line == '---\n' or line == '<span></span>\n':
+                            break
+                        if line != '<a name="TOP"></a>\n':
+                            print(line[:-1], file = output_file)
             else:
                 print(Fore.MAGENTA + "Can't find", document, Fore.WHITE);
     with open(target_dir + "/readme.html", "wt") as html_file:

scripts/openscad.py

@@ -25,19 +25,25 @@ from __future__ import print_function
 import subprocess, sys
 
 def run_list(args, silent = False, verbose = False):
-    cmd = ["openscad", "--hardwarnings"] + args
+    cmd = ["openscad"] + args + ["--hardwarnings"]
     if not silent:
         for arg in cmd:
             print(arg, end=" ")
         print()
     with open("openscad.log", "w") as log:
         rc = subprocess.call(cmd, stdout = log, stderr = log)
-    for line in open("openscad.log", "rt"):
+    log_file = "openscad.echo" if "openscad.echo" in cmd else "openscad.log"
+    bad = False
+    for line in open(log_file, "rt"):
         if verbose or 'ERROR:' in line or 'WARNING:' in line:
+            bad = True
             print(line[:-1])
     if rc:
         sys.exit(rc)
 
+    if bad:
+        sys.exit(1)
+
 def run(*args):
     run_list(list(args), False)
 

scripts/options.py

@@ -17,9 +17,10 @@
 # If not, see <https://www.gnu.org/licenses/>.
 #
 
-# Set command line options from enviroment variables and check if they have changed
+# Set command line options from environment variables and check if they have changed
 
 import json, os, deps
+from colorama import Fore, init
 
 def check_options(dir = '.'):
     global options, options_mtime
@@ -37,7 +38,7 @@ def check_options(dir = '.'):
 
 def have_changed(changed, target):
     if not changed and deps.mtime(target) < options_mtime:
-        return "command line options changed"
+        return Fore.CYAN + "command line options changed" + Fore.WHITE
     return changed
 
 def list():

scripts/plateup.py

@@ -26,8 +26,10 @@ import sys
 import c14n_stl
 from set_config import *
 from deps import *
-from shutil import copyfile
+import shutil
 import re
+import time
+import times
 
 source_dirs = { "stl" : "platters", "dxf" : "panels" }
 target_dirs = { "stl" : "printed",  "dxf" : "routed" }
@@ -41,22 +43,32 @@ def plateup(target, part_type, usage = None):
     target_dir = parts_dir + '/' + target_dirs[part_type]
     source_dir1 = source_dirs[part_type]
     source_dir2 = top_dir + source_dirs[part_type]
+
     #
     # Loop through source directories
     #
-    used = []
+    all_used = []
     all_sources = []
+    all_parts = []
+    read_times = False
     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)
+
+        if not read_times:
+            times.read_times(target_dir)
+            read_times = True
         #
         # Make the deps dir
         #
-        deps_dir = dir + "/deps"
+        deps_dir = parts_dir + "/deps"
         if not os.path.isdir(deps_dir):
             os.makedirs(deps_dir)
+
+        if os.path.isdir(dir + '/deps'): #old deps
+            shutil.rmtree(dir + '/deps')
         #
         # Decide which files to make
         #
@@ -65,42 +77,55 @@ def plateup(target, part_type, usage = None):
         #
         # Run OpenSCAD on the source files to make the targets
         #
+        target_def = ['-D$target="%s"' % target] if target else []
+        cwd_def = ['-D$cwd="%s"' % os.getcwd().replace('\\', '/')]
         for src in sources:
             src_file = dir + '/' + src
-            part_file = target_dir + '/' + src[:-4] + part_type
+            part =  src[:-4] + part_type
+            all_parts.append(part)
+            part_file = target_dir + '/' + part
+            uses_file = deps_dir + '/' + src[:-4] + 'txt'
             dname = deps_name(deps_dir, src)
-            changed = check_deps(part_file, dname)
+            oldest = part_file if mtime(part_file) < mtime(uses_file) else uses_file
+            changed = check_deps(oldest, dname)
+            used = []
             if changed:
                 print(changed)
-                target_def = ['-D$target="%s"' % target] if target else []
-                cwd_def = ['-D$cwd="%s"' % os.getcwd().replace('\\', '/')]
+                t = time.time()
                 openscad.run_list(["-D$bom=1"] + target_def + cwd_def + ["-d", dname, "-o", part_file, src_file])
                 if part_type == 'stl':
                     c14n_stl.canonicalise(part_file)
+                times.add_time(part, t)
                 log_name = 'openscad.log'
+                #
+                # Add the files on the BOM to the used list
+                #
+                with open(log_name) as file:
+                    for line in file.readlines():
+                        match = re.match(r'^ECHO: "~(.*?\.' + part_type + r').*"$', line)
+                        if match:
+                            used.append(match.group(1))
+                with open(uses_file, "wt") as file:
+                    for part in used:
+                        print(part, file = file)
             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))
+                with open(uses_file, "rt") as file:
+                    for line in file:
+                        used.append(line[:-1])
+            all_used += used
+
     copied = []
     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:
+            if file.endswith('.' + part_type) and not file in all_used:
                 src = parts_dir + '/' + file
                 dst = target_dir + '/' + file
                 if mtime(src) > mtime(dst):
                     print("Copying %s to %s" % (src, dst))
-                    copyfile(src, dst)
+                    shutil.copyfile(src, dst)
                 copied.append(file)
         #
         # Remove any cruft
@@ -111,3 +136,12 @@ def plateup(target, part_type, usage = None):
                 if not file in targets and not file in copied:
                     print("Removing %s" % file)
                     os.remove(target_dir + '/' + file)
+
+        targets = [file[:-4] + 'txt' for file in all_sources]
+        for file in os.listdir(deps_dir):
+            if file.endswith('.' + 'txt'):
+                if not file in targets:
+                    print("Removing %s" % file)
+                    os.remove(deps_dir + '/' + file)
+
+        times.print_times(all_parts)

scripts/readme.md

@@ -8,6 +8,7 @@ They should work with both Python 2 and Python 3.
 |:---|:---|
 | `bom.py` | Generates BOM files for the project. |
 | `c14n_stl.py` | OpenSCAD produces randomly ordered STL files. This script re-orders them consistently so that GIT can tell if they have changed or not. |
+| `changelog.py` | Creates the changelog from the git log |
 | `doc_scripts.py` | Makes this document and doc/usage.md. |
 | `dxfs.py` | Generates DXF files for all the routed parts listed on the BOM or a specified list. |
 | `gallery.py` | Finds projects and adds them to the gallery. |

scripts/render.py

@@ -30,6 +30,7 @@ from tests import do_cmd, update_image, colour_scheme, background
 from deps import mtime
 from colorama import init
 import json
+from tmpdir import *
 
 def usage():
     print("\nusage:\n\trender [target_config] - Render images of the stl and dxf files.");
@@ -40,6 +41,7 @@ def render(target, type):
     # Make the target directory
     #
     top_dir = set_config(target, usage)
+    tmp_dir = mktmpdir(top_dir)
     target_dir = top_dir + type + 's'
     bom_dir = top_dir + 'bom'
     if not os.path.isdir(target_dir):
@@ -80,7 +82,7 @@ def render(target, type):
         # make a file to import the stl
         #
         if mtime(part_file) > mtime(png_name):
-            png_maker_name = "png.scad"
+            png_maker_name = tmp_dir + "/png.scad"
             pp1 = [0, 146/255, 0]
             colour = pp1
             if part in colours:
@@ -88,15 +90,19 @@ def render(target, type):
                 if not '[' in colour:
                     colour = '"' + colour + '"'
             with open(png_maker_name, "w") as f:
-                f.write('color(%s) import("%s");\n' % (colour, part_file))
+                f.write('color(%s) import("%s");\n' % (colour, reltmp(part_file, target)))
             cam = "--camera=0,0,0,70,0,315,500" if type == 'stl' else "--camera=0,0,0,0,0,0,500"
             render = "--preview" if type == 'stl' or colour != pp1 else "--render"
-            tmp_name = 'tmp.png'
-            openscad.run(colour_scheme, "--projection=p", "--imgsize=4096,4096", cam, render, "--autocenter", "--viewall", "-o", tmp_name, png_maker_name);
+            tmp_name = tmp_dir + '/' + part[:-4] + '.png'
+            openscad.run("-o", tmp_name, png_maker_name, colour_scheme, "--projection=p", "--imgsize=4096,4096", cam, render, "--autocenter", "--viewall");
             do_cmd(("magick "+ tmp_name + " -trim -resize 280x280 -background %s -gravity Center -extent 280x280 -bordercolor %s -border 10 %s"
                     % (background, background, tmp_name)).split())
             update_image(tmp_name, png_name)
             os.remove(png_maker_name)
+    #
+    # Remove tmp dir
+    #
+    rmtmpdir(tmp_dir)
 
 if __name__ == '__main__':
     init()

scripts/set_config.py

@@ -69,17 +69,22 @@ def set_config(target, usage = None):
         sys.exit(1)
 
     fname = source_dir + "/target.scad"
-    text = "include <config_%s.scad>\n" % target;
-    line = ""
+    text = ['include <config_%s.scad>\n' % target,
+            '$target = "%s";\n' % target,
+            '$cwd="%s";\n' % os.getcwd().replace('\\', '/')
+    ]
+
+    lines = [""]
     try:
         with open(fname,"rt") as f:
-            line = f.read()
+            lines = f.readlines()
     except:
         pass
 
-    if line != text:
+    if lines != text:
         with open(fname,"wt") as f:
-            f. write(text);
+            for t in text:
+                f. write(t);
     return target + "/"
 
 def usage():

scripts/tests.py

@@ -34,6 +34,7 @@ import shutil
 from deps import *
 from blurb import *
 from colorama import Fore
+from tmpdir import *
 
 w = 4096
 h = w
@@ -59,7 +60,8 @@ def compare_images(a, b, c):
     with open(log_name, 'w') as output:
         do_cmd(("magick compare -metric AE -fuzz %d%% %s %s %s" % (fuzz, a, b, c)).split(), output = output)
     with open(log_name, 'r') as f:
-        pixels = int(float(f.read().strip()))
+        pixels = f.read().strip()
+        pixels = int(float(pixels if pixels.isnumeric() else -1))
     os.remove(log_name)
     return pixels
 
