Adafruit Feather 405 contributed by Chris Lott.

This change adds
- SBR rails. For now only SBR16
- The bearing block that goes with it (SBR16UU)
- An 'open' linear bearing (LM16UUOP) that is used by the bearing block
- A 28mm circlip that has a wider opening than then normal circlip.
(circlip_28iw)

CHANGELOG.md

@@ -3,6 +3,47 @@
 This changelog is generated by `changelog.py` using manually added semantic version tags to classify commits as breaking changes, additions or fixes.
 
 
+### [v21.6.0](https://github.com/nophead/NopSCADlib/releases/tag/v21.6.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v21.5.1...v21.6.0 "diff with v21.5.1")
+*   2023-07-22 [`e3cde64`](https://github.com/nophead/NopSCADlib/commit/e3cde64b61b6abfc4a2883e8aa32b66346fde1c4 "show commit") [C.](# "Chris") `open_bearing_theta()` now derived from `open_bearing_width()`.
+
+*   2023-07-22 [`e61ce02`](https://github.com/nophead/NopSCADlib/commit/e61ce0241443fb2c1f0585953bd3f7383b217086 "show commit") [C.](# "Chris") Moved things around for better test images.
+
+*   2023-07-22 [`f8e1256`](https://github.com/nophead/NopSCADlib/commit/f8e125654ed60842d6ca7f33a91377d9cb5f1dc9 "show commit") [C.](# "Chris") Rendred the 3D difference.
+
+*   2023-07-22 [`62b1511`](https://github.com/nophead/NopSCADlib/commit/62b1511c82eacb5124302aed36a52fe0d8104385 "show commit") [C.](# "Chris") Removed 3D difference for speed.
+
+*   2023-06-27 [`84d98a1`](https://github.com/nophead/NopSCADlib/commit/84d98a1081d38c56d5b02645a99223b7616fcd70 "show commit") [J.R.](# "Jeroen Roos") Added SBR rails
+
+ * This change adds
+- SBR rails. For now only SBR16
+- The bearing block that goes with it (SBR16UU)
+- An 'open' linear bearing (LM16UUOP) that is used by the bearing block
+- A 28mm circlip that has a wider opening than then normal circlip.
+`(circlip_28iw)`
+
+#### [v21.5.1](https://github.com/nophead/NopSCADlib/releases/tag/v21.5.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v21.5.0...v21.5.1 "diff with v21.5.0")
+*   2023-06-29 [`5899ffe`](https://github.com/nophead/NopSCADlib/commit/5899ffe88f7952108ce928a5a6188b4aad5044c5 "show commit") [C.](# "Chris") More typos in comments.
+
+*   2023-06-28 [`b051311`](https://github.com/nophead/NopSCADlib/commit/b05131145caf500cd9198b1e9b9fafc69506b50f "show commit") [C.](# "Chris") Comment typo.
+
+### [v21.5.0](https://github.com/nophead/NopSCADlib/releases/tag/v21.5.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v21.4.1...v21.5.0 "diff with v21.4.1")
+*   2023-05-08 [`c3f3d62`](https://github.com/nophead/NopSCADlib/commit/c3f3d629b1ff79d40cc5ad3efcb33e940d6c8056 "show commit") [C.P.](# "Chris Palmer") Added PanelDue V3.
+
+*   2023-05-08 [`c7ba052`](https://github.com/nophead/NopSCADlib/commit/c7ba052ccf24d764aa6460d4559e92596c9e4cf4 "show commit") [C.P.](# "Chris Palmer") Added SMD QFP package.
+
+*   2023-05-08 [`c2c5f50`](https://github.com/nophead/NopSCADlib/commit/c2c5f509860b909ca8fca5ffcc65dbef2f7177c5 "show commit") [C.P.](# "Chris Palmer") Can now used `smd_res()` to draw chokes.
+
+*   2023-05-08 [`d0ae8ca`](https://github.com/nophead/NopSCADlib/commit/d0ae8ca216108f53c9b8e60896ea9b59b845b7e0 "show commit") [C.P.](# "Chris Palmer") Added the ability to have more than one grid on a PCB.
+
+*   2023-05-08 [`e81dcfd`](https://github.com/nophead/NopSCADlib/commit/e81dcfdbd8163ce8e2db450f3a20c296c21327a8 "show commit") [C.P.](# "Chris Palmer") Added right angle option to box headers.
+
+#### [v21.4.1](https://github.com/nophead/NopSCADlib/releases/tag/v21.4.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v21.4.0...v21.4.1 "diff with v21.4.0")
+*   2023-05-08 [`06a286d`](https://github.com/nophead/NopSCADlib/commit/06a286dc989e9cc8cf7918049cd16a862b1a9b94 "show commit") [C.P.](# "Chris Palmer") Fixed missing BOM entry for JST connectors.
+Fixed default colour for JST connectors.
+Corrected BOM entry to show right angle options on Molex and pin headers.
+
+*   2023-05-08 [`f5496c3`](https://github.com/nophead/NopSCADlib/commit/f5496c373a1ab8ae47d07cc0a52d76e4299876cc "show commit") [C.P.](# "Chris Palmer") Fixed typo in `smd_diode(DO214AC)` package name.
+
 ### [v21.4.0](https://github.com/nophead/NopSCADlib/releases/tag/v21.4.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v21.3.1...v21.4.0 "diff with v21.3.1")
 *   2023-05-01 [`5e24a32`](https://github.com/nophead/NopSCADlib/commit/5e24a32a0b422e8032c3c5d377c1a756ff6f1022 "show commit") [C.P.](# "Chris Palmer") Added ESP32 camera.
 
@@ -66,8 +107,6 @@ This changelog is generated by `changelog.py` using manually added semantic vers
 
 *   2023-02-01 [`abf1f1a`](https://github.com/nophead/NopSCADlib/commit/abf1f1ab3f3eddc2f274df649e8481a4117901eb "show commit") [C.P.](# "Chris Palmer") PCB blocks can now have rounded edges for more realistic cans.
 
