Updated images and readme.

1. Better default parameters
2. Changed plain_idler_offset to work in x and y, to facilitate larger idler pulleys

CHANGELOG.md

@@ -3,6 +3,50 @@
 This changelog is generated by `changelog.py` using manually added semantic version tags to classify commits as breaking changes, additions or fixes.
 
 
+### [v17.10.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.10.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.9.0...v17.10.0 "diff with v17.9.0")
+*   2021-12-12 [`c31f58a`](https://github.com/nophead/NopSCADlib/commit/c31f58a4fdf5163dc56b98e89f1a98d08cdfded2 "show commit") [C.P.](# "Chris Palmer") Updated images and readme.
+
+*   2021-11-27 [`a280e1f`](https://github.com/nophead/NopSCADlib/commit/a280e1fcbd6fe068a186e5c9f609cff62b2974a4 "show commit") [M.B.](# "Martin Budden") Added GT2x9 belt.
+
+### [v17.9.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.9.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.8.0...v17.9.0 "diff with v17.8.0")
+*   2021-12-11 [`a2dfaef`](https://github.com/nophead/NopSCADlib/commit/a2dfaef2b51ffec3f048f0af569b39e8a7dbbeaf "show commit") [C.P.](# "Chris Palmer") Updated readme.
+
+*   2021-11-16 [`9790bdd`](https://github.com/nophead/NopSCADlib/commit/9790bdda11573904bf87c655d1ab7b81736a45e0 "show commit") [M.B.](# "Martin Budden") Added function returning number of links in drag chain.
+
+### [v17.8.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.8.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.7.2...v17.8.0 "diff with v17.7.2")
+*   2021-12-11 [`c4895f8`](https://github.com/nophead/NopSCADlib/commit/c4895f84c7cff48baa14040c2759da15d2a165be "show commit") [C.P.](# "Chris Palmer") Updated image and readme.
+
+*   2021-11-20 [`b1ad206`](https://github.com/nophead/NopSCADlib/commit/b1ad206ce4d29b61f3a9be15adde7f1a51c225b5 "show commit") [M.B.](# "Martin Budden") Rotated conical horihole.
+
+*   2021-11-20 [`da55f86`](https://github.com/nophead/NopSCADlib/commit/da55f86536746657a1e105858109f177d24c362e "show commit") [M.B.](# "Martin Budden") Added variant of drag chain without supports.
+Unsupported drag chain has conical pin and corresponding horihole and is printed with cutout facing upwards.
+
+ * Also made clearance a property of the drag chain so it can be altered for printing chain assemblies
+
+*   2021-12-11 [`43c78fd`](https://github.com/nophead/NopSCADlib/commit/43c78fd1a38de87a210a64c3587bc994731b41c6 "show commit") [C.P.](# "Chris Palmer") Annual image changes due to change of computer.
+
+#### [v17.7.2](https://github.com/nophead/NopSCADlib/releases/tag/v17.7.2 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v17.7.1...v17.7.2 "diff with v17.7.1")
+*   2021-11-13 [`74e5698`](https://github.com/nophead/NopSCADlib/commit/74e569896bd9b4f98bcd7c84322cd358fee8941f "show commit") [C.P.](# "Chris Palmer") Updated images.
+
+*   2021-11-01 [`ed6f8cf`](https://github.com/nophead/NopSCADlib/commit/ed6f8cf5c0877f7e8ad9323cc4fd3a6983a11080 "show commit") [M.B.](# "Martin Budden") Added shading to base of screw sockets to increase visibility.
+
+#### [v17.7.1](https://github.com/nophead/NopSCADlib/releases/tag/v17.7.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v17.7.0...v17.7.1 "diff with v17.7.0")
+*   2021-10-29 [`9464ad5`](https://github.com/nophead/NopSCADlib/commit/9464ad5dbf1c6befaa0059e7cc3f0988d5639173 "show commit") [C.P.](# "Chris Palmer") Fixed knob for pots with split shaft.
+Changed the order of `knob_for_pot()` parameters.
+
+### [v17.7.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.7.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.6.0...v17.7.0 "diff with v17.6.0")
+*   2021-10-28 [`b424bea`](https://github.com/nophead/NopSCADlib/commit/b424bea622d5247fd1e2f1ddd51782aba55277e1 "show commit") [C.P.](# "Chris Palmer") Added printed knobs for pots.
+
+*   2021-10-28 [`c8d9bb7`](https://github.com/nophead/NopSCADlib/commit/c8d9bb7d094408f70cb91354895856cb915cfe00 "show commit") [C.P.](# "Chris Palmer") Potentiometers now create a BOM entry and have a value specified.
+
+### [v17.6.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.6.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.5.0...v17.6.0 "diff with v17.5.0")
+*   2021-10-26 [`f5528c5`](https://github.com/nophead/NopSCADlib/commit/f5528c5a9a51abdd12443a677236ac8610206c20 "show commit") [C.P.](# "Chris Palmer") Single `7_segment` objects can now have multiple digits.
+This is deduced from the digit size compared to the overall size.
+The decimal point is now suppressed if there are not enough pins.
+Added 02531A and 02352A 3 digit displays.
+
+*   2021-10-26 [`09bce09`](https://github.com/nophead/NopSCADlib/commit/09bce09a85fee3f3ac684743467329c18f4ebb73 "show commit") [C.P.](# "Chris Palmer") Typo
+
 ### [v17.5.0](https://github.com/nophead/NopSCADlib/releases/tag/v17.5.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v17.4.0...v17.5.0 "diff with v17.4.0")
 *   2021-10-24 [`bad33da`](https://github.com/nophead/NopSCADlib/commit/bad33da95eb3b20ccbb6e4906dccfe51e8f4372c "show commit") [C.P.](# "Chris Palmer") Updated images and readme.
 

libtest.scad

@@ -123,6 +123,7 @@ use <tests/fixing_block.scad>
 use <tests/flat_hinge.scad>
 use <tests/foot.scad>
 use <tests/handle.scad>
+use <tests/knob.scad>
 use <tests/PCB_mount.scad>
 use <tests/pocket_handle.scad>
 use <tests/printed_box.scad>
@@ -173,16 +174,19 @@ translate([x5, cable_grommets_y + 470]) {
         flat_hinges();
 }
 
-translate([x5, cable_grommets_y + 370])
+translate([x5, cable_grommets_y + 380])
     no_explode() socket_boxes();
 
-translate([x5 + 60, cable_grommets_y + 200])
-    strap_handles();
-
 translate([640, cable_grommets_y + 200])
     printed_pulley_test();
 
-translate([x5, cable_grommets_y + 250])
+translate([x5, cable_grommets_y + 200])
+    knobs();
+
+translate([x5 + 60, cable_grommets_y + 250])
+    strap_handles();
+
+translate([x5, cable_grommets_y + 300])
     handle();
 
 translate([950, 600])

printed/drag_chain.scad

@@ -35,18 +35,17 @@ include <../core.scad>
 use <../utils/horiholes.scad>
 use <../utils/maths.scad>
 
-clearance = 0.1;
-
 function drag_chain_name(type)        = type[0]; //! The name to allow more than one in a project
 function drag_chain_size(type)        = type[1]; //! The internal size and link length
 function drag_chain_travel(type)      = type[2]; //! X travel
 function drag_chain_wall(type)        = type[3]; //! Side wall thickness
 function drag_chain_bwall(type)       = type[4]; //! Bottom wall
 function drag_chain_twall(type)       = type[5]; //! Top wall
-function drag_chain_screw(type)       = type[6]; //! Mounting screw for the ends
-function drag_chain_screw_lists(type) = type[7]; //! Two lists of four bools to say which screws positions are used
+function drag_chain_clearance(type)   = type[6]; //! Clearance around joints
+function drag_chain_supports(type)    = type[7]; //! Whether to print version of chain with or without supports
+function drag_chain_screw(type)       = type[8]; //! Mounting screw for the ends
+function drag_chain_screw_lists(type) = type[9]; //! Two lists of four bools to say which screws positions are used
 