@@ -94,6 +96,7 @@ def usage():
 
 def tests(tests):
     scad_dir = "tests"
+    tmp_dir = mktmpdir(scad_dir + '/')
     deps_dir = scad_dir + "/deps"
     png_dir  = scad_dir + "/png"
     bom_dir  = scad_dir + "/bom"
@@ -114,7 +117,7 @@ def tests(tests):
         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);
+            openscad.run(scad_name, "-o", png_name, colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,50,0,340,500", "--autocenter", "--viewall");
             do_cmd(["magick", png_name, "-trim", "-resize", "1280", "-bordercolor", background, "-border", "10", png_name])
     else:
         #
@@ -170,7 +173,7 @@ def tests(tests):
                     impl_name = None
 
             if libtest:
-                vsplit = "AJR" + chr(ord('Z') + 1)
+                vsplit = "AIR" + 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:
@@ -234,8 +237,8 @@ def tests(tests):
             if changed:
                 print(changed)
                 t = time.time()
-                tmp_name = 'tmp.png'
-                openscad.run_list(options.list() + ["-D$bom=2", colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,70,0,315,500", "--autocenter", "--viewall", "-d", dname, "-o", tmp_name, scad_name]);
+                tmp_name = tmp_dir + '/tmp.png'
+                openscad.run_list([scad_name, "-o", tmp_name] + options.list() + ["-D$bom=2", colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,70,0,315,500", "--autocenter", "--viewall", "-d", dname]);
                 times.add_time(scad_name, t)
                 do_cmd(["magick", tmp_name, "-trim", "-resize", "1000x600", "-bordercolor", background, "-border", "10", tmp_name])
                 update_image(tmp_name, png_name)
@@ -303,6 +306,11 @@ def tests(tests):
     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()
+    #
+    # Remove tmp dir
+    #
+    rmtmpdir(tmp_dir)
+
     do_cmd(('codespell -L od ' + doc_name).split())
 
 if __name__ == '__main__':

scripts/times.py

@@ -44,7 +44,7 @@ def got_time(name):
 
 def check_have_time(changed, name):
     if not changed and not got_time(name):
-        changed = "no previous time"
+        changed = Fore.CYAN + "no previous time" + Fore.WHITE
     return changed
 
 def add_time(name, start):

scripts/tmpdir.py

@@ -0,0 +1,40 @@
+#
+# NopSCADlib Copyright Chris Palmer 2021
+# 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/>.
+#
+"""
+Make a directory for tmp files.
+"""
+import os
+import time
+
+def mktmpdir(top_dir):
+    tmp_dir = top_dir + 'tmp'
+    if not os.path.isdir(tmp_dir):
+        os.makedirs(tmp_dir)
+    else:
+        for file in os.listdir(tmp_dir):
+            os.remove(tmp_dir + '/' + file)
+    return tmp_dir
+
+def reltmp(dir, target):
+    return dir if os.path.isabs(dir) else '../../' + dir if target else '../' + dir
+
+def rmtmpdir(tmp_dir):
+    os.rmdir(tmp_dir)
+    while os.path.isdir(tmp_dir):
+        time.sleep(0.1)

scripts/views.py

@@ -38,6 +38,7 @@ import shutil
 import re
 import copy
 from colorama import Fore
+from tmpdir import *
 
 def is_assembly(s):
     return s[-9:] == '_assembly' or s[-11:] == '_assemblies'
@@ -76,12 +77,12 @@ def bom_to_assemblies(bom_dir, bounds_map):
     #
     if flat_bom:
         ass = flat_bom[-1]
-        if len(ass["assemblies"]) < 2 and not ass["vitamins"] and not ass["printed"] and not ass["routed"]:
+        if len(ass["assemblies"]) == 1 and not ass["vitamins"] and not ass["printed"] and not ass["routed"]:
             flat_bom = flat_bom[:-1]
     return [assembly["name"] for  assembly in flat_bom]
 
 def eop(doc_file, last = False, first = False):
-    print('<span></span>', file = doc_file)     # An invisable marker for page breaks because markdown takes much longer if the document contains a div
+    print('<span></span>', file = doc_file)     # An invisible marker for page breaks because markdown takes much longer if the document contains a div
     if not first:
         print('[Top](#TOP)', file = doc_file)
     if not last:
@@ -129,8 +130,9 @@ def views(target, do_assemblies = None):
     # Make the target directory
     #
     top_dir = set_config(target, usage)
+    tmp_dir = mktmpdir(top_dir)
     target_dir = top_dir + 'assemblies'
-    deps_dir = top_dir + "deps"
+    deps_dir = target_dir + "/deps"
     bom_dir = top_dir + "bom"
     if not os.path.isdir(target_dir):
         os.makedirs(target_dir)
@@ -159,6 +161,7 @@ def views(target, do_assemblies = None):
     # Find all the scad files
     #
     main_blurb = None
+    main_assembly, main_file = bom.main_assembly(target)
     pngs = []
     for dir in source_dirs(bom_dir):
         if os.path.isdir(dir):
@@ -183,6 +186,7 @@ def views(target, do_assemblies = None):
                                     #
                                     for ass in flat_bom:
                                         if ass["name"] == real_name:
+                                            zoomed = ass['zoomed']
                                             if not "blurb" in ass:
                                                 ass["blurb"] = blurb.scrape_module_blurb(lines[:line_no])
                                             break
@@ -204,20 +208,21 @@ def views(target, do_assemblies = None):
                                             changed = check_deps(png_name, dname)
                                             changed = times.check_have_time(changed, png_name)
                                             changed = options.have_changed(changed, png_name)
-                                            tmp_name = 'tmp.png'
+                                            tmp_name = tmp_dir + '/' + real_name + '.png'
                                             if changed:
                                                 print(changed)
                                                 #
                                                 # make a file to use the module
                                                 #
-                                                png_maker_name = 'png.scad'
+                                                png_maker_name = tmp_dir + '/png.scad'
                                                 with open(png_maker_name, "w") as f:
-                                                    f.write("use <%s/%s>\n" % (dir, filename))
+                                                    f.write("use <%s/%s>\n" % (reltmp(dir, target), filename))
                                                     f.write("%s();\n" % module);
                                                 t = time.time()
                                                 target_def = ['-D$target="%s"' % target] if target else []
                                                 cwd_def = ['-D$cwd="%s"' % os.getcwd().replace('\\', '/')]
-                                                openscad.run_list(options.list() + target_def + cwd_def + ["-D$pose=1", "-D$explode=%d" % explode, colour_scheme, "--projection=p", "--imgsize=4096,4096", "--autocenter", "--viewall", "-d", dname, "-o", tmp_name, png_maker_name]);
+                                                view_def = ['--viewall', '--autocenter'] if not (zoomed & (1 << explode)) else ['--camera=0,0,0,55,0,25,140']
+                                                openscad.run_list(["-o", tmp_name, png_maker_name] + options.list() + target_def + cwd_def + view_def + ["-D$pose=1", "-D$explode=%d" % explode, colour_scheme, "--projection=p", "--imgsize=4096,4096", "-d", dname]);
                                                 times.add_time(png_name, t)
                                                 do_cmd(["magick", tmp_name, "-trim", "-resize", "1004x1004", "-bordercolor", background, "-border", "10", tmp_name])
                                                 update_image(tmp_name, png_name)
@@ -228,7 +233,7 @@ def views(target, do_assemblies = None):
                                                 update_image(tmp_name, tn_name)
                                     done_assemblies.append(real_name)
                                 else:
-                                    if module == 'main_assembly':
+                                    if module == main_assembly:
                                         main_blurb = blurb.scrape_module_blurb(lines[:line_no])
                         line_no += 1
     #
@@ -242,9 +247,6 @@ def views(target, do_assemblies = None):
         project = ' '.join(word[0].upper() + word[1:] for word in os.path.basename(os.getcwd()).split('_'))
         print('<a name="TOP"></a>', file = doc_file)
         print('# %s' % project, file = doc_file)
-        main_file = bom.find_scad_file('main_assembly')
-        if not main_file:
-            raise Exception("can't find source for main_assembly")
         text = blurb.scrape_blurb(source_dir + '/' + main_file)
         blurbs = blurb.split_blurb(text)
         if len(text):
@@ -439,6 +441,10 @@ def views(target, do_assemblies = None):
                 dst.write(line)
                 i += 1
     #
+    # Remove tmp dir
+    #
+    rmtmpdir(tmp_dir)
+    #
     # Spell check
     #
     do_cmd(('codespell -L od ' + top_dir + 'readme.md').split())

tests/BLDC_motors.scad

@@ -0,0 +1,31 @@
+//
+// NopSCADlib Copyright Chris Palmer 2021
+// 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/bldc_motors.scad>
+
+module bldc_motors()
+    layout([for(b = bldc_motors) BLDC_diameter(b)])
+        rotate(-90)
+            BLDC(bldc_motors[$i]);
+
+if($preview)
+    let($show_threads = 1)
+        bldc_motors();

tests/BOM.scad

@@ -20,10 +20,10 @@
 //
 //! BOM and assembly demonstration
 //
+$explode = 1; // Normally set on the command line when generating assembly views with views.py
 include <../core.scad>
 include <../vitamins/sheets.scad>
 use <../vitamins/insert.scad>
-$explode = 1; // Normally set on the command line when generating assembly views with views.py
 
 screw = M3_cap_screw;
 sheet = PMMA3;

tests/LDRs.scad

@@ -16,6 +16,7 @@
 // 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/ldrs.scad>
 