-*   2023-02-01 [`df06d1f`](https://github.com/nophead/NopSCADlib/commit/df06d1f57fff64cd6da20684f8371da204f69a82 "show commit") [C.P.](# "Chris Palmer") Updated changelog.
-
 ### [v20.23.0](https://github.com/nophead/NopSCADlib/releases/tag/v20.23.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v20.22.0...v20.23.0 "diff with v20.22.0")
 *   2023-02-01 [`470d6d6`](https://github.com/nophead/NopSCADlib/commit/470d6d6216b1cef8ce6cafd4b14300edb62eac4a "show commit") [C.P.](# "Chris Palmer") Started radial components with crystals.
 
@@ -109,7 +148,7 @@ This changelog is generated by `changelog.py` using manually added semantic vers
 *   2023-01-24 [`77e948f`](https://github.com/nophead/NopSCADlib/commit/77e948f43c911442211bcbf6d1b1520184d2c70b "show commit") [C.P.](# "Chris Palmer") Added can bus connectors to OpenGrab model.
 Tweaked some PCB component positions.
 
-*   2023-01-24 [`543cdb4`](https://github.com/nophead/NopSCADlib/commit/543cdb4e01d38308a06d4368ebabadb85c696567 "show commit") [C.P.](# "Chris Palmer") Incresed the clearance of holes made for pin header.
+*   2023-01-24 [`543cdb4`](https://github.com/nophead/NopSCADlib/commit/543cdb4e01d38308a06d4368ebabadb85c696567 "show commit") [C.P.](# "Chris Palmer") Increased the clearance of holes made for pin header.
 
 ### [v20.19.0](https://github.com/nophead/NopSCADlib/releases/tag/v20.19.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v20.18.1...v20.19.0 "diff with v20.18.1")
 *   2023-01-12 [`ebd50ba`](https://github.com/nophead/NopSCADlib/commit/ebd50bae535283b94b310ee74c9b98b2e3b7f8be "show commit") [C.P.](# "Chris Palmer") Added SMD diodes, inductors and potentiometers.
@@ -144,8 +183,6 @@ Client code now calls `dxf()` so that the generated files can be used to speed u
 
  * Change comment about nut sizes from radius to diameter.
 
-*   2022-09-29 [`d95e1e6`](https://github.com/nophead/NopSCADlib/commit/d95e1e64edba4ef51852a1e72d00497154c80c88 "show commit") [C.](# "Chris") Udated changelog.
-
 ### [v20.14.0](https://github.com/nophead/NopSCADlib/releases/tag/v20.14.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v20.13.0...v20.14.0 "diff with v20.13.0")
 *   2022-09-29 [`f1737d2`](https://github.com/nophead/NopSCADlib/commit/f1737d257b54957772ab6faea102f8ddb829119b "show commit") [C.](# "Chris") Updated images and readme.
 
@@ -545,7 +582,7 @@ Lead length removed from TO220 and TO247 vitamin string.
 Mainly text spacing changes.
 
 *   2021-09-27 [`9b5ec6a`](https://github.com/nophead/NopSCADlib/commit/9b5ec6af1aba313df6812a5313470ebb7e8fbdd7 "show commit") [C.P.](# "Chris Palmer") Fixed new `rounded_polygon` to work with last OpenSCAD release.
-Trainling commas in `let()`.
+Trailing commas in `let()`.
 
 *   2021-09-27 [`50958b0`](https://github.com/nophead/NopSCADlib/commit/50958b064d5a6d5ca3fd6525a8c3d3a2c5b20199 "show commit") [C.P.](# "Chris Palmer") Added `$show_plugs` to show crude reprentations of housings on `pin_headers` and Molex KK headers.
 
@@ -1207,7 +1244,7 @@ Updated pics and readme.
 *   2020-12-28 [`f6f4fcc`](https://github.com/nophead/NopSCADlib/commit/f6f4fcc7e84e40669446708e2352ea68c49b7961 "show commit") [M.B.](# "Martin Budden") Added `M5_cs_cap` screw
 
 #### [v10.21.1](https://github.com/nophead/NopSCADlib/releases/tag/v10.21.1 "show release") Fixes [...](https://github.com/nophead/NopSCADlib/compare/v10.21.0...v10.21.1 "diff with v10.21.0")
-*   2020-12-28 [`ba586b3`](https://github.com/nophead/NopSCADlib/commit/ba586b368582db163af143ebb60afed270f77b1c "show commit") [C.P.](# "Chris Palmer") Example images update to match new contersink screws and teardrops.
+*   2020-12-28 [`ba586b3`](https://github.com/nophead/NopSCADlib/commit/ba586b368582db163af143ebb60afed270f77b1c "show commit") [C.P.](# "Chris Palmer") Example images update to match new countersink screws and teardrops.
 
 ### [v10.21.0](https://github.com/nophead/NopSCADlib/releases/tag/v10.21.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v10.20.1...v10.21.0 "diff with v10.20.1")
 *   2020-12-28 [`8d22940`](https://github.com/nophead/NopSCADlib/commit/8d22940506df525ac52ef6f8a00ea03661f3b682 "show commit") [C.P.](# "Chris Palmer") Project blurb can now be split with into sections with markdown horizontal rules
@@ -1485,7 +1522,7 @@ Reverted the jst header pin position change.
 
 *   2020-09-20 [`933fea6`](https://github.com/nophead/NopSCADlib/commit/933fea687c54d7d8ec48fe92aae12ffca0666789 "show commit") [C.P.](# "Chris Palmer") Removed debug code
 
-*   2020-09-19 [`a7803b1`](https://github.com/nophead/NopSCADlib/commit/a7803b1efbf92c5e27f3171d7e2a92634fa2d84f "show commit") [C.P.](# "Chris Palmer") Improved numerical accuarcy of catenary calculations.
+*   2020-09-19 [`a7803b1`](https://github.com/nophead/NopSCADlib/commit/a7803b1efbf92c5e27f3171d7e2a92634fa2d84f "show commit") [C.P.](# "Chris Palmer") Improved numerical accuracy of catenary calculations.
 
