From 58c7cfade8949aefdf4cce5e30f8139deb0cf8df Mon Sep 17 00:00:00 2001
From: Nicolas MASSE <nicolas.masse@itix.fr>
Date: Thu, 15 Mar 2018 15:02:55 +0100
Subject: [PATCH] children

---
 010-Children/ball-bearing.scad | 46 ++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 010-Children/ball-bearing.scad

diff --git a/010-Children/ball-bearing.scad b/010-Children/ball-bearing.scad
new file mode 100644
index 0000000..83da572
--- /dev/null
+++ b/010-Children/ball-bearing.scad
@@ -0,0 +1,46 @@
+$fa=1;
+$fs=0.5;
+$fn = 50;
+
+// Place balls inside the bearing groove based on a sample ball provided as
+// children
+module place_evenly(n) {
+  step = 360 / n;
+  for(t=[0:step:369]) {
+    rotate([0,0,t])
+      children();
+  }
+}
+
+module ball_bearing(od, id, bd, width, groove, space) {
+  center_line_radius = (od-id)/4+id/2;
+
+  difference() {
+    union() {
+      // outer ring
+      difference() {
+        cylinder(d=od, h=width, center=true);
+        cylinder(d=id+bd*(1-groove)*2, h=width+1, center=true);
+      }
+      // inner ring
+      difference() {
+        cylinder(d=od-bd*(1-groove)*2, h=width, center=true);
+        cylinder(d=id, h=width+1, center=true);
+      }
+    }
+
+    // groove
+    rotate_extrude(convexity = 10) {
+      translate([center_line_radius, 0, 0]) circle(d=bd);
+    }
+  }
+
+  // Place balls inside the groove
+  n = floor(center_line_radius * 2 * PI / (bd * (1+space)));
+  place_evenly(n) {
+    translate([center_line_radius, 0, 0]) sphere(d=bd);
+  }
+}
+
+// 6017 SKF Metric Open Deep Groove Ball Bearing 85x130x22mm
+ball_bearing(130, 85, 19, 22, 0.15, 0.5);