 use <../utils/layout.scad>

tests/PCB.scad

@@ -64,21 +64,25 @@ test_pcb = ["TestPCB", "Test PCB",
         [ 16,  2,   90, "smd_res", RES1206, "1K"],
         [ 19,  2,   90, "smd_res", RES0805, "1K"],
         [ 22,  2,   90, "smd_res", RES0603, "1K"],
+        [ 25,  2,   90, "smd_cap", CAP1206, 1.5],
+        [ 28,  2,   90, "smd_cap", CAP0805, 1.0],
+        [ 31,  2,   90, "smd_cap", CAP0603, 0.7],
+
         [ 10,  10,   0, "2p54header", 4, 1],
         [ 25,  10,   0, "2p54header", 5, 1, false, "blue" ],
         [ 10,  20,   0, "2p54boxhdr", 4, 2],
         [ 10,  30,   0, "2p54socket", 6, 1],
         [ 25,  30,   0, "2p54socket", 4, 1, false, 0, false, "red" ],
-        [ 10,  40,   0, "chip", 10, 5, 1, grey(20)],
-        [  5,  50,   0, "led", LED3mm, "red"],
-        [ 12,  50,   0, "led", LED5mm, "orange"],
-        [ 25,  50,   0, "led", LED10mm, "yellow"],
-        [ 10,  65, 180, "rj45"],
-        [  8,  85, 180, "usb_A"],
+        [ 65,  50,   0, "led", LED3mm, "red"],
+        [ 75,  50,   0, "led", LED5mm, "orange"],
+        [ 90,  50,   0, "led", LED10mm, "yellow"],
+        [ 10,  45, 180, "rj45"],
+        [  8,  65, 180, "usb_A"],
         [  8, 105, 180, "usb_Ax2"],
+        [  7,  85, 180, "molex_usb_Ax1"],
+        [ 8.5,125, 180, "molex_usb_Ax2"],
         [  3, 140, 180, "usb_uA"],
         [  8, 155, 180, "usb_B"],
-        [  8.5, 125, 180, "molex_usb_Ax2"],
         [ 25, 200,   0, "buzzer", 4.5, 8.5],
         [ 25, 218,   0, "buzzer"],
         [  8, 190, 180, "jack"],
@@ -127,6 +131,8 @@ test_pcb = ["TestPCB", "Test PCB",
         [ 52, 200,   0, "pcb", 11, TMC2130 ],
         [ 80, 200,   0, "pdip", 24, "27C32", true, inch(0.6) ],
         [ 80, 170,   0, "pdip", 8, "NE555" ],
+        [ 80, 150,   0, "chip", 10, 5, 1, grey(20)],
+
         [ 52, 206,   0, "2p54socket", 8, 1 ],
         [ 52, 194,   0, "2p54socket", 8, 1, false, 0, false, "red" ],
         [ 50, 220,   0, "standoff",  5, 4.5, 12.5, 2.54],

tests/PCBs.scad

@@ -29,6 +29,11 @@ module pcbs() {
             rotate(90)
                 pcb_assembly(pcbs[$i], 5 + $i, 3);
 
+    translate([0, 45])
+        layout([for(p = tiny_pcbs) pcb_length(p)], 3)
+            translate([0, pcb_width(tiny_pcbs[$i]) / 2])
+                 pcb_assembly(tiny_pcbs[$i], 5 + $i, 3);
+
     translate([0, 120])
         layout([for(p = perfboards) pcb_length(p)], 10)
             translate([0, -pcb_width(perfboards[$i]) / 2])

tests/SMDs.scad

@@ -28,6 +28,11 @@ module smds() {
     translate([0, 3])
         layout([for(l = smd_leds) smd_led_size(l).x], 1)
             smd_led(smd_leds[$i], ["green", "blue", "red"][$i % 3]);
+
+    translate([0, 6])
+        layout([for(c = smd_capacitors) smd_cap_size(c).x], 1)
+            let(c = smd_capacitors[$i])
+                smd_capacitor(c, smd_cap_size(c).y * 0.8);
 }
 
 if($preview)

tests/ball_bearings.scad

@@ -16,7 +16,7 @@
 // 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/ball_bearings.scad>

tests/bearing_blocks.scad

@@ -17,7 +17,7 @@
 // If not, see <https://www.gnu.org/licenses/>.
 //
 include <../core.scad>
-include <../vitamins/scs_bearing_blocks.scad>
+include <../vitamins/bearing_blocks.scad>
 
 use <../utils/layout.scad>
 

tests/belts.scad

@@ -25,9 +25,9 @@ use <../utils/layout.scad>
 module belt_test() {
     p2 = [-75, -50];
     p3 = [-75, 100];
-    p4 = [75,  100];
+    p4 = [ 75, 100];
 
-    p5 = [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)];
 
     module pulleys(flip = false) {
@@ -52,19 +52,21 @@ module belt_test() {
         translate(p6) pulley_assembly(GT2x16_plain_idler);
     }
 
-    path = [ [p5.x, p5.y, pulley_pr(GT2x16_plain_idler)],
+    path = [ [-40,  0, 0],
              [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)]
+             [p4.x, p4.y, pulley_pr(GT2x20ob_pulley)],
+             [p5.x, p5.y, pulley_pr(GT2x16_plain_idler)],
+             [40,   0, 0],
            ];
 
     belt = GT2x6;
-    belt(belt, path, 80, [0,  0]);
+    belt(belt, path, open = true);
     pulleys();
     translate_z(20)
         hflip() {
-            belt(belt, path, 80, [0,  0], belt_colour = grey(90), tooth_colour = grey(50));
+            belt(belt, path, open = true, belt_colour = grey(90), tooth_colour = grey(50));
             pulleys(flip=true);
         }
 
@@ -72,6 +74,31 @@ module belt_test() {
         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));
+
+    // new example with open loop - this is a simplified example of the style used for example for the BLV 3D printer
+    pulley = GT2x20ob_pulley;
+    idler = GT2x16_plain_idler;
+    corners = [[-75,-50],[75,100]];
+    carriagepos = [0,0];
+    carriagew = 80;
+
+    points = [
+        [carriagepos.x - carriagew / 2, carriagepos.y, 0],
+        [corners[0].x + belt_pulley_pr(belt, pulley) + belt_pulley_pr(belt, idler), carriagepos.y - belt_pulley_pr(belt, idler), idler],
+        [corners[0].x, corners[0].y, pulley],
+        [corners[0].x, corners[1].y, idler],
+        [corners[1].x, corners[1].y, idler],
+        [corners[1].x, carriagepos.y + belt_pulley_pr(belt, idler), idler],
+        [carriagepos.x + carriagew / 2, carriagepos.y, 0]
+    ];
+    translate_z(-30) {
+        belt(belt, points, open=true, auto_twist=true);
+        for (p = points)
+            if (is_list(p.z))
+                translate([p.x, p.y, 0])
+                    pulley_assembly(p.z);
+    }
+
 }
 
 if($preview)

tests/box_sections.scad

@@ -0,0 +1,30 @@
+//
+// NopSCADlib Copyright Chris Palmer 2021
+// 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/layout.scad>
+
+include <../vitamins/box_sections.scad>
+
+module box_sections() {
+    layout([for(b = box_sections) box_section_size(b).x], 20)
+        box_section(box_sections[$i], 100);
+}
+
+if($preview)
+    box_sections();

tests/core_xy.scad

@@ -0,0 +1,134 @@
+//
+// 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>
+include <../vitamins/pulleys.scad>
+include <../vitamins/screws.scad>
+include <../vitamins/stepper_motors.scad>
+include <../vitamins/washers.scad>
+
+include <../utils/core_xy.scad>
+
+
+module coreXY_belts_test() {
+    coreXY_type = coreXY_GT2_20_16;
+    plain_idler = coreXY_plain_idler(coreXY_type);
+    toothed_idler = coreXY_toothed_idler(coreXY_type);
+
+    coreXYPosBL = [0, 0, 0];
+    coreXYPosTR = [200, 150, 0];
+    separation = [0, coreXY_coincident_separation(coreXY_type).y, pulley_height(plain_idler) + washer_thickness(M3_washer)];
+    pos = [100, 50];
+
+    upper_drive_pulley_offset = [40, 10];
+    lower_drive_pulley_offset = [0, 0];
+
+    coreXY_belts(coreXY_type,
+        carriagePosition = pos,
+        coreXYPosBL = coreXYPosBL,
+        coreXYPosTR = coreXYPosTR,
+        separation = separation,
+        x_gap = 10,
+        upper_drive_pulley_offset = upper_drive_pulley_offset,
+        lower_drive_pulley_offset = lower_drive_pulley_offset,
+        show_pulleys = true);
+
+
+    translate([coreXYPosBL.x + separation.x/2, coreXYPosTR.y + upper_drive_pulley_offset.y, separation.z/2]) {
+        // add the upper drive pulley stepper motor
+        translate([coreXY_drive_pulley_x_alignment(coreXY_type) + upper_drive_pulley_offset.x, 0, -pulley_height(coreXY_drive_pulley(coreXY_type))])
+            NEMA(NEMA17M);
+
+        // add the screws for the upper drive offset idler pulleys if required
+        if (upper_drive_pulley_offset.x > 0) {
+            translate(coreXY_drive_plain_idler_offset(coreXY_type))
+                translate_z(-pulley_offset(plain_idler))
+                    screw(M3_cap_screw, 20);
+            translate(coreXY_drive_toothed_idler_offset(coreXY_type))
+                translate_z(-pulley_offset(toothed_idler))
+                    screw(M3_cap_screw, 20);
+         } else if (upper_drive_pulley_offset.x < 0) {
+            translate([-pulley_od(plain_idler), coreXY_drive_plain_idler_offset(coreXY_type).y])
+                translate_z(-pulley_offset(plain_idler))
+                    screw(M3_cap_screw, 20);
+            translate([2*coreXY_drive_pulley_x_alignment(coreXY_type), coreXY_drive_toothed_idler_offset(coreXY_type).y])
+                translate_z(-pulley_offset(toothed_idler))
+                    screw(M3_cap_screw, 20);
+        }
+    }
+
+    translate([coreXYPosTR.x - separation.x/2, coreXYPosTR.y + lower_drive_pulley_offset.y, -separation.z/2]) {
+        // add the lower drive pulley stepper motor
+        translate([-coreXY_drive_pulley_x_alignment(coreXY_type) + lower_drive_pulley_offset.x, 0, -pulley_height(coreXY_drive_pulley(coreXY_type))])
+            NEMA(NEMA17M);
+
+        // add the screws for the lower drive offset idler pulleys if required
+        if (lower_drive_pulley_offset.x < 0) {
+            translate([-coreXY_drive_plain_idler_offset(coreXY_type).x, coreXY_drive_plain_idler_offset(coreXY_type).y])
+                translate_z(-pulley_offset(plain_idler))
+                    screw(M3_cap_screw, 20);
+            translate(coreXY_drive_toothed_idler_offset(coreXY_type))
+                translate_z(-pulley_offset(toothed_idler))
+                    screw(M3_cap_screw, 20);
+        } else if (lower_drive_pulley_offset.x > 0) {
+            translate([pulley_od(plain_idler), coreXY_drive_plain_idler_offset(coreXY_type).y])
+                translate_z(-pulley_offset(plain_idler))
+                    screw(M3_cap_screw, 20);
+            translate([-2*coreXY_drive_pulley_x_alignment(coreXY_type), coreXY_drive_toothed_idler_offset(coreXY_type).y])
+                translate_z(-pulley_offset(toothed_idler))
+                    screw(M3_cap_screw, 20);
+        }
+    }
+
+    // add the screw for the left upper idler pulley
+    translate([coreXYPosBL.x + separation.x/2, coreXYPosBL.y, separation.z])
+        screw(M3_cap_screw, 20);
+
+    // add the screw for the right upper idler pulley
+    translate([coreXYPosTR.x + separation.x/2, coreXYPosBL.y, separation.z])
+        screw(M3_cap_screw, 20);
+
+    if (separation.x != 0) {
+        // add the screw for the left lower idler pulley
+        translate([coreXYPosBL.x - separation.x/2, coreXYPosBL.y, 0])
+            screw(M3_cap_screw, 20);
+
+        // add the screw for the right lower idler pulley
+        translate([coreXYPosTR.x - separation.x/2, coreXYPosBL.y, 0])
+            screw(M3_cap_screw, 20);
+    }
+
+    translate([-separation.x/2, pos.y + coreXYPosBL.y -separation.y/2, -separation.z/2 + pulley_height(plain_idler)/2]) {
+        // add the screw for the left Y carriage toothed idler
+        translate([coreXYPosBL.x, coreXY_toothed_idler_offset(coreXY_type).y, 0])
+            screw(M3_cap_screw, 20);
+        // add the screw for the left Y carriage plain idler
+        translate([coreXYPosBL.x + separation.x + coreXY_plain_idler_offset(coreXY_type).x, separation.y + coreXY_plain_idler_offset(coreXY_type).y, separation.z])
+            screw(M3_cap_screw, 20);
+        // add the screw for the right Y carriage toothed idler
+        translate([coreXYPosTR.x + separation.x, coreXY_toothed_idler_offset(coreXY_type).y, separation.z])
+            screw(M3_cap_screw, 20);
+        // add the screw for the right Y carriage plain idler
+        translate([coreXYPosTR.x - coreXY_plain_idler_offset(coreXY_type).x, separation.y + coreXY_plain_idler_offset(coreXY_type).y, 0])
+            screw(M3_cap_screw, 20);
+    }
+}
+
+if ($preview)
+    coreXY_belts_test();