 ### [v9.7.0](https://github.com/nophead/NopSCADlib/releases/tag/v9.7.0 "show release") Additions [...](https://github.com/nophead/NopSCADlib/compare/v9.6.1...v9.7.0 "diff with v9.6.1")
 *   2020-09-19 [`1255e71`](https://github.com/nophead/NopSCADlib/commit/1255e712719ce66fd3b231e5c212ea69b0bb9f1c "show commit") [C.P.](# "Chris Palmer") Added catenary curves.

libtest.scad

@@ -96,6 +96,7 @@ use <tests/rails.scad>
 use <tests/ring_terminals.scad>
 use <tests/rockers.scad>
 use <tests/rod.scad>
+use <tests/SBR_rails.scad>
 use <tests/screws.scad>
 use <tests/sealing_strip.scad>
 use <tests/servo_motors.scad>
@@ -144,7 +145,7 @@ x1 = x0 + 110;
 x2 = x1 + 90;
 x3 = x2 + 130;
 x4 = x3 + 200;
-x5 = 850;
+x5 = 900;
 x6 = x5 + 150;
 
 cable_grommets_y = 0;
@@ -233,8 +234,8 @@ tubings_y = sealing_strip_y + 20;
 pillars_y = tubings_y + 20;
 ball_bearings_y = pillars_y + 40;
 pulleys_y = ball_bearings_y + 40;
-leadnuts_y = pulleys_y + 60;
-linear_bearings_y = leadnuts_y + 50;
+leadnuts_y = pulleys_y + 35;
+linear_bearings_y = leadnuts_y + 65;
 steppers_y = linear_bearings_y + 110;
 sheets_y = steppers_y + 55;
 pcbs_y = sheets_y + 60;
@@ -289,7 +290,9 @@ translate([x0 + 120, leadnuts_y])
     leadnuthousings();
 
 translate([x0, linear_bearings_y]) {
-    linear_bearings();
+    translate([0, -30])
+        linear_bearings();
+
     rods();
 }
 
@@ -397,7 +400,7 @@ blowers_y = ssrs_y + 60;
 hot_ends_y = blowers_y + 100;
 batteries_y = hot_ends_y + 55;
 panel_meters_y = batteries_y + 70;
-extrusions_y = panel_meters_y + 80;
+extrusions_y = panel_meters_y + 100;
 
 translate([x3, veroboard_y])
     veroboard_test();
@@ -465,11 +468,11 @@ rails_y = belts_y + 200;
 extrusion_brackets_y = rails_y + 250;
 sk_brackets_y = extrusion_brackets_y + 80;
 kp_pillow_blocks_y = sk_brackets_y + 60;
-scs_bearing_blocks_y = kp_pillow_blocks_y + 60;
+bearing_blocks_y = kp_pillow_blocks_y + 60;
 box_sections_y = batteries_y;
-BLDC_y = scs_bearing_blocks_y + 120;
-pot_y = BLDC_y + 40;
-cable_strip_y = pot_y + 50;
+BLDC_y = bearing_blocks_y + 180;
+pot_y = bearing_blocks_y;
+cable_strip_y = sheets_y + 30;
 
 translate([0, transformers_y])
     servo_motors();
@@ -484,9 +487,13 @@ translate([x4 + 200, belts_y + 58]) {
 translate([x4 + 175, belts_y, -20])
     drag_chains();
 
-translate([x4, rails_y + 130])
+translate([x4, rails_y + 130]) {
     rails();
 
+    translate([305, 0])
+        sbr_rails();
+}
+
 translate([x4, cable_strip_y])
     cable_strips();
 
@@ -502,8 +509,8 @@ translate([x4, extrusion_brackets_y])
 translate([x1, swiss_clips_y + 50])
     shaft_couplings();
 
-translate([x4, scs_bearing_blocks_y])
-    scs_bearing_blocks();
+translate([x4, bearing_blocks_y])
+    bearing_blocks();
 
 translate([x4, BLDC_y])
     bldc_motors();

scripts/changelog.py

@@ -80,9 +80,16 @@ def codify(word, url):
             return  '`' + word + '`'
     return word
 
+typos = [ # Typos that are ambiguous to codespell
+    ('cnc_bit+_r', 'cnc_bit_r'),
+    ('Udated',     'Updated'),
+    ('decription', 'description'),
+    ('Trainling',  'Trailing'),
+]
 
 def fixup_comment(comment, url):
-    comment = comment.replace('cnc_bit+_r', 'cnc_bit_r')
+    for typo in typos:
+        comment = comment.replace(typo[0], typo[1])
     """ markup code words and fix new paragraphs """
     result = ''
     word = ''
@@ -162,6 +169,6 @@ 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 ch.*log.*', c.comment):
+            if not c.comment.startswith('Merge branch') and not c.comment.startswith('Merge pull') and not re.match(r'U.?.ated ch.*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())

scripts/tests.py

@@ -201,7 +201,7 @@ def tests(tests):
             body = bodies[type]
 
             index[type] += [cap_name]
-            body += ['<a name="%s"></a>' % cap_name]
+            body += ['<a name="%s"></a>' % cap_name.lower()]
             body += ["## " + cap_name]
 
             doc = None
@@ -301,7 +301,7 @@ def tests(tests):
             for type in types:
                 if i < len(index[type]):
                     name = sorted(index[type])[i]
-                    print('<td> <a href = "#' + name + '">' + name + '</a> </td>', file = doc_file, end = '')
+                    print('<td> <a href = "#' + name.lower() + '">' + name + '</a> </td>', file = doc_file, end = '')
                 else:
                     print('<td></td>', file = doc_file, end = '')
             print('</tr>', file = doc_file)

tests/SBR_rails.scad

@@ -0,0 +1,46 @@
+//
+// NopSCADlib Copyright Chris Palmer 2023
+// 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/sbr_rails.scad>
+
+use <../utils/layout.scad>
+use <../vitamins/bearing_block.scad>
+
+length = 200;
+sheet = 3;
+
+module sbr_rails()
+    layout([for(r = sbr_rails) sbr_rail_base_width(r)], 10)
+        rotate([90, 180,0]) {
+            rail = sbr_rails[$i];
+            sbr_rail(rail, length);
+            carriage = sbr_rail_carriage(rail);
+            screw = sbr_rail_screw(rail);
+
+            sbr_bearing_block_assembly(carriage, sheet);
+
+            sbr_screw_positions(rail, length)
+                explode(20)
+                    rotate([90,0,0])
+                        screw(sbr_rail_screw(rail), 18);
+
+         }
+
+if($preview)
+    sbr_rails();

tests/bearing_blocks.scad

@@ -24,12 +24,26 @@ use <../utils/layout.scad>
 module scs_bearing_blocks()
     layout([for(s = scs_bearing_blocks) scs_size(s).x], 10) {
         part_thickness = 5;
-        scs_bearing_block_assembly(scs_bearing_blocks[$i], part_thickness);
+        translate([0, 60])
+            scs_bearing_block_assembly(scs_bearing_blocks[$i], part_thickness);
 
         if($i > 0) // skip $i==0, since no SCS6LUU long variant to match SCS6UU
-            translate([0, 60])
+            translate([0, 120])
                 scs_bearing_block_assembly(scs_bearing_blocks_long[$i - 1], part_thickness);
     }
 