-function drag_chain_clearance() = clearance; //! Clearance around joints.
 
 function drag_chain_radius(type) = //! The bend radius at the pivot centres
     let(s = drag_chain_size(type))
@@ -56,12 +55,15 @@ function drag_chain_z(type) = //! Outside dimension of a 180 bend
     let(os = drag_chain_outer_size(type), s = drag_chain_size(type))
         2 * drag_chain_radius(type) + os.z;
 
-function drag_chain(name, size, travel, wall = 1.6, bwall = 1.5, twall = 1.5, screw = M2_cap_screw, screw_lists = [[1,0,0,1],[1,0,0,1]]) = //! Constructor
-    [name, size, travel, wall, bwall, twall, screw, screw_lists];
+function drag_chain(name, size, travel, wall = 1.6, bwall = 1.5, twall = 1.5, clearance = 0.1, supports = true, screw = M2_cap_screw, screw_lists = [[1,0,0,1],[1,0,0,1]]) = //! Constructor
+    [name, size, travel, wall, bwall, twall, clearance, supports, screw, screw_lists];
 
 function drag_chain_outer_size(type) = //! Link outer dimensions
     let(s = drag_chain_size(type), z = s.z + drag_chain_bwall(type) + drag_chain_twall(type))
-        [s.x + z, s.y + 4 * drag_chain_wall(type) + 2 * clearance, z];
+        [s.x + z, s.y + 4 * drag_chain_wall(type) + 2 * drag_chain_clearance(type), z];
+
+function drag_chain_links(type) = //! Number of links in chain
+    ceil(drag_chain_travel(type) / drag_chain_size(type).x) + 4;
 
 function screw_lug_radius(screw) = //! Radius of a screw lug
     corrected_radius(screw_clearance_radius(screw)) + 3.1 * extrusion_width;
@@ -85,6 +87,7 @@ module drag_chain_screw_positions(type, end) { //! Place children at the screw p
     r = screw_lug_radius(drag_chain_screw(type));
     s = drag_chain_size(type);
     os = drag_chain_outer_size(type);
+    clearance = drag_chain_clearance(type);
     R = os.z / 2;
     x0 = end ? R + norm([drag_chain_cam_x(type), R - drag_chain_twall(type)]) + clearance + r : r;
     x1 = end ? os.x - r : os.x - 2 * R - clearance - r;
@@ -99,7 +102,7 @@ function drag_chain_cam_x(type) = // how far the cam sticks out
     let(s = drag_chain_size(type),
         r =  drag_chain_outer_size(type).z / 2,
         wall =  drag_chain_wall(type),
-        cam_r = s.x - 2 * clearance - wall - r,  // inner_x_normal - clearance - r
+        cam_r = s.x - 2 * drag_chain_clearance(type) - wall - r,  // inner_x_normal - clearance - r
         twall = drag_chain_twall(type)
     )   min(sqrt(max(sqr(cam_r) - sqr(r - twall), 0)), r);
 
@@ -111,8 +114,15 @@ module drag_chain_link(type, start = false, end = false, check_kids = true) { //
     bwall = drag_chain_bwall(type);
     twall = drag_chain_twall(type);
     os = drag_chain_outer_size(type);
+    clearance = drag_chain_clearance(type);
+    supports = drag_chain_supports(type);
     r = os.z / 2;
-    pin_r = r / 2;
+    // initial estimates of pin_r and pin_h
+    pin_r0 = r / 2 - 0.2;
+    pin_h0 = min(wall + clearance, 2 * pin_r0 - 1);
+     // for conical pin: ensure minimum radius of top of pin and pin does not overlap cutout
+    pin_r = supports ? r / 2 : min(r / 2 - 0.2, (os.z - 2 * twall - 3 * pin_h0 / 4 - 0.2) / 2);
+    pin_h = min(wall + clearance, 2 * pin_r - 1);
 
     socket_x = r;
     pin_x = socket_x + s.x;
@@ -123,44 +133,51 @@ module drag_chain_link(type, start = false, end = false, check_kids = true) { //
     inner_x = start ? 0 : outer_normal_x - wall; // s.x - clearance - wall
 
     roof_x_normal = 2 * r - twall;
-    roof_x = start ? 0 : roof_x_normal;
-
-    floor_x = start ? 0 : 2 * r;
     cam_x = drag_chain_cam_x(type);
     assert(r + norm([drag_chain_cam_x(type), r - drag_chain_twall(type)]) + clearance <= inner_x || start, "Link must be longer");
 
+    vflip(!supports)
     difference() {
         union() {
             for(side = [-1, 1])
                 rotate([90, 0, 0]) {
                     // Outer cheeks
                     translate_z(side * (os.y / 2 - wall / 2))
-                        linear_extrude(wall, center = true)
-                            difference() {
+                        difference() {
+                            linear_extrude(wall, center = true)
                                 hull() {
                                     if(start)
                                         square([eps, os.z]);
                                     else
                                         translate([socket_x, r])
-                                            rotate(180)
+                                            rotate(supports ? 180 : 0)
                                                 teardrop(r = r, h = 0);
 
                                     translate([outer_end_x - eps, 0])
                                         square([eps, os.z]);
                                 }
                                 if(!start)
-                                    translate([socket_x, r])
-                                        horihole(pin_r, r);
+                                    if(supports)
+                                        translate([socket_x, r, 0])
+                                            horihole(pin_r, r, wall + 2*eps);
+                                    else
+                                        translate([socket_x, r, -side * (wall / 2 + clearance)])
+                                            rotate(180)
+                                                hull() {
+                                                    horihole(r = pin_r + pin_h / 2, z = r, h = eps);
+                                                    translate_z(side * pin_h)
+                                                        horihole(r = pin_r - pin_h / 2, z = r, h = eps);
+                                                }
                             }
                     // Inner cheeks
-                    translate_z(side * (s.y / 2 + wall / 2))
+                    translate_z(side * (s.y / 2 + wall / 2)) {
                         linear_extrude(wall, center = true)
                             difference() {
                                 union() {
                                     hull() {
                                         if(!end) {
                                             translate([pin_x, r])
-                                                rotate(180)
+                                                rotate(supports ? 180 : 0)
                                                     teardrop(r = r, h = 0);
 
                                             translate([pin_x, twall])
@@ -186,31 +203,39 @@ module drag_chain_link(type, start = false, end = false, check_kids = true) { //
                                                     square(os.z);
                                     }
                             }
-                    // Pin
-                    if(!end)
-                        translate([pin_x, r, side * (s.y / 2 + wall + clearance)])
-                            horicylinder(r = pin_r, z = r, h = 2 * wall);
+                        // Pin
+                        if(!end)
+                            if(supports)
+                                translate([pin_x, r, side * (wall / 2 + clearance)])
+                                    horicylinder(r = pin_r, z = r, h = 2 * wall + eps);
+                            else
+                                translate([pin_x, r, side * wall / 2])
+                                    vflip(side == -1)
+                                        cylinder(r1 = pin_r + pin_h / 2, r2 = pin_r - pin_h / 2, h = pin_h + eps);
+                    }
 
                     // Cheek joint
                     translate([inner_x, 0, side * (s.y / 2 + wall) - 0.5])
                         cube([outer_end_x - inner_x, os.z, 1]);
                 }
 