tests/displays.scad

@@ -16,6 +16,7 @@
 // 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/displays.scad>

tests/geared_steppers.scad

@@ -16,12 +16,13 @@
 // 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/geared_steppers.scad>
 
 use <../utils/layout.scad>
 
 module geared_steppers()
-    layout([for(g = geared_steppers) gs_diameter(g)], 5)
+    layout([for(g = geared_steppers) max(gs_diameter(g), gs_pitch(g) + gs_lug_w(g) / 2)], 5)
         geared_stepper(geared_steppers[$i]);
 
 geared_steppers();

tests/green_terminals.scad

@@ -16,6 +16,7 @@
 // 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/green_terminals.scad>

tests/hygrometer.scad

@@ -16,6 +16,7 @@
 // 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 <../vitamins/hygrometer.scad>
 
 if($preview)

tests/microview.scad

@@ -16,6 +16,7 @@
 // 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 <../vitamins/microview.scad>
 
 microview(!$preview);

tests/o_ring.scad

@@ -16,6 +16,7 @@
 // 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 <../vitamins/o_ring.scad>
 
 module o_rings()

tests/pillow_blocks.scad

@@ -17,7 +17,7 @@
 // If not, see <https://www.gnu.org/licenses/>.
 //
 include <../core.scad>
-include <../vitamins/kp_pillow_blocks.scad>
+include <../vitamins/pillow_blocks.scad>
 
 use <../utils/layout.scad>
 

tests/pocket_handle.scad

@@ -0,0 +1,40 @@
+//
+// NopSCADlib Copyright Chris Palmer 2021
+// 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/sheets.scad>
+
+use <../printed/pocket_handle.scad>
+
+show_holes = false;
+
+handle = pocket_handle();
+
+module pocket_handles() {
+    if($preview) {
+        pocket_handle_assembly(handle);
+
+        if(show_holes)
+            #pocket_handle_holes(handle);
+    }
+    else
+        pocket_handle(handle);
+}
+
+pocket_handles();

tests/press_fit.scad

@@ -16,8 +16,8 @@
 // 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>
+include <../core.scad>
+use <../printed/press_fit.scad>
 
 module press_fits()
 {

tests/rails.scad

@@ -22,21 +22,28 @@ include <../vitamins/rails.scad>
 use <../utils/layout.scad>
 use <../vitamins/nut.scad>
 
+length = 200;
 sheet = 3;
 pos = 1; //[-1 : 0.1 : 1]
 
+function rail_carriages(rail) = [for(c = carriages) if(carriage_rail(c) == rail) c];
+
 module rails()
-    layout([for(l = carriages) carriage_width(l)], 20)
+    layout([for(r = rails) carriage_width(rail_carriages(r)[0])], 20)
         rotate(-90) {
-            carriage = carriages[$i];
-            rail = carriage_rail(carriage);
-            length = 200;
+            rail = rails[$i];
+            carriages = rail_carriages(rail);
+            carriage = carriages[0];
             screw = rail_screw(rail);
             nut = screw_nut(screw);
             washer = screw_washer(screw);
 
             rail_assembly(carriage, length, pos * carriage_travel(carriage, length) / 2, $i<2 ? grey(20) : "green", $i<2 ? grey(20) : "red");
 
+            if(len(carriages) > 1)
+                translate([-carriage_travel(carriages[1], length) / 2, 0])
+                    carriage(carriages[1]);
+
             rail_screws(rail, length, sheet + nut_thickness(nut, true) + washer_thickness(washer));
 
             rail_hole_positions(rail, length, 0)

tests/rounded_triangle.scad

@@ -18,7 +18,7 @@
 //
 
 include <../global_defs.scad>
-use <../utils/rounded_right_triangle.scad>
+use <../utils/rounded_triangle.scad>
 
 
 module rounded_right_triangles() {

tests/screws.scad

@@ -16,6 +16,10 @@
 // You should have received a copy of the GNU General Public License along with NopSCADlib.
 // If not, see <https://www.gnu.org/licenses/>.
 //
+
+// Extra countersink depth
+sink = 0; // [0 : 0.05: 1.0]
+
 include <../core.scad>
 
 module polysink_stl() {
@@ -32,9 +36,9 @@ module polysink_stl() {
             let(s = cs_screws[i])
                 translate([i * 20, 0]) {
                     translate_z(size.z)
-                        screw_polysink(s, 2 * size.z + 1);
+                        screw_polysink(s, 2 * size.z + 1, sink = sink);
 
-                    screw_polysink(s, 2 * size.z + 1, alt = true);
+                    screw_polysink(s, 2 * size.z + 1, alt = true, sink = sink);
                 }
     }
 }

tests/sheets.scad

@@ -25,25 +25,30 @@ include <../vitamins/screws.scad>
 width = 30;
 2d = true;
 
-module sheets()
-    layout([for(s = sheets) width], 5)
-        let(sheet = sheets[$i], w = sheet_is_woven(sheet) ? width : undef)
-        if(2d)
-            render_2D_sheet(sheet, w = w, d = w)
-                difference() {
-                    sheet_2D(sheet, width, width, 2);
+module sheets() {
+    rows = 2;
+    n = ceil(len(sheets) / rows);
+    w = width + 5;
+    for(y = [0 : rows - 1], x = [0 : n - 1], s = y * n + x)
+        if(s < len(sheets))
+            translate([width / 2 + x * w, y * w])
+                let(sheet = sheets[s], w = sheet_is_woven(sheet) ? width : undef)
+                if(2d)
+                    render_2D_sheet(sheet, w = w, d = w)
+                        difference() {
+                            sheet_2D(sheet, width, width, 2);
 
-                    circle(3);
-                }
-        else
-            render_sheet(sheet, w = w, d = w)
-                difference() {
-                    sheet(sheet, width, width, 2);
-
-                    translate_z(sheet_thickness(sheet) / 2)
-                        screw_countersink(M3_cs_cap_screw);
-                }
+                            circle(3);
+                        }
+                else
+                    render_sheet(sheet, w = w, d = w)
+                        difference() {
+                            sheet(sheet, width, width, 2);
 
+                            translate_z(sheet_thickness(sheet) / 2)
+                                screw_countersink(M3_cs_cap_screw);
+                        }
+}
 
 if($preview)
     sheets();

utils/core/bom.scad

@@ -29,19 +29,24 @@
 //! This is to prevent the global BOM page becoming too wide in large projects by having it include just the major assemblies.
 //!
 //! The example below shows how to define a vitamin and incorporate it into an assembly with sub-assemblies and make an exploded view.
-//! The resulting flat BOM is shown but heirachical BOMs are also generated for real projects.
+//! The resulting flat BOM is shown but hierarchical BOMs are also generated for real projects.
 //!
 //! If the code to make an STL or DXF is made a child of the `stl()` or `dxf()` module then the STL or DXF will be used in the assembly views generated by `views.py` instead of generating
 //! it with code.
 //! This can speed up the generation of the build instructions greatly but isn't compatible with STLs that include support structures.
+//!
+//! The `pose()` module allows assembly views in the readme to be posed differently to the default view in the GUI:
+//!
+//! * Setting the `exploded` parameter to `true` allows just the exploded version to be posed and setting to `false` allows just the assembled view to be posed, the default is both.
+//! * If the `d` parameter is set to specify the camera distance then the normal `viewall` and `autocenter` options are suppressed allowing a small section to be zoomed in to fill the view.
+//! * To get the parameter values make the GUI window square, pose the view with the mouse and then copy the viewport parameters from the Edit menu and paste them into the pose invocation.
+//! * Two `pose()` modules can be chained to allow different poses for exploded and assembled views.
 //
 function bom_mode(n = 1) = $_bom >= n && (is_undef($on_bom) || $on_bom);  //! Current BOM mode, 0 = none, 1 = printed and routed parts and assemblies, 2 includes vitamins as well
 function exploded() = is_undef($exploded_parent) ? $exploded : 0;   //! Returns the value of `$exploded` if it is defined, else `0`
 function show_supports() = !$preview || exploded();                 //! True if printed support material should be shown
 
 module no_explode() let($exploded_parent = true) children();        //! Prevent children being exploded
-module no_pose() let($posed = true) children();                     //! Force children not to be posed even if parent is
-
 module explode(d, explode_children = false, offset = [0,0,0]) {     //! Explode children by specified Z distance or vector `d`, option to explode grand children
     v = is_list(d) ? d : [0, 0, d];
     o = is_list(offset) ? offset : [0, 0, offset];
@@ -62,17 +67,29 @@ module explode(d, explode_children = false, offset = [0,0,0]) {     //! Explode
         children();
 }
 
