From 3c9a59dcac7b940a4f8f9dcee55ac74116c87d3c Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 20 Nov 2021 13:20:57 +0000
Subject: [PATCH] nutbox: transfer from other tree

from a4d84a2286021d5a47c93edff24f2f0d5a863f19

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 .gitignore     |  1 +
 Makefile       |  2 +-
 nutbox.scad.m4 | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 nutbox.scad.m4

diff --git a/.gitignore b/.gitignore
index 636889f..f328663 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ light-bracket.stl
 *.tmp
 *.fig.bak
 funcs.scad
+nutbox.scad
 powerbank-anker-10000.dxf*
 knifeblock-knives-*.dxf*
 pandemic-counter-l*.dxf
diff --git a/Makefile b/Makefile
index 94cf025..35bfad0 100644
--- a/Makefile
+++ b/Makefile
@@ -24,7 +24,7 @@ QUACKS_SCADS = $(addsuffix .scad, $(QUACKSES))
 
 USING_AUTOS ?= $(FILAMENTSPOOL_AUTOS) xeno-drivebay-bracket dungeonquest-cone anke-gps-bracket cable-hole-trunking-cover anglepoise-neck crossbar-computer-led-mount wardrobe-hook knifeblock pandemic-counter pattress-boxes-3-cover bike-lipo-box earring-stand bike-stalk-led-mount sewing-table sewing-table-test sewing-table-jig maglite-holder poster-tube-lid poster-tube-lid-coarse fairphone-case fairphone-battery-case lock-inframe-bracket ksafe-base $(QUACKSES) quacks-ingredients-demos mic-table-clamp nook-case nook-case-test scaffold-clamp-common.scad scaffold-clamp-tensioner scaffold-clamp-straphook powerbank-bike-clamp
 
-AUTO_INCS += sealing-box.scad sewing-table.scad \
+AUTO_INCS += sealing-box.scad sewing-table.scad nutbox.scad \
 	     powerbank-anker-10000.dxf \
 	     poster-tube-lid-parametric.scad $(QUACKS_SCADS)
 
diff --git a/nutbox.scad.m4 b/nutbox.scad.m4
new file mode 100644
index 0000000..5384eff
--- /dev/null
+++ b/nutbox.scad.m4
@@ -0,0 +1,65 @@
+// -*- C -*-
+// edit nutbos.scad.m4, not nutbos.scad!
+// shaft, nut_across, nut_thick, nut_recess, wall, ceil
+
+nutbox_data_M4 = [
+		   4.0 + 0.5,
+		   6.89 + 0.45,
+		   3.10 + 0.75,
+		   0.75,
+		   2.0,
+		   2.5
+		   ];
+
+nutbox_data_M3 = [
+		   3.0 + 0.5,
+		   5.48 + 0.45,
+		   2.26 + 0.75,
+		   0.75,
+		   1.8,
+		   2.0
+		   ];
+
+m4_define(shaft,      (nutbox_data[0]))
+m4_define(nut_across, (nutbox_data[1]))
+m4_define(nut_thick,  (nutbox_data[2]))
+m4_define(nut_recess, (nutbox_data[3]))
+m4_define(wall,       (nutbox_data[4]))
+m4_define(ceil,       (nutbox_data[5]))
+
+m4_define(nut_dia, (nut_across / cos(30)))
+m4_define(outer_size, (nut_dia + wall * 2))
+m4_define(h_base, (ceil + nut_thick + nut_recess))
+
+function NutBox_shaft(nutbox_data) = shaft;
+function NutBox_outer_size(nutbox_data) = outer_size;
+function NutBox_h_base(nutbox_data) = h_base;
+function NutBox_wall(nutbox_data) = wall; // not sure why anyone needs this
+
+module NutBox(nutbox_data, h, h_above_extra=0) {
+  // origin is centre of top of mount
+  // entrance is to positive y
+  // height is h which must be at least h_base
+  // can be mad extra tall (with hole all the way through) with h_above_extra
+  w = outer_size;
+  difference(){
+    mirror([0,0,1]) translate([-w/2,-w/2, -h_above_extra])
+      cube([w,w, h + h_above_extra]);
+    mirror([0,0,1]) translate([0,0,-1 -h_above_extra])
+      cylinder(r = shaft/2, h = h+2 + h_above_extra, $fn=20);
+    for (offset = [ [0,0, -nut_recess],
+		    [0, outer_size, 0] ]) {
+      hull(){
+	for (toffset = [[0,0,0], offset]) {
+	  translate(toffset)
+	    translate([0,0, -ceil])
+	    mirror([0,0,1])
+	    rotate([0,0, 360/6/2])
+	    cylinder(r = nut_dia/2,
+		     h = nut_thick,
+		     $fn = 6);
+	}
+      }
+    }
+  }
+}
-- 
2.30.2