-            // Roof, actually the floor when printed
+            // Roof, actually the floor when printed with supports
+            roof_x = start ? 0 : roof_x_normal;
             roof_end = end ? s.x + 2 * r : s.x + r - twall - clearance;
-            translate([roof_x, -s.y / 2 - 0.5])
-                cube([roof_end - roof_x , s.y + 1, twall]);
+            translate([roof_x, -s.y / 2 - wall, 0]) {
+                cube([roof_end - roof_x, s.y + 2 * wall, twall]);
+                translate([0, -wall, 0])
+                    cube([s.x - roof_x - clearance, s.y + 4 * wall, twall]);
+            }
 
-            translate([roof_x, -os.y / 2 + 0.5])
-                cube([s.x - clearance - roof_x, os.y - 1, twall]);
-
-            // Floor, actually the roof when printed
+            // Floor, actually the roof when printed with supports
+            floor_x = start ? 0 : 2 * r;
             floor_end = end ? s.x + 2 * r : s.x + r;
-            translate([floor_x, -s.y / 2 - wall, os.z - bwall])
+            translate([floor_x, -s.y / 2 - wall, os.z - bwall]) {
                 cube([floor_end - floor_x, s.y + 2 * wall, bwall]);
-
-            translate([floor_x, -os.y / 2 + 0.5,  os.z - bwall])
-                cube([s.x - floor_x - clearance, os.y -1, bwall]);
+                translate([0, -wall, 0])
+                    cube([s.x - floor_x - clearance, s.y + 4 * wall, bwall]);
+            }
 
             if(start || end) {
                 drag_chain_screw_positions(type, end)
@@ -223,16 +248,16 @@ module drag_chain_link(type, start = false, end = false, check_kids = true) { //
                 }
                 children();
             }
-        }
+        } // end union
+
         if(start || end)
             translate_z(-eps)
                 drag_chain_screw_positions(type, end)
                     rotate($a)
                         poly_cylinder(r = screw_clearance_radius(drag_chain_screw(type)), h = os.z + 2 * eps, center = false);
+    } // end difference
 
-    }
-
-    if(show_supports() && !end) {
+    if(supports && show_supports() && !end) {
         for(side = [-1, 1]) {
             w = 2.1 * extrusion_width;
             translate([s.x + r + cam_x - w / 2, side * (s.y / 2 + wall / 2), twall / 2])
@@ -255,16 +280,15 @@ module _drag_chain_assembly(type, pos = 0, render = false) {
     s = drag_chain_size(type);
     x = (1 + exploded()) * s.x;
     r = drag_chain_radius(type) * x / s.x;
-    travel = drag_chain_travel(type);
-    links = ceil(travel / s.x);
-    actual_travel = links * s.x;
+    links = drag_chain_links(type);
+    actual_travel = (links - 4) * s.x;
     z = drag_chain_outer_size(type).z;
 
     zb = z / 2;                                     // z of bottom track
     c = [actual_travel / 2 + pos / 2, 0, r + zb];   // centre of bend
 
     points = [                                      // Calculate list of hinge points
-        for(i = 0, p = [0, 0, z / 2 + 2 * r]; i < links + 5;
+        for(i = 0, p = [0, 0, z / 2 + 2 * r]; i < links + 1;
             i = i + 1,
             dx = p.z > c.z ? x : -x,
             p = max(p.x + dx, p.x) <= c.x ? p + [dx, 0, 0]      // Straight sections
@@ -277,11 +301,12 @@ module _drag_chain_assembly(type, pos = 0, render = false) {
 
     module link(n)                                  // Position and colour link with origin at the hinge hole
         translate([-z / 2, 0, -z / 2]) {
-            stl_colour(n < 0 || n == npoints - 1 ? pp3_colour : n % 2 ? pp1_colour : pp2_colour)
-                render_if(render)
-                    drag_chain_link(type, start = n == -1, end = n == npoints - 1, check_kids = false)
-                        let($fasteners = 0)
-                            children();
+            vflip(!drag_chain_supports(type))
+                stl_colour(n < 0 || n == npoints - 1 ? pp3_colour : n % 2 ? pp1_colour : pp2_colour)
+                    render_if(render)
+                        drag_chain_link(type, start = n == -1, end = n == npoints - 1, check_kids = false)
+                            let($fasteners = 0)
+                                children();
 