-module pose(a = [55, 0, 25], t = [0, 0, 0], exploded = undef)       //! Pose an STL or assembly for rendering to png by specifying rotation `a` and translation `t`, `exploded = true for` just the exploded view or `false` for unexploded only.
-    if(is_undef($pose) || !is_undef($posed) || (!is_undef(exploded) && exploded != !!exploded()))
-        children();
-    else
-        let($posed = true) // only pose the top level
-            rotate([55, 0, 25])
-                rotate([-a.x, 0, 0])
-                    rotate([0, -a.y, 0])
-                        rotate([0, 0, -a.z])
-                            translate(-t)
-                                children();
+module no_pose() let($posed = true, $zoomed = undef) children();    //! Force children not to be posed even if parent is
+
+module pose(a = [55, 0, 25], t = [0, 0, 0], exploded = undef, d = undef)       //! Pose an STL or assembly for rendering to png by specifying rotation `a`, translation `t` and optionally `d`, `exploded = true for` just the exploded view or `false` for unexploded only.
+    let($zoomed = is_undef(d)
+            ? is_undef($zoomed)
+                ? undef
+                : $zoomed
+            : is_undef(exploded)
+                ? 3
+                : exploded
+                    ? 2
+                    : 1)
+        if(is_undef($pose) || !is_undef($posed) || (!is_undef(exploded) && exploded != !!exploded()))
+            children();
+        else
+            let($posed = true) // only pose the top level
+                rotate([55, 0, 25])
+                    translate_z(is_undef(d) ? 0 : 140 - d)
+                        rotate([-a.x, 0, 0])
+                            rotate([0, -a.y, 0])
+                                rotate([0, 0, -a.z])
+                                    translate(-t)
+                                        children();
 
 module pose_hflip(exploded = undef)       //! Pose an STL or assembly for rendering to png by flipping around the Y axis, `exploded = true for` just the exploded view or `false` for unexploded only.
     if(is_undef($pose) || !is_undef($posed) || (!is_undef(exploded) && exploded != !!exploded()))
@@ -93,7 +110,9 @@ module pose_vflip(exploded = undef)       //! Pose an STL or assembly for render
 
 module assembly(name, big = undef, ngb = false) {    //! Name an assembly that will appear on the BOM, there needs to a module named `<name>_assembly` to make it. `big` can force big or small assembly diagrams.
     if(bom_mode()) {
-        args = is_undef(big) && !ngb ? "" : str("(big=", big, ", ngb=", ngb, ")");
+        zoom = is_undef($zoomed) ? 0 : $zoomed;
+        arglist = str(arg(big, undef, "big"), arg(ngb, false, "ngb"), arg(zoom, 0, "zoomed"));
+        args = len(arglist) ? str("(", slice(arglist, 2), ")") : "";
         echo(str("~", name, "_assembly", args, "{"));
     }
     no_pose()
@@ -146,17 +165,11 @@ module dxf(name) {                      //! Name a dxf that will appear on the B
         }
 }
 
-module use_stl(name) {               //! Import an STL to make a build platter
-    stl(name);
-    path = is_undef($target) ? "/stls/" : str("/", $target, "/stls/");
-    import(str($cwd, path, name, ".stl"));
-}
+module use_stl(name)                //! Import an STL to make a build platter
+    assert(false);                  // Here for documentation only, real version in core.scad
 
-module use_dxf(name) {               //! Import a DXF to make a build panel
-    dxf(name);
-    path = is_undef($target) ? "/dxfs/" : str("/", $target, "/dxfs/");
-    import(str($cwd, path, name, ".dxf"));
-}
+module use_dxf(name)                //! Import a DXF to make a build panel
+    assert(false);                  // Here for documentation only, real version in core.scad
 
 function value_string(value) = is_string(value) ? str("\"", value, "\"") : str(value); //! Convert `value` to a string or quote it if it is already a string
 

utils/core/clip.scad

@@ -18,7 +18,7 @@
 //
 
 //
-//! Construct arbirarily large box to partition 3D space and clip objects, useful for creating cross sections to see the inside when debugging.
+//! Construct arbitrarily large box to partition 3D space and clip objects, useful for creating cross sections to see the inside when debugging.
 //!
 //! Original version by Doug Moen on the OpenSCAD forum
 //

utils/core/core.scad

@@ -25,3 +25,15 @@ include <../../global_defs.scad>
 // Global functions and modules
 //
 use <global.scad>
+
+module use_stl(name) {               //! Import an STL to make a build platter
+    stl(name);
+    path = is_undef($target) ? "../stls/" : str($cwd, "/", $target, "/stls/");
+    import(str(path, name, ".stl"));
+}
+
+module use_dxf(name) {               //! Import a DXF to make a build panel
+    dxf(name);
+    path = is_undef($target) ? "../dxfs/" : str($cwd, "/", $target, "/dxfs/");
+    import(str(path, name, ".dxf"));
+}

utils/core/polyholes.scad

@@ -28,25 +28,25 @@
 //! large increase in the number of facets.
 //! When set to 1 the polygons alternate each layer, when set higher the rotation takes `twist + 1` layers to repeat.
 //! A small additional rotation is added to make the polygon rotate one more side over the length of the hole to make it appear round when
-//! veiwed end on.
+//! viewed end on.
 //!
 //! When `twist` is set the resulting cylinder is extended by `eps` at each end so that the exact length of the hole can be used without
 //! leaving a scar on either surface.
 //
-function sides(r) = max(round(4 * r), 3);                                       //! Optimium number of sides for specified radius
-function corrected_radius(r, n = 0)   = r / cos(180 / (n ? n : sides(r)));      //! Adjusted radius to make flats lie on the circle
-function corrected_diameter(d, n = 0) = d / cos(180 / (n ? n : sides(d / 2)));  //! Adjusted diameter to make flats lie on the circle
+function sides(r, n = undef) = is_undef(n) ? max(round(4 * r), 3) : n ? max(n, 3) : r2sides(r); //! Optimum number of sides for specified radius
+function corrected_radius(r, n = undef)   = r / cos(180 / sides(r, n));                         //! Adjusted radius to make flats lie on the circle
+function corrected_diameter(d, n = undef) = 2 * corrected_radius(d / 2 , n);                    //! Adjusted diameter to make flats lie on the circle
 
-module poly_circle(r, sides = 0) { //! Make a circle adjusted to print the correct size
-    n = sides ? sides : sides(r);
-    circle(r = corrected_radius(r,n), $fn = n);
+module poly_circle(r, sides = undef) { //! Make a circle adjusted to print the correct size
+    n = sides(r, sides);
+    circle(r = corrected_radius(r, n), $fn = n);
 }
 
-module poly_cylinder(r, h, center = false, sides = 0, chamfer = false, twist = 0) {//! Make a cylinder adjusted to print the correct size
+module poly_cylinder(r, h, center = false, sides = undef, chamfer = false, twist = 0) {//! Make a cylinder adjusted to print the correct size
     if(twist) {
         slices = ceil(h / layer_height);
         twists = min(twist + 1, slices);
-        sides = sides ? sides : sides(r);
+        sides = sides(r, sides);
         rot = 360 / sides / twists * (twists < slices ? (1 + 1 / slices) : 1);
         if(center)
             for(side = [0, 1])
@@ -64,10 +64,10 @@ module poly_cylinder(r, h, center = false, sides = 0, chamfer = false, twist = 0
             poly_circle(r, sides);
 
     if(h && chamfer)
-        poly_cylinder(r + layer_height, center ? layer_height * 2 : layer_height, center, sides = sides ? sides : sides(r));
+        poly_cylinder(r + layer_height, center ? layer_height * 2 : layer_height, center, sides = sides(r, sides));
 }
 