-if($preview)
+module sbr_bearing_blocks()
+    layout([for(s = sbr_bearing_blocks) sbr_size(s).x], 10) {
+        part_thickness = 5;
+        sbr_bearing_block_assembly(sbr_bearing_blocks[$i], part_thickness);
+    }
+
+module bearing_blocks() {
     scs_bearing_blocks();
+
+    translate([190, 0])
+        sbr_bearing_blocks();
+}
+
+if($preview)
+    bearing_blocks();

tests/circlips.scad

@@ -22,7 +22,7 @@ use <../utils/layout.scad>
 include <../vitamins/circlips.scad>
 
 module circlips(all = false)
-    layout([for(c = circlips) circlip_d3(c)], 10, false) let(c = circlips[$i]) {
+    layout([for(c = circlips) circlip_d3(c)], 5, false) let(c = circlips[$i]) {
         gap = circlip_d3(c) + 2;
 
         internal_circlip(c, 1);

tests/linear_bearings.scad

@@ -21,13 +21,18 @@ use <../utils/layout.scad>
 
 include <../vitamins/linear_bearings.scad>
 
-module linear_bearings()
+module linear_bearings() {
     layout([for(b = linear_bearings) 2 * bearing_radius(b)]) {
-        linear_bearing(linear_bearings[$i]);
-
         translate([0, 30])
+            linear_bearing(linear_bearings[$i]);
+
+        translate([0, 60])
             linear_bearing(long_linear_bearings[$i]);
     }
+    layout([for(b = open_linear_bearings) 2 * bearing_radius(b)])
+        translate([105, 0])
+            linear_bearing(open_linear_bearings[$i]);
+}
 
 if($preview)
     linear_bearings();

utils/maths.scad

@@ -104,7 +104,7 @@ function reverse(v) = let(n = len(v) - 1) n < 0 ? [] : [for(i = [0 : n]) v[n - i
 function angle_between(v1, v2) = acos(v1 * v2 / (norm(v1) * norm(v2))); //! Return the angle between two vectors
 
 // http://eecs.qmul.ac.uk/~gslabaugh/publications/euler.pdf
-function euler(R) = let(ay = asin(-R[2][0]), cy = cos(ay)) //! Convert a rotation matrix to a Euler rotation vector.
+function euler(R) = let(ay = asin(-R[2][0]), cy = cos(ay)) //! Convert a rotation matrix to an Euler rotation vector.
     cy ? [ atan2(R[2][1] / cy, R[2][2] / cy), ay, atan2(R[1][0] / cy, R[0][0] / cy) ]
        : R[2][0] < 0 ? [atan2( R[0][1],  R[0][2]),  90, 0]
                      : [atan2(-R[0][1], -R[0][2]), -90, 0];

vitamins/bearing_block.scad

@@ -41,6 +41,17 @@ function scs_circlip(type)              = type[15]; //! Circlip used
 function scs_spacer(type)               = type[16]; //! Spacer used in long bearings
 
 
+function sbr_size(type)                 = [type[4],type[6],type[5]]; //! Size of SBR bracket bounding block
+function sbr_hole_offset(type)          = type[2]; //! Offset of bearing hole from base of *rail*
+function sbr_side_height(type)          = type[3]; //! Height of side above *rail*
+function sbr_screw(type)                = type[10]; //! Screw type
+function sbr_screw_separation_x(type)   = type[7];  //! Screw separation in X direction
+function sbr_screw_separation_z(type)   = type[8];  //! Screw separation in Z direction
+function sbr_bearing(type)              = type[12]; //! Linear bearing used
+function sbr_circlip(type)              = type[13]; //! Circlip used
+function sbr_spacer(type)               = type[14]; //! Spacer used in long bearings
+
+
 sks_bearing_block_colour = grey(90);
 
 module scs_bearing_block(type) { //! Draw the specified SCS bearing block
@@ -63,11 +74,6 @@ module scs_bearing_block(type) { //! Draw the specified SCS bearing block
     bearing = scs_bearing(type);
     clip = scs_circlip(type);
 
-    module right_trapezoid(base, top, height, h = 0, center = true) {//! A right angled trapezoid with the 90° corner at the origin. 3D when `h` is nonzero, otherwise 2D
-        extrude_if(h, center = center)
-            polygon(points = [ [0,0], [base, 0], [top, height], [0, height] ]);
-    }
-
     boltHoleRadius = screw_clearance_radius(S1);
     footHeight = min(0.75, (G - bearing_dia(bearing) - 1.5) / 2); // estimate, not specified on drawings
 
