X-Git-Url: http://challenge-bot.com/repos/?a=blobdiff_plain;f=wheel.scad;h=87ec2865c38c456da267159bce0b19b41291c92d;hb=1d64184f60ba90676a4608319d4e17b967cd2f8c;hp=aa3d2686ddca632ccd461197b6df8f1cd28708de;hpb=bc02cd240d188c85cc1333510e63b2a2ff516bc7;p=challenge-bot

diff --git a/wheel.scad b/wheel.scad
index aa3d268..87ec286 100644
--- a/wheel.scad
+++ b/wheel.scad
@@ -4,27 +4,70 @@
 // https://gitorious.org/ozzloy/challenge-bot
 // https://github.com/waynegramlich/challenge-bot
 
+// use $fn = 20 while developing, 100 when about to print
+//  20 will make previews fast
+//  100 will make printing smooth
+$fn = 20;
+
+wheel_depth = 6;
+wheel_radius = 68/2;
+
 module encoder_shaft(){
-  motor_shaft_big = 7/2;
-  motor_shaft_small = 4.65;
-  motor_shaft_length = 7.65 / 2;
+  // measured with calipers, checked against the motor shaft
+  motor_shaft_big = 3.7; // radius, gets doubled in cylinder
+  motor_shaft_small = 4.8; // total length of box
+  motor_shaft_length = wheel_depth * 3 / 4;
 
   intersection(){
-    cylinder(h = motor_shaft_length,
-             r = motor_shaft_big,
-             center = true,
-             $fn=100);
+    cylinder(h = motor_shaft_length, r = motor_shaft_big, center = true);
+    // x direction is multiplied by 2 because the radius of the cylinder
+    // goes in both directions.  the extra .1 is for overlap
     cube([motor_shaft_big * 2.1, motor_shaft_small, motor_shaft_length],
          center = true);}}
 
+module mounting_screw(){
+  cylinder(h = wheel_depth * 1.1, r = 1, center = true);}
+
 module wheel(){
-  depth = 7.65;
-  radius = 68/2;
-  difference(){
-    cylinder(h = depth, r = radius, center = true, $fn=100);
-    translate([0, 0, 7.65/4])
-      scale([1, 1, 1.1])
-        encoder_shaft();
-    cylinder(h = depth * 1.1, r = 1, $fn = 100, center = true);}}
-
-translate([0, 0, 7.65/2]) wheel();
+  translate([0, 0, wheel_depth / 2]){
+    difference(){
+      cylinder(h = wheel_depth, r = wheel_radius, center = true);
+      translate([0, 0, wheel_depth / 4]){
+        scale([1, 1, 1.1]){
+          encoder_shaft();}}
+      mounting_screw();
+      for(i = [1 : 5]){
+        rotate(i * 360/5, [0, 0, 1]){
+          translate([0, 0, -0.6 * wheel_depth])
+            between_spokes();}}
+      translate([0, 0, wheel_depth / 4]){
+        difference(){
+          cylinder(h = wheel_depth / 1.2,
+                   r = 0.85 * wheel_radius,
+                   center = true);
+          cylinder(h = wheel_depth / 1.2,
+                   r = 0.23 * wheel_radius,
+                   center = true);}}}}}
+
+module wheel_block(){
+  cube([wheel_radius, wheel_radius, wheel_depth]);}
+
+module pie_slice(){
+  intersection(){
+    translate([0, 0, wheel_depth / 2]){
+      cylinder(h = wheel_depth,
+               r = 0.85 * wheel_radius,
+               center = true);}
+    translate([0, wheel_radius * 0.3, 0]){
+      rotate([0, 0, (360 / 5) / 2]){
+        intersection(){
+          wheel_block();
+          rotate([0, 0, 90 - 360 / 5])
+            wheel_block();}}}}}
+
+module between_spokes(){
+  minkowski(){
+    pie_slice();
+    cylinder(h = wheel_depth / 2, r = 1);}}
+
+wheel();