-module poly_ring(or, ir, sides = 0) { //! Make a 2D ring adjusted to have the correct internal radius
+module poly_ring(or, ir, sides = undef) { //! Make a 2D ring adjusted to have the correct internal radius
     cir = corrected_radius(ir, sides);
     filaments = (or - cir) / extrusion_width;
     if(filaments > 3 + eps)

utils/core/teardrops.scad

@@ -26,7 +26,7 @@
 //
 module teardrop(h, r, center = true, truncate = true, chamfer = 0, chamfer_both_ends = true, 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) {
-        er = layer_height / 2 - eps;    // Extrustion edge radius
+        er = layer_height / 2 - eps;    // Extrusion edge radius
         R = plus ? r + er : r;          // Corrected radius
         offset = plus ? -er : 0;        // Offset inwards
         hull()

utils/core_xy.scad

@@ -0,0 +1,204 @@
+//
+// 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/>.
+//
+
+//
+//! Parameterised Core XY implementation. Draws the belts and provides utilities for positioning the pulleys.
+//!
+//! The belts are positioned according the bottom left "anchor" pulley and the top right drive pulley.
+//! Implementation has the following features:
+//!
+//! 1. The drive and idler pulleys may be different sizes.
+//! 2. The belt separation is parameterised.
+//! 3. The separation of the plain and toothed pulleys on the Y carriages is parameterised, in both the X and the Y direction.
+//! 4. The drive pulleys may be offset in the X and Y directions. If this is done, extra idler pulleys are added. This
+//! allows flexible positioning of the motors.
+//
+include <../core.scad>
+include <../vitamins/belts.scad>
+include <../vitamins/pulleys.scad>
+
+
+coreXY_GT2_20_20 = ["coreXY_20_20", GT2x6, GT2x20ob_pulley, GT2x20_toothed_idler, GT2x20_plain_idler, [0, 0, 1], [0, 0, 0.5, 1], [0, 1, 0], [0, 0.5, 0, 1] ];
+coreXY_GT2_20_16 = ["coreXY_20_16", GT2x6, GT2x20ob_pulley, GT2x16_toothed_idler, GT2x16_plain_idler, [0, 0, 1], [0, 0, 0.5, 1], [0, 1, 0], [0, 0.5, 0, 1] ];
+coreXY_GT2_16_16 = ["coreXY_16_16", GT2x6, GT2x16_pulley,   GT2x16_toothed_idler, GT2x16_plain_idler, [0, 0, 1], [0, 0, 0.5, 1], [0, 1, 0], [0, 0.5, 0, 1] ];
+
+function coreXY_belt(type)                  = type[1]; //! Belt type
+function coreXY_drive_pulley(type)          = type[2]; //! Drive pulley type
+function coreXY_toothed_idler(type)         = type[3]; //! Toothed idler type
+function coreXY_plain_idler(type)           = type[4]; //! Plain idler type
+function coreXY_upper_belt_colour(type)     = type[5]; //! Colour of the upper belt
+function coreXY_upper_tooth_colour(type)    = type[6]; //! Colour of the upper belt's teeth
+function coreXY_lower_belt_colour(type)     = type[7]; //! Colour of the lower belt
+function coreXY_lower_tooth_colour(type)    = type[8]; //! Colour of the lower belt's teeth
+
+// used to offset the position of the drive pulley and the y-carriage plain idler pulley
+// relative to the anchor pulley so that the belts align properly
+function coreXY_drive_pulley_x_alignment(type) = //! Belt alignment offset of the drive pulley relative to the anchor pulley
+    (pulley_od(coreXY_drive_pulley(type)) - pulley_od(coreXY_toothed_idler(type))) / 2;
+
+function coreXY_coincident_separation(type) = //! Value of x, y separation to make y-carriage pulleys coincident
+    [ -coreXY_plain_idler_offset(type).x, -(pulley_od(coreXY_plain_idler(type)) + pulley_od(coreXY_toothed_idler(type)))/2, 0 ];
+
+function coreXY_plain_idler_offset(type)    = //! Offset of y-carriage plain idler
+    [ (pulley_od(coreXY_plain_idler(type)) + pulley_od(coreXY_drive_pulley(type))) / 2 + coreXY_drive_pulley_x_alignment(type), pulley_od(coreXY_plain_idler(type))/2, 0 ];
+
+function coreXY_toothed_idler_offset(type)  = //! offset of y-carriage toothed idler
+    [ 0, -pulley_pr(coreXY_toothed_idler(type)), 0 ];
+
+// helper functions for positioning idlers when the stepper motor drive pulley is offset
+function coreXY_drive_toothed_idler_offset(type) = //! Offset of toothed drive idler pulley
+    [ 0, coreXY_drive_pulley_x_alignment(type), 0 ];
+
+function coreXY_drive_plain_idler_offset(type) = //! Offset of plain drive idler pulley
+    [ coreXY_plain_idler_offset(type).x, -(pulley_od(coreXY_plain_idler(type)) + pulley_od(coreXY_drive_pulley(type))) / 2, 0 ];
+
+
+module coreXY_half(type, size, pos, separation_y = 0, x_gap = 0, plain_idler_offset = 0, drive_pulley_offset = [0, 0], show_pulleys = false, lower_belt = false, hflip = false) { //! Draw one belt of a coreXY setup
+
+    // y-carriage toothed pulley
+    p0_type = coreXY_toothed_idler(type);
+    p0 = [ size.x / 2, -size.y / 2 - pulley_od(p0_type) / 2 + pos.y - separation_y / 2 ];
+
+    // bottom right toothed idler pulley
+    p1_type = p0_type;
+    p1 = [ size.x / 2, -size.y / 2 ];
+
+    // bottom left anchor toothed idler pulley
+    p2_type = p0_type;
+    p2 = [ -size.x / 2, -size.y / 2 ];
+
+    // stepper motor drive pulley
+    p3d_type = coreXY_drive_pulley(type);
+    p3d = [ -size.x / 2 + coreXY_drive_pulley_x_alignment(type) + drive_pulley_offset.x,
+             size.y / 2 + drive_pulley_offset.y
+    ];
+
+    // toothed idler for offset stepper motor drive pulley
+    p3t_type = coreXY_toothed_idler(type);
+    p3t = [ -size.x / 2 + (drive_pulley_offset.x > 0 ? 0 : 2 * coreXY_drive_pulley_x_alignment(type)),
+            size.y / 2 + coreXY_drive_pulley_x_alignment(type) + drive_pulley_offset.y
+    ];
+
+    // y-carriage plain pulley
+    p4_type = coreXY_plain_idler(type);
+    p4 = [ -size.x / 2 + pulley_od(p4_type) / 2 + pulley_od(p3d_type) / 2 + coreXY_drive_pulley_x_alignment(type) + plain_idler_offset,
+           -size.y / 2 + pulley_od(p4_type) / 2 + pos.y + separation_y / 2
+    ];
+
+    // plain idler for offset stepper motor drive pulley
+    p3p_type = p4_type;
+    p3p = [ drive_pulley_offset.x > 0 ? p4.x : -p0.x - pulley_od(p0_type),
+            size.y / 2 - pulley_od(p3p_type) / 2 - pulley_od(p3d_type) / 2 + drive_pulley_offset.y
+    ];
+
+    // Start and end points
+    start_p = [ pos.x - size.x / 2 + x_gap / 2, -size.y / 2 + pos.y - separation_y / 2, 0 ];
+    end_p   = [ pos.x - size.x / 2 - x_gap / 2, -size.y / 2 + pos.y + separation_y / 2, 0 ];
+
+    //p6_type = p0_type;
+
+    module show_pulleys(show_pulleys) {// Allows the pulley colour to be set for debugging
+        if (is_list(show_pulleys))
+            color(show_pulleys)
+                children();
+        else if (show_pulleys)
+            children();
+    }
+
+    show_pulleys(show_pulleys) {
+        translate(p0)
+            pulley_assembly(p0_type); // y-carriage toothed pulley
+
+        translate(p1)
+            pulley_assembly(p1_type); // bottom right toothed idler pulley
+
+        translate(p2)
+            pulley_assembly(p2_type); // bottom left anchor toothed idler pulley
+
+        translate(p3d)
+            hflip(hflip)
+                pulley_assembly(p3d_type); // top left stepper motor drive pulley
+
+        if (drive_pulley_offset.x) { // idler pulleys for offset stepper motor drive pulley
+            translate(p3t)
+                pulley_assembly(p3t_type); // toothed idler
+
+            translate(p3p)
+                pulley_assembly(p3p_type); // plain idler
+        }
+        translate(p4)
+            pulley_assembly(p4_type); // y-carriage plain pulley
+    }
+
+    path0a = [
+        [ p0.x, p0.y, pulley_od(p0_type) / 2 ],
+        [ p1.x, p1.y, pulley_od(p1_type) / 2 ],
+        [ p2.x, p2.y, pulley_od(p2_type) / 2 ]
+    ];
+    path0b = [
+        [ p3d.x, p3d.y, pulley_od(p3d_type) / 2 ],
+        [ p4.x, p4.y, -pulley_od(p4_type) / 2 ]
+    ];
+    path0c = [
+        [ p3t.x, p3t.y, pulley_od(p3t_type) / 2 ],
+        [ p3d.x, p3d.y, pulley_od(p3d_type) / 2 ],
+        [ p3p.x, p3p.y, -pulley_od(p3p_type) / 2 ],
+        [ p4.x, p4.y, -pulley_od(p4_type) / 2 ]
+    ];
+    path0d = [
+        [ p3p.x, p3p.y, -pulley_od(p3p_type) / 2 ],
+        [ p3d.x, p3d.y, pulley_od(p3d_type) / 2 ],
+        [ p3t.x, p3t.y, pulley_od(p3t_type) / 2 ],
+        [ p4.x, p4.y, -pulley_od(p4_type) / 2 ]
+    ];
+
+    belt = coreXY_belt(type);
+
+    path0 = drive_pulley_offset.x == 0 ? concat(path0a, path0b) : drive_pulley_offset.x > 0 ? concat(path0a, path0c) : concat(path0a, path0d);
+    path = concat([start_p], path0, [end_p]);
+
+    belt(type = belt,
+        points = path,
+        open = true,
+        belt_colour  = lower_belt ? coreXY_lower_belt_colour(type) : coreXY_upper_belt_colour(type),
+        tooth_colour = lower_belt ? coreXY_lower_tooth_colour(type) : coreXY_upper_tooth_colour(type));
+}
+
+module coreXY(type, size, pos, separation, x_gap, plain_idler_offset = 0, upper_drive_pulley_offset, lower_drive_pulley_offset, show_pulleys = false, left_lower = false) { //! Wrapper module to draw both belts of a coreXY setup
+    translate([size.x / 2 - separation.x / 2, size.y / 2, -separation.z / 2]) {
+        // lower belt
+        hflip(!left_lower)
+            explode(25)
+                coreXY_half(type, size, [size.x - pos.x - separation.x/2 - (left_lower ? x_gap : 0), pos.y], separation.y, x_gap, plain_idler_offset, [-lower_drive_pulley_offset.x, lower_drive_pulley_offset.y], show_pulleys, lower_belt = true, hflip = true);
+
+        // upper belt
+        translate([separation.x, 0, separation.z])
+            hflip(left_lower)
+                explode(25)
+                    coreXY_half(type, size, [pos.x + separation.x/2 + (left_lower ? x_gap : 0), pos.y], separation.y, x_gap, plain_idler_offset, upper_drive_pulley_offset, show_pulleys, lower_belt = false, hflip = false);
+    }
+}
+
+module coreXY_belts(type, carriagePosition, coreXYPosBL, coreXYPosTR, separation, x_gap = 20, upper_drive_pulley_offset = [0, 0], lower_drive_pulley_offset = [0, 0], show_pulleys = false, left_lower = false) { //! Draw the coreXY belts
+    assert(coreXYPosBL.z == coreXYPosTR.z);
+
+    coreXYSize = coreXYPosTR - coreXYPosBL;
+    translate(coreXYPosBL)
+        coreXY(type, coreXYSize, [carriagePosition.x - coreXYPosBL.x, carriagePosition.y - coreXYPosBL.y], separation = separation, x_gap = x_gap, plain_idler_offset = 0, upper_drive_pulley_offset = upper_drive_pulley_offset, lower_drive_pulley_offset = lower_drive_pulley_offset, show_pulleys = show_pulleys, left_lower = left_lower);
+}

utils/gears.scad

@@ -135,4 +135,4 @@ function involute_worm_profile(m, pa = 20, clearance = undef) = //! Calculate wo
     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
+    ) [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 coordinate

utils/maths.scad

@@ -88,6 +88,7 @@ function scale(v) = let(s = is_list(v) ? v : [v, v, v]) //!  Generate a 4x4 matr
                           [0,   0,   0,   1]
                         ];
 