             let($fasteners = 1) children();
         }

printed/knob.scad

@@ -0,0 +1,171 @@
+//
+// NopSCADlib Copyright Chris Palmer 221
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Parametric knobs for potentiometers and encoders.
+//!
+//! A knob can be constructed by specififying all the parameters or the potentiometer can be specified to customise it for its shaft with a recess to clear the nut, washer and thread.
+//! An optional skirt and / or a pointer can be specified.
+//!
+//! The STL includes a support membrane that needs to be cut out and a thread needs to be tapped for the grub screw.
+//
+
+include <../core.scad>
+use <../utils/hanging_hole.scad>
+use <../utils/rounded_polygon.scad>
+use <../vitamins/potentiometer.scad>
+
+clearance = 0.2;
+
+function knob_name(type)     = type[0]; //! Name for the stl maker
+function knob_top_d(type)    = type[1]; //! Diameter at the top
+function knob_bot_d(type)    = type[2]; //! Diameter at the bottom
+function knob_height(type)   = type[3]; //! Height
+function knob_corner_r(type) = type[4]; //! Rounded top corner
+function knob_shaft_d(type)  = type[5]; //! Shaft diameter
+function knob_shaft_len(type)= type[6]; //! Shaft length
+function knob_flat_d(type)   = type[7]; //! The shaft diameter at the flat
+function knob_flat_h(type)   = type[8]; //! The length of the flat
+function knob_screw(type)    = type[9]; //! The grub screw type
+function knob_skirt(type)    = type[10]; //! Skirt diameter and thickness
+function knob_recess(type)   = type[11]; //! Recess diameter and thickness to clear nut and thread, diameter, nut height, thread height
+function knob_pointer(type)  = type[12]; //! Pointer outside radius, [point width, back width] and height height
+
+function knob(name = "knob", top_d = 12, bot_d = 15, height = 18, shaft_length, skirt = [20, 2], pointer = false, corner_r = 2, screw = M3_grub_screw, shaft_d, flat_d, flat_h, recess) = //! Constructor
+[
+    name, top_d, bot_d, height, corner_r, shaft_d, shaft_length, flat_d, flat_h, screw, skirt, recess, pointer
+];
+
+function knob_for_pot(pot, thickness, z = 1, washer = true, top_d = 12, bot_d = 15, height = 0, shaft_length = undef, skirt = [20, 2], pointer = false, corner_r = 2, screw = M3_grub_screw) =  //! Construct a knob to fit specified pot
+    let(s = pot_shaft(pot),
+        washer = washer && pot_washer(pot) ? pot_washer(pot) : [0, 0],
+        nut = pot_nut(pot) ? pot_nut(pot) : [pot_thread_d(pot) * cos(30), pot_thread_h(pot) - thickness],
+        shaft_length = is_undef(shaft_length) ? s.z : min(shaft_length, s.z),
+        h = round_to_layer(shaft_length + pot_thread_h(pot) - thickness - z),
+        height = max(height, h + 1),
+        recess = [(z > washer.y ? nut.x / cos(30) : washer.x) + 0.4, round_to_layer(nut.y + washer.y - z + layer_height), round_to_layer(pot_thread_h(pot) - z - thickness + 2 * layer_height)],
+        flat_d = s.y + 0.06,
+        flat_h = min(s[3], shaft_length)
+    )
+    knob(name = str(pot[0], "_knob"),
+         top_d = top_d,
+         bot_d = bot_d,
+         height = height,
+         corner_r = corner_r,
+         screw = screw,
+         skirt = skirt,
+         pointer = pointer,
+         shaft_d = s.x,
+         shaft_length = h,
+         flat_d = flat_d,
+         flat_h = flat_h,
+         recess = recess);
+
+function knob_screw_z(type) = knob_shaft_len(type) - knob_flat_h(type) / 2;
+
+module knob(type, supports = true) { //! Generate the STL for a knob
+    r_top = knob_top_d(type) / 2;
+    r_bot = knob_bot_d(type) / 2;
+    h = knob_height(type);
+    r = knob_corner_r(type);
+    screw = knob_screw(type);
+    sr = knob_shaft_d(type) / 2 + (screw ? clearance : 0);
+    top_wall = h - knob_shaft_len(type);
+    fr = knob_flat_d(type) - sr + 2 * clearance;
+    fh = knob_flat_h(type);
+    skirt = knob_skirt(type);
+    recess = knob_recess(type);
+    pointer = knob_pointer(type);
+
+    stl(knob_name(type))
+    {
+        difference() {
+            union() {
+                rotate_extrude() {
+                    rounded_polygon([
+                        [0, h, 0],
+                        [r_top - r, h - r, r],
+                        [r_bot, 0, 0],
+                        [0, 0, 0],
+                    ]);
+
+                    if(skirt)
+                        square([skirt.x / 2, skirt.y]);
+                }
+                if(pointer)
+                    linear_extrude(pointer.z)
+                        rotate(-90)
+                            hull() {
+                                translate([pointer.x, 0])
+                                    square([eps, pointer.y[0]], center = true);
+
+                                translate([r_bot, 0])
+                                    square([eps, pointer.y[1]], center = true);
+                            }
+            }
+            shaft_z = recess ? recess.z + (supports ? layer_height : -eps) : -eps;
+            translate_z(shaft_z) {
+                h = h - top_wall - shaft_z;
+                linear_extrude(h)
+                    difference() {
+                        poly_circle(sr);
+
+                        if(fr > 0)
+                            translate([-sr, fr])
+                                square([2 * sr, sr]);
+                    }
+
+                if(h > fh)
+                    poly_cylinder(sr, round_to_layer(h - fh), center = false);
+            }
+
+            if(recess)
+                translate_z(-eps)
+                    hull() {
+                        poly_cylinder(r = recess.x / 2, h = recess.y + eps, center = false);
+
+                        linear_extrude(recess.z + eps)
+                            offset(min(-(recess.z - recess.y), 0))
+                                poly_circle(recess.x / 2);
+                    }
+
+            if(screw)
+                translate_z(knob_screw_z(type))
+                    rotate([90, 0, 180])
+                        teardrop_plus(r = screw_pilot_hole(screw), h = max(r_top, r_bot) + eps, center = false);
+        }
+    }
+}
+
+//! Knob with grub screw in place
+module knob_assembly(type) explode(40, explode_children = true) { //! Assembly with the grub screw in place
+    sr = knob_shaft_d(type) / 2;
+    fr = knob_flat_d(type) < sr ? knob_flat_d(type) - sr : sr;
+    r_top = knob_top_d(type) / 2;
+    r_bot = knob_bot_d(type) / 2;
+    screw_length = screw_shorter_than(min(r_top, r_bot) - fr);
+    screw = knob_screw(type);
+
+    stl_colour(pp1_colour) render() knob(type, supports = false);
+
+    if(screw)
+        translate([0, (fr + screw_length), knob_screw_z(type)])
+            rotate([90, 0, 180])
+                screw(screw, screw_length);
+}

readme.md

@@ -35,18 +35,18 @@ A list of changes classified as breaking, additions or fixes is maintained in [C
 <tr><td> <a href = "#Cable_strips">Cable_strips</a> </td><td> <a href = "#Microswitches">Microswitches</a> </td><td> <a href = "#Sheets">Sheets</a> </td><td> <a href = "#Flat_hinge">Flat_hinge</a> </td><td> <a href = "#Offset">Offset</a> </td><td></td></tr>
 <tr><td> <a href = "#Cameras">Cameras</a> </td><td> <a href = "#Microview">Microview</a> </td><td> <a href = "#Spades">Spades</a> </td><td> <a href = "#Foot">Foot</a> </td><td> <a href = "#Quadrant">Quadrant</a> </td><td></td></tr>
 <tr><td> <a href = "#Circlips">Circlips</a> </td><td> <a href = "#Modules">Modules</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#Handle">Handle</a> </td><td> <a href = "#Round">Round</a> </td><td></td></tr>
-<tr><td> <a href = "#Components">Components</a> </td><td> <a href = "#Nuts">Nuts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#PCB_mount">PCB_mount</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
-<tr><td> <a href = "#DIP">DIP</a> </td><td> <a href = "#O_ring">O_ring</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td> <a href = "#PSU_shroud">PSU_shroud</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
-<tr><td> <a href = "#D_connectors">D_connectors</a> </td><td> <a href = "#Opengrab">Opengrab</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#Pocket_handle">Pocket_handle</a> </td><td> <a href = "#Rounded_triangle">Rounded_triangle</a> </td><td></td></tr>
-<tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#Press_fit">Press_fit</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
-<tr><td> <a href = "#Extrusion_brackets">Extrusion_brackets</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
-<tr><td> <a href = "#Extrusions">Extrusions</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#Printed_pulleys">Printed_pulleys</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
-<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#Panel_meters">Panel_meters</a> </td><td> <a href = "#Variacs">Variacs</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
-<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#Pillars">Pillars</a> </td><td> <a href = "#Veroboard">Veroboard</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#Pillow_blocks">Pillow_blocks</a> </td><td> <a href = "#Washers">Washers</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Pin_headers">Pin_headers</a> </td><td> <a href = "#Wire">Wire</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Potentiometers">Potentiometers</a> </td><td> <a href = "#Zipties">Zipties</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Pulleys">Pulleys</a> </td><td></td><td></td><td></td><td></td></tr>
+<tr><td> <a href = "#Components">Components</a> </td><td> <a href = "#Nuts">Nuts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#Knob">Knob</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
+<tr><td> <a href = "#DIP">DIP</a> </td><td> <a href = "#O_ring">O_ring</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td> <a href = "#PCB_mount">PCB_mount</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
+<tr><td> <a href = "#D_connectors">D_connectors</a> </td><td> <a href = "#Opengrab">Opengrab</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#PSU_shroud">PSU_shroud</a> </td><td> <a href = "#Rounded_triangle">Rounded_triangle</a> </td><td></td></tr>
+<tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#Pocket_handle">Pocket_handle</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
+<tr><td> <a href = "#Extrusion_brackets">Extrusion_brackets</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#Press_fit">Press_fit</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
+<tr><td> <a href = "#Extrusions">Extrusions</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
+<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#Panel_meters">Panel_meters</a> </td><td> <a href = "#Variacs">Variacs</a> </td><td> <a href = "#Printed_pulleys">Printed_pulleys</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
+<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#Pillars">Pillars</a> </td><td> <a href = "#Veroboard">Veroboard</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#Pillow_blocks">Pillow_blocks</a> </td><td> <a href = "#Washers">Washers</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Pin_headers">Pin_headers</a> </td><td> <a href = "#Wire">Wire</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Potentiometers">Potentiometers</a> </td><td> <a href = "#Zipties">Zipties</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Pulleys">Pulleys</a> </td><td></td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
 </table>
 