@@ -169,3 +175,142 @@ module scs_bearing_block_assembly(type, part_thickness, screw_type, nut_type) {
                     washer(washer_type);
     }
 }
+
+/* SBR bearing blocks */
+
+module sbr_bearing_block(type) { //! Draw the specified SBR bearing block
+    vitamin(str("sbr_bearing_block(", type[0], "): ", type[0], " bearing block"));
+
+    T = type[1];
+    h = sbr_hole_offset(type);
+    H = sbr_side_height(type);
+
+    W = sbr_size(type)[0];
+    G = sbr_size(type)[1];
+    M = sbr_size(type)[2];
+    J = sbr_screw_separation_x(type);
+    K = sbr_screw_separation_z(type);
+    S1 = sbr_screw(type);
+    I = type[11];           // screw length
+
+    S2 = type[15];
+    S2L = type[16];
+
+    bearing = sbr_bearing(type);
+    clip = sbr_circlip(type);
+    chamfer = 1.5;
+    A = type[9];            // size of chamfered overhang - vertical
+    Ah = A + chamfer * 2;   // size of chamfered overhand - horizontal - not given in drawings
+
+    width = W - (2 * chamfer);
+    height = G - chamfer;
+
+    boltHoleRadius = screw_radius(S1);
+    setScrewRadius = screw_radius(S2);
+
+    color(sks_bearing_block_colour) {
+        render() difference() {
+            linear_extrude(M, center = true, convexity=2) {
+                cutoutheight = 15; // chosen to fit SBR16, may not work with others
+                bearingRadius = bearing_dia(bearing) / 2;
+                bearingTheta = open_bearing_theta(bearing);
+                bearingOpening = open_bearing_width(bearing);
+                bearingOpeningBig = bearingOpening + (tan(bearingTheta/2) * cutoutheight);
+                // center section with bearing hole
+                difference() {
+                    translate([-width/2, -(H-h - chamfer)])
+                        square([width, height]);
+                    circle(r = bearingRadius);
+                    for(m = [0, 1])
+                        mirror([m, 0, 0])
+                            translate([0, h - (cutoutheight/2) - H + G + 0.1])
+                                right_trapezoid(bearingOpening/2, bearingOpeningBig/2, cutoutheight/2);
+                }
+                // add the sides
+                for(m = [0, 1])
+                    mirror([m, 0, 0]) {
+                        translate([-(W/2) + chamfer, -((H-h))]) {
+                            difference() {
+                                union() {
+                                    right_trapezoid(Ah - chamfer,Ah,chamfer);
+                                    rotate([0,0,90])
+                                        right_trapezoid(A + chamfer,A,chamfer);
+                                }
+                                translate([-(chamfer +0.1), -0.1,0])
+                                    right_trapezoid(chamfer/2 + 0.2, 0, chamfer/2+ 0.2);
+                            }
+                        }
+                    }
+            }
+            // bolt holes
+            for(x = [-J / 2, J / 2])
+                translate([x, h - H + I/2 - 0.1, 0])
+                    rotate([90, 0, 0])
+                        for (y = [-K / 2, K / 2])
+                            translate([0, y])
+                                cylinder(r = boltHoleRadius, h=I + 0.1, center=true);
+
+            // set screw holes
+            translate([-width/2 + S2L/2 - 0.1,0,0])
+                rotate([0,90,0])
+                    cylinder(r = setScrewRadius, h=S2L, center=true);
+
+            translate([0,-(H-h) + chamfer + S2L/2 -0.1,0])
+                rotate([0,90,90])
+                    cylinder(r = setScrewRadius, h=S2L, center=true);
+
+        }
+    }
+    not_on_bom() no_explode() {
+        spacer = sbr_spacer(type);
+        for(end = spacer ? [-1, 1] : 0)
+            translate_z(end * (bearing_length(bearing) + spacer) / 2)
+                rotate([0,0,-90])
+                    linear_bearing(bearing);
+
+        for(end = [-1, 1])
+            translate_z(end * ((spacer ? 2 * bearing_length(bearing) + spacer : bearing_length(bearing)) + circlip_thickness(clip)) / 2)
+                rotate(180)
+                    internal_circlip(clip);
+
+        translate([-width/2 - 0.1,0,0])
+            rotate([0,90,180])
+               screw(S2, S2L);
+        translate([0,-(H-h) + chamfer - 0.1,0])
+            rotate([0,90,270])
+                screw(S2, S2L);
+    }
+}
+
+module sbr_bearing_block_hole_positions(type) { //! Place children at hole positions
+    y = sbr_hole_offset(type) - sbr_side_height(type);
+    screw_separation_x = sbr_screw_separation_x(type);
+    screw_separation_z = sbr_screw_separation_z(type);
+
+    for(x = [-screw_separation_x, screw_separation_x], z = [-screw_separation_z, screw_separation_z])
+        translate([x / 2, y, z / 2])
+            rotate([-90, 0, 0])
+                children();
+}
+
+module sbr_bearing_block_assembly(type, part_thickness, screw_type) { //! Assembly with screws in place
+
+    I = type[11]; // screw length
+    sbr_bearing_block(type);
+    screw_type = is_undef(screw_type) ? sbr_screw(type) : screw_type;
+    G = sbr_size(type)[1];
+
+    screw_length = screw_shorter_than(I + part_thickness);
+
+    translate([0,-part_thickness,0])
+        sbr_bearing_block_hole_positions(type)
+            rotate([0,180,0])
+                screw(screw_type, screw_length);
+}
+
+/* Generic bearing block functions */
+
+module right_trapezoid(base, top, height, h = 0, center = true) {//! A right angled trapezoid with the 90° corner at the origin. 3D when `h` is nonzero, otherwise 2D
+    extrude_if(h, center = center)
+        polygon(points = [ [0,0], [base, 0], [top, height], [0, height] ]);
+}

vitamins/bearing_blocks.scad

@@ -36,8 +36,12 @@ SCS10LUU  = ["SCS10LUU",  8, 13, 20, 40, 68, 26,   21, 28,   45, 6,    M5_cap_sc
 SCS12LUU  = ["SCS12LUU",  8, 15, 21, 42, 70, 28,   24, 30.5, 50, 5.75, M5_cap_screw, 4.3, 12, LM12UU, circlip_21i, 4];
 SCS16LUU  = ["SCS16LUU",  9, 19, 25, 50, 85, 38.5, 32.5, 36, 60, 7,    M5_cap_screw, 4.3, 12, LM16UU, circlip_28i, 4];
 
+//                        T  h   H   W   M   G     J   K   A  S1            I   LB                         S2             S2L
+SBR16UU   = ["SBR16UU",  16, 25, 45, 45, 45, 33,   32, 30, 9, M5_cap_screw, 12, LM16UUOP, circlip_28iw, 0, M5_grub_screw, 5];
 
 scs_bearing_blocks = [SCS6UU, SCS8UU,  SCS10UU, SCS12UU, SCS16UU];
 scs_bearing_blocks_long = [SCS8LUU,  SCS10LUU, SCS12LUU, SCS16LUU];
 