+function vec2(v) = [v.x, v.y]; //! Return a 2 vector with the first two elements of `v`
 function vec3(v) = [v.x, v.y, v.z]; //! Return a 3 vector with the first three elements of `v`
 function vec4(v) = [v.x, v.y, v.z, 1]; //! Return a 4 vector with the first three elements of `v`
 function transform(v, m) = vec3(m * [v.x, v.y, v.z, 1]); //! Apply 4x4 transform to a 3 vector by extending it and cropping it again
@@ -153,3 +154,36 @@ function circle_intersect(c1, r1, c2, r2) =     //! Calculate one point where tw
         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
+
+function map(v, func) = [ for (e = v) func(e) ]; //! make a new vector where the func function argument is applied to each element of the vector v
+function mapi(v, func) = [ for (i = [0:len(v)-1]) func(i,v[i]) ]; //! make a new vector where the func function argument is applied to each element of the vector v. The func will get the index number as first argument, and the element as second argument.
+function reduce(v, func, unity) = let ( r = function(i,val) i == len(v) ? val : r(i + 1, func(val, v[i])) ) r(0, unity); //! reduce a vector v to a single entity by applying the func function recursively to the reduced value so far and the next element, starting with unity as the initial reduced value
+function sumv(v) = reduce(v, function(a, b) a + b, 0); //! sum a vector of values that can be added with "+"
+
+function xor(a,b) = (a && !b) || (!a && b);     //! Logical exclusive OR
+function cuberoot(x)= sign(x)*abs(x)^(1/3);
+
+function quadratic_real_roots(a, b, c) =        //! Returns real roots of a quadratic equation, biggest first. Returns empty list if no real roots
+    let(2a = 2 * a,
+        2c = 2 * c,
+        det = b^2 - 2a * 2c
+    ) det < 0 ? [] :
+        let(r = sqrt(det),
+            x1 = b < 0 ? 2c / (-b + r) : (-b - r) / 2a,
+            x2 = b < 0 ? (-b + r) / 2a : 2c / (-b - r)
+        ) [x2, x1];
+
+function cubic_real_roots(a, b, c, d) = //! Returns real roots of cubic equation
+    let(b = b / a,
+        c = c / a,
+        d = d / a,
+        inflection = -b / 3,
+        p = c - b^2 / 3,
+        q = 2 * b^3 / 27 - b * c / 3 + d,
+        det = q^2 / 4 + p^3 / 27,
+        roots = !p && !q ? 1 : nearly_zero(det) ? 2 :  det < 0 ? 3 : 1,
+        r = sqrt(det),
+        x = cuberoot(-q / 2 - r) + cuberoot(-q / 2 + r)
+    ) roots == 1 ? [x] :
+      roots == 2 ? [3 * q /p + inflection, -3 * q / p / 2 + inflection] :
+      [for(i = [0 : roots - 1]) 2 * sqrt(-p / 3) * cos(acos(3 * q * sqrt(-3 / p) / p / 2) - i * 120) + inflection];

utils/rounded_polygon.scad

@@ -24,6 +24,7 @@
 //! Because the tangents need to be calculated to find the length these can be calculated separately and re-used when drawing to save calculating them twice.
 //
 include <../utils/core/core.scad>
+use <../utils/maths.scad>
 
 function circle_tangent(p1, p2) = //! Compute the clockwise tangent between two circles represented as [x,y,r]
     let(
@@ -36,56 +37,66 @@ function circle_tangent(p1, p2) = //! Compute the clockwise tangent between two
         v = [cos(theta), sin(theta)]
     )[ p1 + r1 * v, p2 + r2 * v ];
 
-function rounded_polygon_tangents(points) = //! Compute the straight sections needed to draw and to compute the lengths
-    let(len = len(points))
-        [for(i = [0 : len - 1])
-            let(ends = circle_tangent(points[i], points[(i + 1) % len]))
-                for(end = [0, 1])
-                    ends[end]];
+function rounded_polygon_arcs(points, tangents) = //! Compute the arcs at the points, for each point [angle, rotate_angle, length]
+    let(
+        len = len(points)
+    ) [ for (i = [0: len-1])
+        let(
+            p1 = vec2(tangents[(i - 1 + len) % len][1]),
+            p2 = vec2(tangents[i][0]),
+            p = vec2(points[i]),
+            v1 = p1 - p,
+            v2 = p2 - p,
+            sr = points[i][2],
+            r = abs(sr),
+            a = r < 0.001 ? 0 : let( aa = acos((v1 * v2) / sqr(r)) ) cross(v1, v2) * sign(sr) <= 0 ? aa : 360 - aa,
+            l = PI * a * r / 180,
+            v0 = [r, 0],
+            v = let (
+                vv = norm(v0 - v2) < 0.001 ? 0 : abs(v2.y) < 0.001 ? 180 :
+                        let( aa = acos((v0 * v2) / sqr(r)) ) cross(v0, v2) * sign(sr) <= 0 ? aa : 360 - aa
+            ) sr > 0 ? 360 - vv : vv - a
+        ) [a, v, l]
+    ];
 
-function sumv(v, i = 0, sum = 0) = i == len(v) ? sum : sumv(v, i + 1, sum + v[i]);
+function rounded_polygon_tangents(points) = //! Compute the straight sections between a point and the next point, for each section [start_point, end_point, length]
+    let(len = len(points))
+    [ for(i = [0 : len - 1])
+        let(ends = circle_tangent(points[i], points[(i + 1) % len]))
+            [ends[0], ends[1], norm(ends[0] - ends[1])]
+    ];
 
 // the cross product of 2D vectors is the area of the parallelogram between them. We use the sign of this to decide if the angle is bigger than 180.
 function rounded_polygon_length(points, tangents) = //! Calculate the length given the point list and the list of tangents computed by ` rounded_polygon_tangents`
     let(
-      len = len(points),
-      indices = [0 : len - 1],
-      straights = [for(i = indices) norm(tangents[2 * i] - tangents[2 * i + 1])],
-      arcs = [for(i = indices) let(p1 = tangents[2 * i + 1],
-                                   p2 = tangents[(2 * i + 2) % (2 * len)],
-                                   corner = points[(i + 1) % len],
-                                   c = [corner.x, corner.y],
-                                   v1 = p1 - c,
-                                   v2 = p2 - c,
-                                   r = abs(corner.z),
-                                   a = acos((v1 * v2) / sqr(r))) r ? PI * (cross(v1, v2) <= 0 ? a : 360 - a) * r / 180 : 0]
-     )
-    sumv(concat(straights, arcs));
+        arcs = rounded_polygon_arcs(points, tangents)
+    ) sumv( map( concat(tangents, arcs), function(e) e[2] ) );
 
 module rounded_polygon(points, _tangents = undef) { //! Draw the rounded polygon from the point list, can pass the tangent list to save it being calculated
     len = len(points);
     indices = [0 : len - 1];
     tangents = _tangents ? _tangents : rounded_polygon_tangents(points);
 
-    difference(convexity = points) {
+    difference() {
         union() {
-            for(i = indices)
+            for(i = indices, last = (i - 1 + len) % len)
                 if(points[i][2] > 0)
                     hull() {
-                        translate([points[i].x, points[i].y])
+                        translate(vec2(points[i]))
                             circle(points[i][2]);
-                        polygon([tangents[(2 * i - 1 + 2 * len) % (2 * len)], tangents[2 * i], [points[i].x, points[i].y]]);
+
+                        polygon([vec2(tangents[last][1]), vec2(tangents[i][0]), vec2(points[i])]);
                     }
 
-            polygon(tangents, convexity = points);
+            polygon([for(t = tangents) each(vec2(t))], convexity = points);
         }
-        for(i = indices)
+        for(i = indices, last = (i - 1 + len) % len)
             if(points[i][2] < 0)
                 hull() {
-                    translate([points[i].x, points[i].y])
+                    translate(vec2(points[i]))
                         circle(-points[i][2]);
 
-                    polygon([tangents[(2 * i - 1 + 2 * len) % (2 *len)], tangents[2 * i], [points[i].x, points[i].y]]);
+                    polygon([vec2(tangents[last][1]), vec2(tangents[i][0]), vec2(points[i])]);
                 }
      }
 }

utils/rounded_triangle.scad

@@ -21,7 +21,6 @@
 //! Draw a 3D right triangle with rounded edges. Intended to be embedded in other parts. Can be optionally offset by the filleted amount.
 //
 include <../utils/core/core.scad>
-include <..//utils/core/rounded_rectangle.scad>
 
 module rounded_right_triangle(x, y, z, fillet, center = true, offset = false) { //! Draw a 3D right triangle with rounded edges.
     fillet = max(fillet, eps);

utils/sweep.scad

@@ -18,7 +18,7 @@
 //
 
 //
-//! Utility to generate a polhedron by sweeping a 2D profile along a 3D path and utilities for generating paths.
+//! Utility to generate a polyhedron 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.
 //! Subsequent rotations use the minimum rotation method.