 ---
@@ -356,6 +356,7 @@ Individual teeth are not drawn, instead they are represented by a lighter colour
 |   1 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 128mm |
 |   1 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 552mm |
 |   2 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 556mm |
+|   1 | `belt(GT2x9, [ ... ])` |  Belt GT2 x 9mm x 128mm |
 |   1 | `belt(T2p5x6, [ ... ])` |  Belt T2.5 x 6mm x 130mm |
 |   1 | `belt(T5x10, [ ... ])` |  Belt T5 x 10mm x 130mm |
 |   1 | `belt(T5x6, [ ... ])` |  Belt T5 x 6mm x 130mm |
@@ -2390,6 +2391,7 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 ### Vitamins
 | Qty | Module call | BOM entry |
 | ---:|:--- |:---|
+|   1 | `potentiometer(BTT_encoder)` |  BTT_encoder |
 |   1 | `box_header(2p54header, 4, 2)` |  Box header 4 x 2 |
 |   1 | `d_plug(DCONN9, pcb = true)` |  D-type 9 way PCB mount plug |
 |   1 | `dil_socket(12, 15.24)` |  DIL socket 24 x 0.6" |
@@ -2397,6 +2399,7 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   1 | `pdip(24, 27C32, w = 15.24)` |  IC 27C32 PDIP24 |
 |   1 | `pdip(8, NE555)` |  IC NE555 PDIP8 |
 |   1 | `idc_transition(2p54header, 5)` |  IDC transition header 5 x 2 |
+|   1 | `potentiometer(KY_040_encoder)` |  KY_040_encoder |
 |   1 | `led(LED10mm, "yellow")` |  LED 10 mm yellow |
 |   1 | `led(LED3mm)` |  LED 3 mm red |
 |   1 | `led(LED5mm, "orange")` |  LED 5 mm orange |
@@ -2826,10 +2829,19 @@ Potentiometers and rotary encoders
 | Module | Description |
 |:--- |:--- |
 | `pot_nut(type, washer = true)` | Draw the nut for a potentiometer and possibly a washer |
-| `potentiometer(type, thickness = 3, shaft_length = undef)` | Draw a potentiometer with nut spaced by specified thickness |
+| `potentiometer(type, thickness = 3, shaft_length = undef, value = false)` | Draw a potentiometer with nut spaced by specified thickness |
 
 ![potentiometers](tests/png/potentiometers.png)
 
+### Vitamins
+| Qty | Module call | BOM entry |
+| ---:|:--- |:---|
+|   1 | `potentiometer(BTT_encoder)` |  BTT_encoder |
+|   1 | `potentiometer(KY_040_encoder)` |  KY_040_encoder |
+|   1 | `potentiometer(imperial_pot)` |  Potentiometer imperial_pot |
+|   1 | `potentiometer(imperial_pot_x2)` |  Potentiometer imperial_pot_x2 |
+|   1 | `potentiometer(metric_pot)` |  Potentiometer metric_pot |
+
 
 <a href="#top">Top</a>
 
@@ -4929,10 +4941,12 @@ to the assembly, for example to add inserts.
 | Function | Description |
 |:--- |:--- |
 | `drag_chain_bwall(type)` | Bottom wall |
+| `drag_chain_clearance(type)` | Clearance around joints |
 | `drag_chain_name(type)` | The name to allow more than one in a project |
 | `drag_chain_screw(type)` | Mounting screw for the ends |
 | `drag_chain_screw_lists(type)` | Two lists of four bools to say which screws positions are used |
 | `drag_chain_size(type)` | The internal size and link length |
+| `drag_chain_supports(type)` | Whether to print version of chain with or without supports |
 | `drag_chain_travel(type)` | X travel |
 | `drag_chain_twall(type)` | Top wall |
 | `drag_chain_wall(type)` | Side wall thickness |
@@ -4940,8 +4954,8 @@ to the assembly, for example to add inserts.
 ### Functions
 | Function | Description |
 |:--- |:--- |
-| `drag_chain(name, size, travel, wall = 1.6, bwall = 1.5, twall = 1.5, screw = M2_cap_screw, screw_lists = [[1,0,0,1],[1,0,0,1]])` | Constructor |
-| `drag_chain_clearance()` | Clearance around joints. |
+| `drag_chain(name, size, travel, wall = 1.6, bwall = 1.5, twall = 1.5, clearance = 0.1, supports = true, screw = M2_cap_screw, screw_lists = [[1,0,0,1],[1,0,0,1]])` | Constructor |
+| `drag_chain_links(type)` | Number of links in chain |
 | `drag_chain_outer_size(type)` | Link outer dimensions |
 | `drag_chain_radius(type)` | The bend radius at the pivot centres |
 | `drag_chain_z(type)` | Outside dimension of a 180 bend |
@@ -5278,6 +5292,75 @@ Printed handle that can be printed without needing support material due to its t
 |   1 | handle_assembly |
 
 
+<a href="#top">Top</a>
+
+---
+<a name="Knob"></a>
+## Knob
+Parametric knobs for potentiometers and encoders.
+
+A knob can be constructed by specififying all the parameters or the potentiometer can be specified to customise it for its shaft with a recess to clear the nut, washer and thread.
+An optional skirt and / or a pointer can be specified.
+
+The STL includes a support membrane that needs to be cut out and a thread needs to be tapped for the grub screw.
+
+[printed/knob.scad](printed/knob.scad) Implementation.
+
+[tests/knob.scad](tests/knob.scad) Code for this example.
+
+### Properties
+| Function | Description |
+|:--- |:--- |
+| `knob_bot_d(type)` | Diameter at the bottom |
+| `knob_corner_r(type)` | Rounded top corner |
+| `knob_flat_d(type)` | The shaft diameter at the flat |
+| `knob_flat_h(type)` | The length of the flat |
+| `knob_height(type)` | Height |
+| `knob_name(type)` | Name for the stl maker |
+| `knob_pointer(type)` | None |
+| `knob_recess(type)` | Recess diameter and thickness to clear nut and thread, diameter, nut height, thread height |
+| `knob_screw(type)` | The grub screw type |
+| `knob_shaft_d(type)` | Shaft diameter |
+| `knob_shaft_len(type)` | Shaft length |
+| `knob_skirt(type)` | Skirt diameter and thickness |
+| `knob_top_d(type)` | Diameter at the top |
+
+### Functions
+| Function | Description |
+|:--- |:--- |
+| `knob(name = "knob", top_d = 12, bot_d = 15, height = 18, shaft_length, skirt = [20, 2], pointer = false, corner_r = 2, screw = M3_grub_screw, shaft_d, flat_d, flat_h, recess)` | Constructor |
+| `knob_for_pot(pot, thickness, z = 1, washer = true, top_d = 12, bot_d = 15, height = 0, shaft_length = undef, skirt = [20, 2], pointer = false, corner_r = 2, screw = M3_grub_screw)` | Construct a knob to fit specified pot |
+
+### Modules
+| Module | Description |
+|:--- |:--- |
+| `knob(type, supports = true)` | Generate the STL for a knob |
+| `knob_assembly(type) explode(40, explode_children = true)` | Assembly with the grub screw in place |
+
+![knob](tests/png/knob.png)
+
+### Vitamins
+| Qty | Module call | BOM entry |
+| ---:|:--- |:---|
+|   1 | `potentiometer(BTT_encoder)` |  BTT_encoder |
+|   1 | `potentiometer(KY_040_encoder)` |  KY_040_encoder |
+|   1 | `potentiometer(imperial_pot)` |  Potentiometer imperial_pot |
+|   1 | `potentiometer(imperial_pot_x2)` |  Potentiometer imperial_pot_x2 |
+|   1 | `potentiometer(metric_pot)` |  Potentiometer metric_pot |
+|   1 | `screw(M3_grub_screw, 3)` |  Screw M3 grub x  3mm |
+|   2 | `screw(M3_grub_screw, 4)` |  Screw M3 grub x  4mm |
+|   1 | `screw(M3_grub_screw, 6)` |  Screw M3 grub x  6mm |
+
+### Printed
+| Qty | Filename |
+| ---:|:--- |
+|   1 | BTT_encoder_knob.stl |
+|   1 | KY_040_encoder_knob.stl |
+|   1 | imperial_pot_knob.stl |
+|   1 | imperial_pot_x2_knob.stl |
+|   1 | metric_pot_knob.stl |
+
+
 <a href="#top">Top</a>
 
