dobervich: make caster standoff smaller for faster printing

[challenge-bot] / caster-standoff.scad

diff --git a/caster-standoff.scad b/caster-standoff.scad
index f61ac3aa90d27f62a4dd8e84e3ca3543971c87ed..973aa00b32980c2b88811c48df19b54333551d7c 100644 (file)
--- a/caster-standoff.scad
+++ b/caster-standoff.scad
@@ -4,31 +4,92 @@
 // https://gitorious.org/ozzloy/challenge-bot
 // https://github.com/waynegramlich/challenge-bot
 
-$fn = 100;
-
-module ball_screws(){
-  between = 14.732;  // 0.580 inches
-  screw_radius = 2.286/2;  // 0.090 inches
-  screw_length = 15;  // i made this up
-  translate([between/2, 0, 0]) cylinder(h = screw_length, r = screw_radius);
-  translate([-between/2, 0, 0]) cylinder(h = screw_length, r = screw_radius);}
-
-module fixture(){
-  height = 2.9464;
-  width = 20.32;
-  between = 14.732;
-  side_radius = (width - between)/2;
-  translate([between/2, 0, 0]) cylinder(h = height, r = side_radius);
-  translate([-between/2, 0, 0]) cylinder(h = height, r = side_radius);
-  }
+standoff_radius = 14.732 / 2; // 0.580 / 2 inches from spec sheet
+standoff_height = 55; // eyeballed
+
+nut_short_side = 4.7; // from calipers
+nut_height = 1.6; // from calipers
+
+// eyeballed caster flange height, (0.580/5) inches, times 2 to be stronger
+caster_flange_height = 2.9464 * 2;
+caster_flange_width = 20.32;  // 0.800 inches
+caster_flange_screw_radius = 2.286 / 2;  // 0.090 inches
+caster_flange_screw_length = 8; // eyeballed
+
+deck_grid_width = 17.4; // guessing
+deck_flange_height = 2.9464 * 2;
+deck_flange_screw_radius = 3.556 / 2;  // For #6 machine screws
+deck_flange_radius = deck_grid_width * 1.5;
+
+module deck_flange(){
+  difference(){
+    cylinder(h = deck_flange_height, r = deck_flange_radius);
+    for(ii = [-1, 1]){
+      translate([deck_grid_width * ii, 0, -.1])
+        cylinder(h = deck_flange_height * 1.1,
+                 r = deck_flange_screw_radius,
+                 $fn = 20);}
+    for(ii = [-1, 1]){
+      translate([0, deck_grid_width * ii, -.1])
+        cylinder(h = deck_flange_height * 1.1,
+                 r = deck_flange_screw_radius,
+                 $fn = 20);}}}
+
+module deck_flange_reinforcement(){
+  translate([-deck_flange_radius,
+             -.5 * deck_flange_height,
+             deck_flange_height]){
+    difference (){
+      cube([deck_flange_radius, deck_flange_height, deck_flange_radius]);
+      translate([-.1, -.05 * deck_flange_height, 0]){
+        rotate([0, -45, 0]){
+          cube([deck_flange_radius * 1.5, // 1.5 is bigger than sqrt(2)
+                deck_flange_height * 1.1, // 1.1 is bigger than 1
+                deck_flange_radius]);}}}}}
+
+module caster_flange_screws(){
+  translate([standoff_radius, 0, 0])
+    cylinder(h = caster_flange_screw_length,
+             r = caster_flange_screw_radius,
+             $fn = 20);
+  translate([-standoff_radius, 0, 0])
+    cylinder(h = caster_flange_screw_length,
+             r = caster_flange_screw_radius,
+             $fn = 20);}
+
+module caster_flange(){
+  side_radius = caster_flange_width / 2 - standoff_radius;
+  hull(){
+    cylinder(h = caster_flange_height, r = standoff_radius);
+    translate([standoff_radius, 0, 0])
+      cylinder(h = caster_flange_height, r = side_radius);
+    translate([-standoff_radius, 0, 0])
+      cylinder(h = caster_flange_height, r = side_radius);}}
+
+module nut(size, height){
+    width = size/1.75;
+    for (r = [-60, 0, 60]) rotate([0,0,r]) cube([width, size, height], true);}
+
+module nuts(){
+  translate([standoff_radius, 0, nut_height/2])
+    nut(nut_short_side, nut_height);
+  translate([-standoff_radius, 0, nut_height/2])
+    nut(nut_short_side, nut_height);}
 
 module caster_standoff(){
-  height = 43;
-  caster_radius = 14.732/2;
   difference(){
     union(){
-      cylinder(h = height, r = caster_radius);
-      fixture();}
-    scale([1, 1, 1.1]) translate([0, 0, -.1]) ball_screws();}}
+      cylinder(h = standoff_height, r = standoff_radius);
+      translate([0, 0, standoff_height - caster_flange_height])
+        caster_flange();}
+    translate([0, 0, standoff_height - caster_flange_screw_length * 1.1 + 0.1])
+      scale([1, 1, 1.1])
+        caster_flange_screws();
+    translate([0, 0, standoff_height - (caster_flange_height + nut_height)])
+      nuts();}
+  deck_flange();
+  for(ii = [0:3]){
+    rotate([0, 0, 45 + 90 * ii])
+      deck_flange_reinforcement();}}
 
 caster_standoff();