utils/thread.scad

@@ -50,6 +50,7 @@ function thread_profile(h, crest, angle, overlap = 0.1) = //! Create thread prof
         [[-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 female thread, ends can be tapered, chamfered or square
+    assert(is_undef(colour) || is_list(colour), "Thread colour must be in [r, g, b] form");
     //
     // Apply colour if defined
     //
@@ -155,7 +156,7 @@ module thread(dia, pitch, length, profile, center = true, top = -1, bot = -1, st
                                         translate([0, offset])
                                             square([r, len]);
 
-                                        translate([0, bot_chamfer_h])
+                                        translate([0, offset + bot_chamfer_h])
                                             square([r + h + overlap, len - top_chamfer_h - bot_chamfer_h]);
                                     }
                                     if(!solid)
@@ -190,7 +191,8 @@ module female_metric_thread(d, pitch, length, center = true, top = -1, bot = -1,
 }
 
 function metric_coarse_pitch(d) //! Convert metric diameter to pitch
-    = d == 1.6 ? 0.35  // M1.6
+    = d == 1.4 ? 0.3   // M1.4
+    : d == 1.6 ? 0.35  // M1.6
                : [0.4, // M2
                   0.45,// M2.5
                   0.5, // M3

utils/tube.scad

@@ -69,7 +69,7 @@ module woven_tube(or, ir, h, center= true, colour = grey(30), colour2, warp = 2,
     }
 }
 
-module rectangular_tube(size, center = true, thickness = 1, fillet = 0.5) { //! Create a retangular tube with filleted corners
+module rectangular_tube(size, center = true, thickness = 1, fillet = 0.5) { //! Create a rectangular tube with filleted corners
     extrude_if(size.z, center = center)
         difference() {
             rounded_square([size.x, size.y], fillet);

vitamins/bearing_blocks.scad

@@ -40,4 +40,4 @@ SCS16LUU  = ["SCS16LUU",  9, 19, 25, 50, 85, 38.5, 32.5, 36, 60, 7,    M5_cap_sc
 scs_bearing_blocks = [SCS6UU, SCS8UU,  SCS10UU, SCS12UU, SCS16UU];
 scs_bearing_blocks_long = [SCS8LUU,  SCS10LUU, SCS12LUU, SCS16LUU];
 
-use <scs_bearing_block.scad>
+use <bearing_block.scad>

vitamins/belt.scad

@@ -18,19 +18,29 @@
 //
 
 //
-//! Models timing belt running over toothed or smooth pulleys and calculates an accurate length.
-//! Only models 2D paths, so not crossed belt core XY!
+//! Models timing belt running in a path over toothed or smooth pulleys and calculates an accurate length.
+//! Only models 2D paths, belt may twist to support crossed belt core XY and other designs where the belt twists!
+//!
+//! By default the path is a closed loop. An open loop can be specified by specifying `open=true`, and in that case the start and end points are not connected, leaving the loop open.
+//!
+//! To get a 180 degree twist of the loop, you can use the `twist` argument. `Twist` can be a single number, and in that case the belt will twist after
+//! the position with that number. Alternatively `twist` can be a list of boolean values with a boolean for each position; the belt will then twist after
+//! the position that have a `true` value in the `twist` list. If the path is specified with pulley/idler types, then you can use `auto_twist=true`; in
+//! that case the belt will automatically twist so the back of the belt always runs against idlers and the tooth side runs against pulleys. If you use
+//! `open=true` then you might also use `start_twist=true` to let the belt start the part with the back side out.
+//!
+//! The path must be specified as a list of positions. Each position should be either a vector with `[x, y, pulley]` or `[x, y, r]`. A pulley is a type from
+//! `pulleys.scad`, and correct radius and angle will automatically be calculated. Alternatively a radius can be specified directly.
 //!
 //! 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.
+//! Alternatively you can just specify smooth pulleys in the path, and it will then happen automatically.
 //!
 //! 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>
+use <pulley.scad>
 
 function belt_pitch(type)        = type[1]; //! Pitch in mm
 function belt_width(type)        = type[2]; //! Width in mm
@@ -41,47 +51,102 @@ function belt_pitch_height(type) = type[5] + belt_tooth_height(type); //! Offset
 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_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
+module belt(type, points, belt_colour = grey(20), tooth_colour = grey(50), open = false, twist = undef, auto_twist = false, start_twist = false) { //! Draw a belt path given a set of points and pitch radii where the pulleys are. Closed loop unless open is specified
     width = belt_width(type);
     pitch = belt_pitch(type);
     thickness = belt_thickness(type);
+
+    info = _belt_points_info(type, points, open, twist, auto_twist, start_twist);
+    dotwist = info[0]; // array of booleans, true if a twist happen after the position
+    twisted = info[1]; // array of booleans, true if the belt is twisted at the position
+    pointsx = info[2]; // array of [x,y,r], r is negative if left-angle (points may have pulleys as third element, but pointsx have radii)
+    tangents = info[3];
+    arcs = info[4];
+    length = ceil(_belt_length(info, open) / pitch) * pitch;
+
     part = str(type[0],pitch);
-    vitamin(str("belt(", no_point(part), "x", width, ", ", points, arg(gap, 0), arg(gap_pos, undef), "): Belt ", part," x ", width, "mm x ", length, "mm"));
+    vitamin(str("belt(", no_point(part), "x", width, ", ", pointsx, "): Belt ", part," x ", width, "mm x ", length, "mm"));
 
     len = len(points);
 
-    tangents = rounded_polygon_tangents(points);
-
-    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_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);
+    ph = belt_pitch_height(type);
+    module beltp() translate([ph - th, -width / 2]) square([th, width]);
+    module beltb() translate([ph - thickness, -width / 2]) square([thickness - th, width]);
 
-    color(belt_colour)
-        linear_extrude(width, center = true)
-            difference() {
-                offset(-ph + thickness ) shape();
-                offset(-ph + th) shape();
-                gap();
-            }
+    for (i = [0 : len - (open ? 2 : 1)]) {
+        p1 = tangents[i].x;
+        p2 = tangents[i].y;
+        v = p2-p1;
+        a =  atan(v.y / v.x) - (v.x < 0 ? 180 : 0); //a2(p2-p1);
+        l = norm(v);
+        translate(p1) rotate([-90, 0, a - 90]) {
+            twist = dotwist[i] ? 180 : 0;
+            mirrored = twisted[i] ? 1 : 0;
+            color(tooth_colour) linear_extrude(l, twist = twist) mirror([mirrored, 0, 0]) beltp();
+            color(belt_colour)  linear_extrude(l, twist = twist) mirror([mirrored, 0, 0]) beltb();
+        }
+    }
 
-    color(tooth_colour)
-        linear_extrude(width, center = true)
-            difference() {
-                offset(-ph + th) shape();
-                offset(-ph) shape();
-                gap();
-            }
+    for (i = [(open ? 1 : 0) : len - (open ? 2 : 1)]) {
+        p = pointsx[i];
+        arc = arcs[i];
+        translate([p.x, p.y]) rotate([0, 0, arc[1]]) {
+            mirrored = xor(twisted[i], p[2] < 0) ? 0 : 1;
+            color(tooth_colour) rotate_extrude(angle = arc[0]) translate([abs(p[2]), 0, 0]) mirror([mirrored, 0, 0]) beltp();
+            color(belt_colour)  rotate_extrude(angle = arc[0]) translate([abs(p[2]), 0, 0]) mirror([mirrored, 0, 0]) beltb();
+        }
+    }
 }
 
-function belt_length(points, gap = 0) = rounded_polygon_length(points, rounded_polygon_tangents(points)) - gap; //! Compute belt length given path and optional gap
+function _belt_points_info(type, points, open, twist, auto_twist, start_twist) = //! Helper function that calculates [twist, istwisted, points, tangents, arcs]
+let(
+    len = len(points),
+    isleft = function(i) let(
+            p = vec2(points[i]),
+            p0 = vec2(points[(i - 1 + len) % len]),
+            p1 = vec2(points[(i + 1) % len])
+        ) cross(p-p0,p1-p) > 0,
+    dotwist = function(i, istwisted) let( in = (i + 1) % len )
+        is_list(twist) ? twist[i] :
+        !is_undef(twist) ? i == twist :
+        open && is_list(points[in][2]) && auto_twist ? !pulley_teeth(points[in][2]) && !xor(isleft(in), istwisted) :
+        false,
+    twisted = [
+        for (
+            i = 0,
+            istwisted = start_twist,
+            twist = dotwist(i, istwisted),
+            nexttwisted = xor(twist, istwisted);
+            i < len;
+            i = i + 1,
+            istwisted = nexttwisted,
+            twist = dotwist(i, istwisted),
+            nexttwisted = xor(twist, istwisted)
+        ) [twist, istwisted] ],
+    pointsx = mapi(points, function(i, p) !is_list(p[2]) ? p : [p.x, p.y, let( // if p[2] is not a list it is just r, otherwise it is taken to be a pulley and we calculate r
+            isleft = isleft(i),
+            r = belt_pulley_pr(type, p[2], twisted = !xor(pulley_teeth(p[2]), xor(isleft, twisted[i][1])))
+        ) isleft ? -r : r ] ),
+    tangents = rounded_polygon_tangents(pointsx),
+    arcs = rounded_polygon_arcs(pointsx, tangents)
+) [ [ for (t = twisted) t[0] ], [ for (t = twisted) t[1] ], pointsx, tangents, arcs];
+
+function belt_pulley_pr(type, pulley, twisted=false) = //! Pitch radius. Default it expects the belt tooth to be against a toothed pulley an the backside to be against a smooth pulley (an idler). If `twisted` is true, the the belt is the other way around.
+    let(
+        thickness = belt_thickness(type),
+        ph = belt_pitch_height(type)
+    ) pulley_teeth(pulley)
+        ? pulley_pr(pulley) + (twisted ? thickness - ph : 0 )
+        : pulley_ir(pulley) + (twisted ? ph : thickness - ph );
+
+
+function belt_length(type, points, open = false) = _belt_length(_belt_points_info(type, points, open), open); //! Compute belt length given path
+
+function _belt_length(info, open) = let(
+    len = len(info[0]),
+    d = open ? 1 : 0,
+    tangents = slice(info[3], 0, len - d) ,
+    arcs = slice(info[4], d, len - d)
+) sumv( map( concat(tangents, arcs), function(e) e[2] ));