 ---
@@ -5985,9 +6068,9 @@ allows flexible positioning of the motors.
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| `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 |
-| `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 |
-| `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 |
+| `coreXY(type, size, pos, separation, x_gap = 0, plain_idler_offset = [0, 0], upper_drive_pulley_offset = [0, 0], lower_drive_pulley_offset = [0, 0], show_pulleys = false, left_lower = false)` | Wrapper module to draw both belts of a coreXY setup |
+| `coreXY_belts(type, carriagePosition, coreXYPosBL, coreXYPosTR, separation, x_gap = 0, plain_idler_offset = [0, 0], upper_drive_pulley_offset = [0, 0], lower_drive_pulley_offset = [0, 0], show_pulleys = false, left_lower = false)` | Draw the coreXY belts |
+| `coreXY_half(type, size, pos, separation_y = 0, x_gap = 0, plain_idler_offset = [0, 0], drive_pulley_offset = [0, 0], show_pulleys = false, lower_belt = false, hflip = false)` | Draw one belt of a coreXY setup |
 
 ![core_xy](tests/png/core_xy.png)
 
@@ -5995,7 +6078,7 @@ allows flexible positioning of the motors.
 | Qty | Module call | BOM entry |
 | ---:|:--- |:---|
 |   1 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 728mm |
-|   1 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 824mm |
+|   1 | `belt(GT2x6, [ ... ])` |  Belt GT2 x 6mm x 790mm |
 |   7 | `pulley(GT2x16_toothed_idler)` |  Pulley GT2 idler 16 teeth |
 |   3 | `pulley(GT2x16_plain_idler)` |  Pulley GT2 idler smooth 9.63mm |
 |   2 | `pulley(GT2x20ob_pulley)` |  Pulley GT2OB 20 teeth |

scripts/changelog.py

@@ -82,6 +82,7 @@ def codify(word, url):
 
 
 def fixup_comment(comment, url):
+    comment = comment.replace('cnc_bit+_r', 'cnc_bit_r')
     """ markup code words and fix new paragraphs """
     result = ''
     word = ''
@@ -161,6 +162,6 @@ if __name__ == '__main__':
 
             # 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):
+            if not c.comment.startswith('Merge branch') and not c.comment.startswith('Merge pull') and not re.match(r'U..ated chang.*log.*', 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)
     do_cmd(('codespell -w -L od ' + filename).split())

tests/core_xy.scad

@@ -30,22 +30,25 @@ module coreXY_belts_test() {
     plain_idler = coreXY_plain_idler(coreXY_type);
     toothed_idler = coreXY_toothed_idler(coreXY_type);
 
+    pos = [100, 50];
     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];
+    x_gap = 10;
 
-    upper_drive_pulley_offset = [40, 10];
+    plain_idler_offset = [10, 5];
+    upper_drive_pulley_offset = [40, 0];
     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,
+        pos,
+        coreXYPosBL,
+        coreXYPosTR,
+        separation,
+        x_gap,
+        plain_idler_offset,
+        upper_drive_pulley_offset,
+        lower_drive_pulley_offset,
         show_pulleys = true);
 
 
@@ -56,18 +59,18 @@ module coreXY_belts_test() {
 
         // 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))
+            translate(coreXY_drive_plain_idler_offset(coreXY_type) + plain_idler_offset)
+                translate([0, -upper_drive_pulley_offset.y, -pulley_offset(plain_idler)])
                     screw(M3_cap_screw, 20);
             translate(coreXY_drive_toothed_idler_offset(coreXY_type))
-                translate_z(-pulley_offset(toothed_idler))
+                translate([0, -upper_drive_pulley_offset.y, -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))
+            translate([-pulley_od(plain_idler), coreXY_drive_plain_idler_offset(coreXY_type).y + plain_idler_offset.y])
+                translate([0, -upper_drive_pulley_offset.y, -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))
+            translate([2*coreXY_drive_pulley_x_alignment(coreXY_type) + plain_idler_offset.x, coreXY_drive_toothed_idler_offset(coreXY_type).y])
+                translate([0, -upper_drive_pulley_offset.y, -pulley_offset(toothed_idler)])
                     screw(M3_cap_screw, 20);
         }
     }
@@ -79,18 +82,18 @@ module coreXY_belts_test() {
 
         // 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))
+            translate([-coreXY_drive_plain_idler_offset(coreXY_type).x - plain_idler_offset.x, coreXY_drive_plain_idler_offset(coreXY_type).y + plain_idler_offset.y])
+                translate([0, -lower_drive_pulley_offset.y, -pulley_offset(plain_idler)])
                     screw(M3_cap_screw, 20);
             translate(coreXY_drive_toothed_idler_offset(coreXY_type))
-                translate_z(-pulley_offset(toothed_idler))
+                translate([0, -lower_drive_pulley_offset.y, -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))
+            translate([pulley_od(plain_idler), coreXY_drive_plain_idler_offset(coreXY_type).y + plain_idler_offset.y])
+                translate([0, -lower_drive_pulley_offset.y, -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))
+            translate([-2*coreXY_drive_pulley_x_alignment(coreXY_type) - plain_idler_offset.x, coreXY_drive_toothed_idler_offset(coreXY_type).y])
+                translate([0, -lower_drive_pulley_offset.y, -pulley_offset(toothed_idler)])
                     screw(M3_cap_screw, 20);
         }
     }
@@ -118,13 +121,13 @@ module coreXY_belts_test() {
         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])
+        translate([coreXYPosBL.x + separation.x + coreXY_plain_idler_offset(coreXY_type).x + (upper_drive_pulley_offset.x == 0 ? 0 : plain_idler_offset.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])
+        translate([coreXYPosTR.x - coreXY_plain_idler_offset(coreXY_type).x - (lower_drive_pulley_offset.x == 0 ? 0 : plain_idler_offset.x), separation.y + coreXY_plain_idler_offset(coreXY_type).y, 0])
             screw(M3_cap_screw, 20);
     }
 }

tests/knob.scad

@@ -0,0 +1,58 @@
+//
+// 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/>.
+//
+z = 1; // [0: 5]
+thickness = 3; // [0: 5]
+shaft_length = 10;
+
+include <../core.scad>
+use <../printed/knob.scad>
+use <../utils/layout.scad>
+
+include <../vitamins/potentiometers.scad>
+
+knobs = [for(i = [0 : len(potentiometers) - 1]) let(p = potentiometers[i])
+     knob_for_pot(p, thickness, z, shaft_length = pot_shaft(p).z > 20 ? shaft_length : undef,
+                  top_d   = [10,    12,      20,    16,        16       ][i],
+                  bot_d   = [10,    15,      20,    20,        20       ][i],
+                  skirt   = [false, [20, 2], false,      [27, 1.5], [27, 1.5]][i],
+                  pointer = [false, false,   [14, [1, 5], 2], [13.5, [1, 1], 3], [13.5, [1, 3], 3]][i],
+                  screw = let(s = pot_shaft(p)) s.y > s.x / 2 ? M3_grub_screw : false
+                 )];
+
+
+module knobs(show_pot = false)
+    layout([for(p = potentiometers) pot_size(p).x], 5) let(p = potentiometers[$i])
+        if($preview) {
+            translate_z(z)
+                knob_assembly(knobs[$i]);
+
+            if(show_pot)
+                translate_z(-thickness)
+                    vflip() {
+                        potentiometer(p, shaft_length = shaft_length);
+
+                        translate_z(-thickness)
+                            pot_nut(p);
+                    }
+        }
+        else
+            knob(knobs[$i]);
+
+
+knobs(true);

utils/core_xy.scad

@@ -30,7 +30,6 @@
 //! allows flexible positioning of the motors.
 //
 include <../utils/core/core.scad>
-include <../vitamins/belts.scad>
 include <../vitamins/pulleys.scad>
 