+sbr_bearing_blocks = [SBR16UU];
+
 use <bearing_block.scad>

vitamins/circlip.scad

@@ -32,14 +32,14 @@ function circlip_thickness(type) = type[4];     //! Thickness
 function circlip_a(type)         = type[5];     //! Size of the lugs
 function circlip_b(type)         = type[6];     //! Widest part of the taper
 function circlip_d5(type)        = type[7];     //! Plier hole diameter
+function circlip_closed_angle(type)    = is_undef(type[8]) ? 25 : type[8];     //! Closed angle
 
 circlip_colour = grey(20);
-closed_angle = 25;
 
 module internal_circlip(type, open = 0) { //! Draw specified internal circlip, open = 0, for nominal size installed, 1 for relaxed uninstalled, -1 for squeezed to install
     d1 = circlip_d1(type);
-
-    vitamin(str("circlip(", type[0], "): Circlip internal ", d1, "mm"));
+    wide = is_undef(type[8]) ? "" : " (wide opening)";
+    vitamin(str("circlip(", type[0], "): Circlip internal ", d1, "mm",wide));
     d3 = circlip_d3(type);
     d2 = circlip_d2(type);
     a = circlip_a(type);
@@ -50,7 +50,7 @@ module internal_circlip(type, open = 0) { //! Draw specified internal circlip, o
     or = od / 2;
     c = (d3 - d1);
 
-    angle = (od - d1) / d1 * 360 + closed_angle;
+    angle = (od - d1) / d1 * 360 + circlip_closed_angle(type);
     tab_angle = 360 * a / PI / od;
     p = [0, -or + b / 2, 1] * rot3_z(angle / 2 + tab_angle);
     pitch = (or - a / 2);

vitamins/circlips.scad

@@ -22,7 +22,8 @@ circlip_15i = ["circlip_15i", 15, 15.7, 16.2, 1.0, 3.7, 2.0, 1.7];
 circlip_19i = ["circlip_19i", 19, 20.0, 20.5, 1.0, 4.1, 2.2, 2.0];
 circlip_21i = ["circlip_21i", 21, 22.0, 22.5, 1.0, 4.2, 2.4, 2.0];
 circlip_28i = ["circlip_28i", 28, 29.4, 30.1, 1.2, 4.8, 2.9, 2.0];
+circlip_28iw = ["circlip_28iw", 28, 29.4, 30.1, 1.2, 4.8, 2.9, 2.0, 100]; // with wide opening
 
-circlips = [circlip_12i, circlip_15i, circlip_19i, circlip_21i, circlip_28i];
+circlips = [circlip_12i, circlip_15i, circlip_19i, circlip_21i, circlip_28i, circlip_28iw];
 
 use <circlip.scad>

vitamins/linear_bearing.scad

@@ -23,6 +23,7 @@
 include <../utils/core/core.scad>
 
 use <../utils/tube.scad>
+use <../utils/sector.scad>
 
 bearing_colour = grey(70);
 groove_colour = grey(60);
@@ -36,6 +37,10 @@ function bearing_groove_length(type)    = type[4];   //! Groove length
 function bearing_groove_dia(type)       = type[5];   //! Groove diameter
 function bearing_groove_spacing(type)   = type[6];   //! Spacing between grooves, outer to outer, ie includes the grooves themselves
 
+function open_bearing_width(type)       = type[7]; //! For open bearings, the width of the opening at the rod
+function open_bearing_theta(type)       = 2 * asin(open_bearing_width(type) / bearing_rod_dia(type)); //! For open bearings, the angle of the opening
+
+
 function bearing_radius(type)  = bearing_dia(type) / 2; //! Outside radius
 
 module linear_bearing(type) { //! Draw specified linear bearing
@@ -50,21 +55,34 @@ module linear_bearing(type) { //! Draw specified linear bearing
     gs = bearing_groove_spacing(type);
     offset = (length-gs)/2;
 
+    module cut_tube(or, ir, h, center = true)
+        linear_extrude(h, center = center, convexity = 5)
+            difference() {
+                ring(or = or, ir = ir);
+
+                // Open bearing
+                if (!is_undef(type[7])) {
+                    theta = open_bearing_theta(type);
+
+                    sector(or + 1, 180 - theta / 2, 180 + theta / 2);
+                }
+            }
+
     if(gs==0) {
         color(bearing_colour) tube(or = or, ir = casing_ir, h = length);
     } else {
         translate_z(-length/2) {
-            color(bearing_colour) tube(or = or, ir = casing_ir, h = offset, center = false);
-            color(groove_colour) translate_z(offset) tube(or = gr, ir = casing_ir, h = gl,center = false);
-            color(bearing_colour) translate_z(offset+gl) tube(or = or, ir = casing_ir, h = gs-2*gl, center = false);
-            color(groove_colour) translate_z(offset+gs-gl) tube(or = gr, ir = casing_ir, h = gl, center = false);
-            color(bearing_colour) translate_z(offset+gs) tube(or = or, ir = casing_ir, h = offset, center = false);
+            color(bearing_colour)                           cut_tube(or = or, ir = casing_ir, h = offset, center = false);
+            color(groove_colour)  translate_z(offset)       cut_tube(or = gr, ir = casing_ir, h = gl,center = false);
+            color(bearing_colour) translate_z(offset+gl)    cut_tube(or = or, ir = casing_ir, h = gs-2*gl, center = false);
+            color(groove_colour)  translate_z(offset+gs-gl) cut_tube(or = gr, ir = casing_ir, h = gl, center = false);
+            color(bearing_colour) translate_z(offset+gs)    cut_tube(or = or, ir = casing_ir, h = offset, center = false);
         }
     }
     rod_r =  bearing_rod_dia(type) / 2;
     color(seal_colour)
-        tube(or = casing_ir, ir = rod_r + eps, h = length - 0.5);
+        cut_tube(or = casing_ir, ir = rod_r + eps, h = length - 0.5);
 
     color(seal_colour * 0.8)
-        tube(or = rod_r * 1.12, ir = rod_r, h = length);
+        cut_tube(or = rod_r * 1.12, ir = rod_r, h = length);
 }

