8. grip ball better with taller wall

diff --git a/3d-printables/caster-standoff.scad b/3d-printables/caster-standoff.scad
index 39ab746242d86e49c82a429f4d01c44c481c0610..27288faf94debd74c3d8cd68093cf8fd609a17d0 100644 (file)
--- a/3d-printables/caster-standoff.scad
+++ b/3d-printables/caster-standoff.scad
@@ -7,7 +7,17 @@
 // use 10 ish for development, 60 or so for printing
 $fn = 60;
 
-standoff_radius = 14.732 / 2; // 0.580 / 2 inches from spec sheet
+/* measured with calipers */
+ball_diameter = 12.7 + 1.25;
+ball_radius = ball_diameter / 2;
+
+wall_thickness = 1;
+holder_height = (25 / 32) * ball_diameter + wall_thickness;
+
+holder_radius = ball_radius + wall_thickness;
+holder_diameter = holder_radius * 2;
+
+standoff_radius = holder_radius; // 0.580 / 2 inches from spec sheet
 standoff_height = 48; // eyeballed
 
 // eyeballed caster flange height, (0.580/5) inches, times 2 to be stronger
@@ -45,14 +55,13 @@ module deck_flange_reinforcement(){
                 deck_flange_radius]);}}}}}
 
 module ball_holder(){
+  gap = wall_thickness * 4;
   difference (){
     cylinder(r = holder_radius, h = holder_height);
     translate([0, 0, ball_radius + wall_thickness]){
       sphere(r = ball_radius);}
     translate([0, 0, holder_height / 2 + wall_thickness]){
-      cube([holder_diameter + 0.1,
-            wall_thickness * 2,
-            holder_height],
+      cube([holder_diameter + 0.1, gap, holder_height],
            center = true);}}}
 
 module caster_standoff(){