 
@@ -69,7 +68,7 @@ function coreXY_drive_plain_idler_offset(type) = //! Offset of plain drive idler
     [ 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
+module coreXY_half(type, size, pos, separation_y = 0, x_gap = 0, plain_idler_offset = [0, 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);
@@ -91,20 +90,20 @@ module coreXY_half(type, size, pos, separation_y = 0, x_gap = 0, plain_idler_off
 
     // 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
+    p3t = [ -size.x / 2 + (drive_pulley_offset.x > 0 ? 0 : plain_idler_offset.x + 2 * coreXY_drive_pulley_x_alignment(type)),
+             size.y / 2 + coreXY_drive_pulley_x_alignment(type)
     ];
 
     // 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,
+    p4 = [ -size.x / 2 + pulley_od(p4_type) / 2 + pulley_od(p3d_type) / 2 + coreXY_drive_pulley_x_alignment(type) + (drive_pulley_offset.x == 0 ? 0 : plain_idler_offset.x),
            -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
+            size.y / 2 - pulley_od(p3p_type) / 2 - pulley_od(p3d_type) / 2 + plain_idler_offset.y
     ];
 
     // Start and end points
@@ -180,7 +179,7 @@ module coreXY_half(type, size, pos, separation_y = 0, x_gap = 0, plain_idler_off
         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
+module coreXY(type, size, pos, separation, x_gap = 0, plain_idler_offset = [0, 0], upper_drive_pulley_offset = [0, 0], lower_drive_pulley_offset = [0, 0], 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)
@@ -195,10 +194,10 @@ module coreXY(type, size, pos, separation, x_gap, plain_idler_offset = 0, upper_
     }
 }
 
-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
+module coreXY_belts(type, carriagePosition, coreXYPosBL, coreXYPosTR, separation, x_gap = 0, plain_idler_offset = [0, 0], 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);
+        coreXY(type, coreXYSize, [carriagePosition.x - coreXYPosBL.x, carriagePosition.y - coreXYPosBL.y], separation, x_gap, plain_idler_offset, upper_drive_pulley_offset, lower_drive_pulley_offset, show_pulleys, left_lower);
 }

vitamins/belts.scad

@@ -30,6 +30,7 @@ T5x6 =  ["T",  5,    6, 2.2,  1.2,  0.5];
 T5x10 = ["T",  5,   10, 2.2,  1.2,  0.5];
 T2p5x6 =["T",  2.5,  6, 1.7,  0.7,  0.3];
 GT2x6 = ["GT", 2.0,  6, 1.38, 0.75, 0.254];
+GT2x9 = ["GT", 2.0,  9, 1.38, 0.75, 0.254];
 
-belts = [T5x6, T5x10, T2p5x6, GT2x6];
+belts = [T5x6, T5x10, T2p5x6, GT2x6, GT2x9];
 use <belt.scad>

vitamins/potentiometer.scad

@@ -27,21 +27,21 @@ pot_proud = 0.3;
 spigot_r = 0.5;
 tab = [3.2, 0.5];
 
-function pot_body(type)     = type[0];  //! Body diameter or width & depth, height and corner radius
-function pot_face(type)     = type[1];  //! Faceplate rib width, plate depth and plate height
-function pot_wafer(type)    = type[2];  //! Width, diameter and thickness of the track wafer plus true if curved
-function pot_gangs(type)    = type[3];  //! Number of gangs for mult-gang pot
-function pot_thread_d(type) = type[4];  //! Nomininal thread diameter
-function pot_thread_p(type) = type[5];  //! Thread pritch
-function pot_thread_h(type) = type[6];  //! Height of threaded part
-function pot_boss_d(type)   = type[7];  //! Boss diameter
-function pot_boss_h(type)   = type[8];  //! Boss height
-function pot_spigot(type)   = type[9];  //! Spigot width, length and height above the boss
-function pot_spigot_x(type) = type[10]; //! Spigot offset from the shaft centre
-function pot_shaft(type)    = type[11]; //! Diameter, flat diameter, length and flat/slot length and colour. If flat diameter is less than the radius then it is a slot width
-function pot_neck(type)     = type[12]; //! Diameter and length of the shaft neck
-function pot_nut(type)      = type[13]; //! Across flat diameter and thickness of the nut
-function pot_washer(type)   = type[14]; //! Outside diameter and thickness of the washer
+function pot_body(type)     = type[1];  //! Body diameter or width & depth, height and corner radius
+function pot_face(type)     = type[2];  //! Faceplate rib width, plate depth and plate height
+function pot_wafer(type)    = type[3];  //! Width, diameter and thickness of the track wafer plus true if curved
+function pot_gangs(type)    = type[4];  //! Number of gangs for mult-gang pot
+function pot_thread_d(type) = type[5];  //! Nomininal thread diameter
+function pot_thread_p(type) = type[6];  //! Thread pritch
+function pot_thread_h(type) = type[7];  //! Height of threaded part
+function pot_boss_d(type)   = type[8];  //! Boss diameter
+function pot_boss_h(type)   = type[9];  //! Boss height
+function pot_spigot(type)   = type[10]; //! Spigot width, length and height above the boss
+function pot_spigot_x(type) = type[11]; //! Spigot offset from the shaft centre
+function pot_shaft(type)    = type[12]; //! Diameter, flat diameter, length and flat/slot length and colour. If flat diameter is less than the radius then it is a slot width
+function pot_neck(type)     = type[13]; //! Diameter and length of the shaft neck
+function pot_nut(type)      = type[14]; //! Across flat diameter and thickness of the nut
+function pot_washer(type)   = type[15]; //! Outside diameter and thickness of the washer
 
 function pot_size(type) = let(d = pot_body(type)) len(d) > 3 ? [d.x , d.y, d.z] : [d.x, d.x, d.y]; //! Get pot body dimensions
 
@@ -86,7 +86,7 @@ module pot_nut(type, washer = true) { //! Draw the nut for a potentiometer and p
     }
 }
 