vitamins/linear_bearings.scad

@@ -20,25 +20,27 @@
 //
 // Linear bearings
 //
-//                     L  od  id   gl    gd    gs
-LM16UU  = ["LM16UU",  37, 28, 16, 1.6, 27.0, 26.5];
-LM16LUU = ["LM16LUU", 70, 28, 16, 1.6, 27.0, 53.0];
-LM12UU  = ["LM12UU",  30, 21, 12, 1.3, 20.0, 23.0];
-LM12LUU = ["LM12LUU", 57, 21, 12, 1.3, 20.0, 46.0];
-LM10UU  = ["LM10UU",  29, 19, 10, 1.3, 18.0, 22.0];
-LM10LUU = ["LM10LUU", 55, 19, 10, 1.3, 18.0, 44.0];
-LM8UU   = ["LM8UU",   24, 15,  8, 1.1, 14.3, 17.5];
-LM8LUU  = ["LM8LUU",  45, 15,  8, 1.1, 14.3, 35.0];
-LM6UU   = ["LM6UU",   19, 12,  6, 1.1, 11.5, 13.5];
-LM6LUU  = ["LM6LUU",  35, 12,  6, 1.1, 11.5, 27.0];
-LM5UU   = ["LM5UU",   15, 10,  5, 1.1,  9.5, 10.2];
-LM5LUU  = ["LM5LUU",  28, 10,  5, 1.1,  9.5, 20.4];
-LM4UU   = ["LM4UU",   12,  8,  4,   0,    0,    0];
-LM4LUU  = ["LM4LUU",  23,  8,  4,   0,    0,    0];
-LM3UU   = ["LM3UU",   10,  7,  3,   0,    0,    0];
-LM3LUU  = ["LM3LUU",  19,  7,  3,   0,    0,    0];
+//                      L  od  id   gl    gd    gs   h1
+LM16UU   = ["LM16UU",   37, 28, 16, 1.6, 27.0, 26.5];
+LM16LUU  = ["LM16LUU",  70, 28, 16, 1.6, 27.0, 53.0];
+LM16UUOP = ["LM16UUOP", 37, 28, 16, 1.6, 27.0, 26.5, 11];
+LM12UU   = ["LM12UU",   30, 21, 12, 1.3, 20.0, 23.0];
+LM12LUU  = ["LM12LUU",  57, 21, 12, 1.3, 20.0, 46.0];
+LM10UU   = ["LM10UU",   29, 19, 10, 1.3, 18.0, 22.0];
+LM10LUU  = ["LM10LUU",  55, 19, 10, 1.3, 18.0, 44.0];
+LM8UU    = ["LM8UU",    24, 15,  8, 1.1, 14.3, 17.5];
+LM8LUU   = ["LM8LUU",   45, 15,  8, 1.1, 14.3, 35.0];
+LM6UU    = ["LM6UU",    19, 12,  6, 1.1, 11.5, 13.5];
+LM6LUU   = ["LM6LUU",   35, 12,  6, 1.1, 11.5, 27.0];
+LM5UU    = ["LM5UU",    15, 10,  5, 1.1,  9.5, 10.2];
+LM5LUU   = ["LM5LUU",   28, 10,  5, 1.1,  9.5, 20.4];
+LM4UU    = ["LM4UU",    12,  8,  4,   0,    0,    0];
+LM4LUU   = ["LM4LUU",   23,  8,  4,   0,    0,    0];
+LM3UU    = ["LM3UU",    10,  7,  3,   0,    0,    0];
+LM3LUU   = ["LM3LUU",   19,  7,  3,   0,    0,    0];
 
 linear_bearings      = [LM3UU,  LM4UU,  LM5UU,  LM6UU,  LM8UU,  LM10UU,  LM12UU,  LM16UU];
 long_linear_bearings = [LM3LUU, LM4LUU, LM5LUU, LM6LUU, LM8LUU, LM10LUU, LM12LUU, LM16LUU];
+open_linear_bearings = [LM16UUOP];
 
 use <linear_bearing.scad>

vitamins/pcbs.scad

@@ -1040,11 +1040,46 @@ PanelDue_v3 = ["PanelDue_v3", "Panel Due v3.0a LCD Display interface", 53, 73, 1
     ],
    ];
 
+//================================================
+// Adafruit Feather
+// by Chris Lott, chris@thestumbler.io
+// Sacheon South Korea, 17 Jul 2023
+//================================================
+// NOTES:
+// * mounting holes should be accurate
+// * corner radius was just eyeballed
+// * pin headers should be accurate
+// * battery and qwiik connectore just eyeballed
+
+Feather405 = let(size = [inch(2.0), inch(0.9)])
+ ["Feather405", "Adafruit Feather 405",
+  size.x, size.y, 1.6, inch(0.10),
+  inch(0.1), inch(0.175), "green", false,
+          [[ inch(0.1),  inch(0.1) ], // Holes
+          [ -inch(0.1),  inch(0.1) ],
+          [ -inch(0.1), -inch(0.1) ],
+          [  inch(0.1), -inch(0.1) ],
+        ],
+  [
+    [size.x / 2, inch(0.05),   0, "-2p54header", 16, 1],
+    [inch(1.2), -inch(0.05),   0, "-2p54header", 12, 1],
+    [inch(1.3),  size.y / 2, -90, "smd_qfp", QFP50P1200X1200X160_64N, "STM32F405"],
+    [ 3,         size.y / 2, 180, "usb_C"],
+    [ 10,        -6.5,       180, "jst_ph", 2, true, grey(25) ],
+    [ -5, 0.40 * size.y,      90, "jst_zh", 4, true, grey(30) ],
+  ], // components
+  [], // accessories
+   [inch(0.65), inch(0.05), 12, 2, gold, inch(0.1), inch(0.8),
+    inch(0.25), inch(0.05), 4,  1, gold, inch(0.1), 0 ], //  grids of holes for the pins
+  [], // polygon
+  M2p5_dome_screw,
+];
+
 tiny_pcbs = [XIAO, MP1584EN, TP4056, ESP_01, LIPO_fuel_gauge];
 
 big_pcbs = [BTT_RELAY_V1_2, BTT_SKR_MINI_E3_V2_0, BTT_SKR_E3_TURBO, BTT_SKR_V1_4_TURBO, DuetE, Duex5];
 