-module potentiometer(type, thickness = 3, shaft_length = undef) {//! Draw a potentiometer with nut spaced by specified thickness
+module potentiometer(type, thickness = 3, shaft_length = undef, value = false) {//! Draw a potentiometer with nut spaced by specified thickness
     bh = pot_boss_h(type);
     s = pot_size(type);
     face =  pot_face(type);
@@ -97,6 +97,7 @@ module potentiometer(type, thickness = 3, shaft_length = undef) {//! Draw a pote
     thread_d = pot_thread_d(type);
     thread_h = pot_thread_h(type);
     shaft = pot_shaft(type);
+    vitamin(str("potentiometer(", type[0], "): ", slice(type[0], start = -8) != "_encoder" ? "Potentiometer " : "", value ? value : type[0]));
 
     color(dia_cast_colour) {
         // Boss
@@ -210,7 +211,7 @@ module potentiometer(type, thickness = 3, shaft_length = undef) {//! Draw a pote
 
                 color(shaft[4])
                     vflip()
-                    cylinder(d = shaft.x, h = gap);
+                        cylinder(d = shaft.x, h = gap);
             }
         }
 

vitamins/potentiometers.scad

@@ -17,12 +17,12 @@
 // If not, see <https://www.gnu.org/licenses/>.
 //
 //! Potentiometers and rotary encoders
-//                 body     h     r     face               wafer                 gangs thread d  pitch       h     boss  h    spigot w, l, h  offset  shaft d flat d shaft h flat h colour neck   nut                  washer
-imperial_pot_x2 = [[24,     22.5, 1.5], [5.7, 15.33, 0.8], [20, 28, 1.6, true],  2,   inch(3/8), inch(1/32), 6.35, 13.6, 2.4, [1.12, 3.03, 2],    11, [6.27, 5.5, 44.3, 44.3, silver],   [0, 0],  [13.3, 2.4, brass],  [17.4, 0.8, grey(20), 9]];
-imperial_pot    = [[24,     12,   1.5], [5.7, 15.33, 0.8], [20, 28, 1.6, true],  1,   inch(3/8), inch(1/32), 6.35, 13.6, 2.4, [1.12, 3.03, 2],    11, [6.27, 5.5, 44.3, 44.3, grey(95)], [0, 0],  [13.3, 2.4, brass],  [17.4, 0.8, grey(20), 9]];
-metric_pot      = [[23,     11,   1.0], [0, 15.33, 0.8],   [18, 27, 1.2, false], 1,   10,        0.75,       7.32, 13.9, 2.5, [1.12, 2.88, 1.26], 11, [6.27, 5.5, 43.8, 43.5, grey(50)], [0, 0],  [12.8, 2,   silver], [17.7, 0.8, grey(20), 10]];
-KY_040_encoder  = [[12, 12, 6.5,  1.0], false,             false,                1,    7,        0.75,       7,    0,    0,   [0.4,  2,     0.8],5.8, [6,    4.5, 13,   10,   grey(60)], [4, 0.5],[9.8,  2.2, silver], [11.5, 0.4, silver]];
-BTT_encoder     = [[12, 11, 6,    0.5], false,             false,                1,    6,        0.8,        4.5,  0,    0,   false,               0, [5,    0.75, 9.5, 9,    silver],   [3, 0.5]];
+//                                    body     h     r     face               wafer                 gangs thread d  pitch       h     boss  h    spigot w, l, h  offset  shaft d flat d shaft h flat h colour neck   nut                  washer
+imperial_pot_x2 = ["imperial_pot_x2", [24,     22.5, 1.5], [5.7, 15.33, 0.8], [20, 28, 1.6, true],  2,   inch(3/8), inch(1/32), 6.35, 13.6, 2.4, [1.12, 3.03, 2],    11, [6.27, 5.5, 44.3, 44.3, silver],   [0, 0],  [13.3, 2.4, brass],  [17.4, 0.8, grey(20), 9]];
+imperial_pot    = ["imperial_pot",    [24,     12,   1.5], [5.7, 15.33, 0.8], [20, 28, 1.6, true],  1,   inch(3/8), inch(1/32), 6.35, 13.6, 2.4, [1.12, 3.03, 2],    11, [6.27, 5.5, 44.3, 44.3, grey(95)], [0, 0],  [13.3, 2.4, brass],  [17.4, 0.8, grey(20), 9]];
+metric_pot      = ["metric_pot",      [23,     11,   1.0], [0, 15.33, 0.8],   [18, 27, 1.2, false], 1,   10,        0.75,       7.32, 13.9, 2.5, [1.12, 2.88, 1.26], 11, [6.27, 5.5, 43.8, 43.5, grey(50)], [0, 0],  [12.8, 2,   silver], [17.7, 0.8, grey(20), 10]];
+KY_040_encoder  = ["KY_040_encoder",  [12, 12, 6.5,  1.0], false,             false,                1,    7,        0.75,       7,    0,    0,   [0.4,  2,     0.8],5.8, [6,    4.5, 13,   10,   grey(60)], [4, 0.5],[9.8,  2.2, silver], [11.5, 0.4, silver]];
+BTT_encoder     = ["BTT_encoder",     [12, 11, 6,    0.5], false,             false,                1,    6,        0.8,        4.5,  0,    0,   false,               0, [5,    0.75, 9.5, 9,    silver],   [3, 0.5]];
 
 potentiometers = [BTT_encoder, KY_040_encoder, metric_pot, imperial_pot, imperial_pot_x2];
 

vitamins/screw.scad

@@ -129,21 +129,26 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
         head_t = rad / 5;
         head_height = head_rad + head_t;
 
-        rotate_extrude()
-            difference() {
-                polygon([[0, 0], [head_rad, 0], [head_rad, -head_t], [0, -head_height]]);
-
-                translate([0, -socket_depth + eps])
-                    square([socket_rad, 10]);
-            }
-
-        translate_z(-socket_depth)
-            linear_extrude(socket_depth)
+        color(colour) {
+            rotate_extrude()
                 difference() {
-                    circle(socket_rad + 0.1);
+                    polygon([[0, 0], [head_rad, 0], [head_rad, -head_t], [0, -head_height]]);
 
-                    children();
+                    translate([0, -socket_depth + eps])
+                        square([socket_rad, 10]);
                 }
+
+            translate_z(-socket_depth)
+                linear_extrude(socket_depth)
+                    difference() {
+                        circle(socket_rad + 0.1);
+
+                        children();
+                    }
+        }
+        color(colour * 0.9)
+            translate_z(-socket_depth)
+                cylinder(h=2 * eps, r=socket_rad, $fn = 6);
     }
 
     explode(length + 10) {
@@ -160,6 +165,9 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                         }
 
             }
+            color(colour * 0.9)
+                translate_z(head_height - socket_depth)
+                    cylinder(h=2 * eps, r=socket_rad, $fn = 6);
             shaft();
         }
         if(head_type == hs_grub) {
@@ -179,6 +187,9 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                     translate_z(-length)
                         cylinder(r = r, h = length - socket_depth);
             }
+            color(colour * 0.8)
+                translate_z(head_height - socket_depth)
+                    cylinder(h=2 * eps, r=socket_rad, $fn = 6);
         }
         if(head_type == hs_hex) {
             color(colour)
@@ -207,6 +218,9 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                         square([socket_width, 2 * socket_rad], center = true);
                     }
             }
+            color(colour * 0.9)
+                translate_z(head_height - socket_depth)
+                    cylinder(h=2 * eps, r=socket_rad + eps);
             shaft();
         }
 
@@ -234,6 +248,9 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                         circle(socket_rad, $fn = 6);
                     }
             }
+            color(colour * 0.9)
+                translate_z(head_height - socket_depth)
+                    cylinder(h=2 * eps, r=socket_rad, $fn = 6);
             shaft();
         }
 
@@ -241,19 +258,17 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
             socket_rad = 0.6 * head_rad;
             socket_depth = 0.3 * head_rad;
             socket_width = 1;
-            color(colour)
-                cs_head(socket_rad, socket_depth) {
-                    square([2 * socket_rad, socket_width], center = true);
-                    square([socket_width, 2 * socket_rad], center = true);
-                }
+            cs_head(socket_rad, socket_depth) {
+                square([2 * socket_rad, socket_width], center = true);
+                square([socket_width, 2 * socket_rad], center = true);
+            }
 
             shaft(socket_depth);
         }
 
         if(head_type == hs_cs_cap) {
-            color(colour)
-                cs_head(socket_rad, socket_depth)
-                    circle(socket_rad, $fn = 6);
+            cs_head(socket_rad, socket_depth)
+                circle(socket_rad, $fn = 6);
 
             shaft(socket_depth);
         }