-pcbs = [RAMPSEndstop, MT3608, KY_040, L9110S, ZC_A0591, ArduinoNano, RPI_Pico, ESP32_DOIT_V1, RPI0, EnviroPlus, ArduinoUno3, ArduinoLeonardo, WD2002SJ, OPZ2, PanelDue_v3, RPI3A, RPI3, RPI4];
+pcbs = [RAMPSEndstop, MT3608, KY_040, L9110S, ZC_A0591, ArduinoNano, Feather405, RPI_Pico, ESP32_DOIT_V1, RPI0, EnviroPlus, ArduinoUno3, ArduinoLeonardo, WD2002SJ, OPZ2, PanelDue_v3, RPI3A, RPI3, RPI4];
 
 pcbs_not_shown = [Melzi, Duex2, PSU12V1A, Keyes5p1, PI_IO, ExtruderPCB];
 

vitamins/potentiometer.scad

@@ -32,7 +32,7 @@ function pot_face(type)     = type[2];  //! Faceplate rib width, plate depth and
 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_p(type) = type[6];  //! Thread pitch
 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

vitamins/sbr_rail.scad

@@ -0,0 +1,123 @@
+//
+// NopSCADlib Copyright Chris Palmer 2023
+// 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/>.
+//
+
+//
+//! SBR rails
+//!
+//! The rails are drawn from the center of the rod.
+//! `sbr_rail_center_height(type)` can be used to determine where the bottom of the rail is.
+//
+include <../utils/core/core.scad>
+use <bearing_block.scad>
+use <linear_bearing.scad>
+use <rod.scad>
+use <screw.scad>
+
+function sbr_rail_diameter(type)        = type[1]; //! Diameter of the rod
+function sbr_rail_center_height(type)   = type[2]; //! Height of the center above the bottom of the rail
+function sbr_rail_base_width(type)      = type[3]; //! Width of the rail base
+function sbr_rail_carriage(type)        = type[5]; //! Carriage to use with this rail
+function sbr_rail_screw(type)           = type[7]; //! Screw to fasten this rail
+
+module sbr_rail(type , l) { //! Draw an SBR rail
+    base_colour = grey(70);
+    screw_colour = grey(10);
+    d = sbr_rail_diameter(type);
+    h = sbr_rail_center_height(type);
+    B = sbr_rail_base_width(type);
+    T = type[4];
+    C = type[8];
+    S2 = sbr_rail_screw(type);
+
+    S3 = type[9];   // Screw that fastens the rod to the base
+    S3L = type[10]; // length of that screw
+
+    h1 = open_bearing_width(sbr_bearing(sbr_rail_carriage(type)));
+
+    vitamin(str("sbr_rail(", d, ", ", l, "): SBR", d, " rail, length ", l, "mm"));
+
+    not_on_bom()
+        no_explode()
+            rod(d, l, center=true);
+
+    base = (h1/2 + C/2) /2;  // guess, not clear from drawings
+
+    color(base_colour)
+        difference() {
+            linear_extrude(l - 5, center=true, convexity=2)
+                translate([0,h-(T/2),0])
+                    polygon([
+                        [-h1/2, -T/2],
+                        [-h1/2 - T/2, T/2],
+                        [-B/2, T/2],
+                        [-B/2, -T/2],
+                        [-base, -T/2],
+                        [-d/4, -h+(d/2)],
+                        [d/4, -h+(d/2)],
+                        [base, -T/2],
+                        [B/2, -T/2],
+                        [B/2, T/2],
+                        [h1/2 + T/2, T/2],
+                        [h1/2, -T/2],
+                    ]);
+            sbr_screw_locations(type, l)
+                translate([0,h-T+0.01,0])
+                    rotate([90,0,0])
+                        cylinder(r=screw_clearance_radius(S3), h=S3L, center=true);
+            sbr_screw_positions(type, l)
+                translate([0,T/2,0])
+                    rotate([90,0,0])
+                        cylinder(r=screw_clearance_radius(S2), h=T+0.1, center=true);
+
+        }
+
+    not_on_bom()
+        no_explode()
+            color(screw_colour)
+                sbr_screw_locations(type, l)
+                    translate([0,h-T,0])
+                        rotate([270,0,0])
+                            screw(S3, S3L);
+}
+
+module sbr_screw_locations(type, l) { //! Linear locations of screws
+    P = type[6];
+
+    count = floor(l / P);
+    first = (l - count * P)/2;
+    N = first == 0 ? P/2 : first;  // we don't want screws right on the edge
+
+    for (x = [N:P:l])
+        translate([0,0,l/2 - x])
+            children();
+}
+
+module sbr_screw_positions(type, l) { //! Screw positions
+    h = type[2];
+    T = type[4];
+    C = type[8];
+    S2 = sbr_rail_screw(type);
+
+    for (x = [-C/2, C/2])
+        translate([x,h-T, 0])
+            sbr_screw_locations(type, l)
+                children();
+
+
+}

vitamins/sbr_rails.scad

@@ -0,0 +1,31 @@
+//
+// NopSCADlib Copyright Chris Palmer 2023
+// 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/bearing_blocks.scad>
+
+//
+// SBR Rails
+//
+
+//                        d  h   B   T  carriage P    S2            C   S3            S3L
+SBR16S     = ["SBR16S",  16, 25, 40, 5, SBR16UU, 150, M5_cap_screw, 30, M5_cap_screw, 18  ];
+
+sbr_rails = [SBR16S];
+
+use <sbr_rail.scad>

vitamins/screw.scad

@@ -41,7 +41,7 @@ function screw_washer(type)           = type[9];     //! Default washer
 function screw_nut(type)              = type[10];    //! Default nut
 function screw_pilot_hole(type)       = type[11];    //! Pilot hole radius for wood screws, tap radius for machine screws
 function screw_clearance_radius(type) = type[12];    //! Clearance hole radius
-function screw_thread_diameter(type)  = type[13];    //! Thread diameter, if different from nominal diamter
+function screw_thread_diameter(type)  = type[13];    //! Thread diameter, if different from nominal diameter
 function screw_nut_radius(type) = screw_nut(type) ? nut_radius(screw_nut(type)) : 0; //! Radius of matching nut
 function screw_boss_diameter(type) = max(washer_diameter(screw_washer(type)) + 1, 2 * (screw_nut_radius(type) + 3 * extrusion_width)); //! Boss big enough for nut trap and washer
 function screw_head_depth(type, d = 0) =             //! How far a counter sink head will go into a straight hole diameter d