From f75641f364d085501e04f29e34ef8cb1620aadff Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Sun, 6 Jul 2014 06:41:16 +0000
Subject: [PATCH] ball end

---
 ball-end.scad | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 ball-end.scad

diff --git a/ball-end.scad b/ball-end.scad
new file mode 100644
index 0000000..f316f9c
--- /dev/null
+++ b/ball-end.scad
@@ -0,0 +1,33 @@
+$fn=40;
+HOLE_RADIUS=2.4; // my Wanhao Duplicator 4 makes no errors with Slic3r, 2.4mm is ideal lego hole
+
+difference() {
+  union() {
+    translate([0, 0, 16+4]) sphere(r=3);
+    hull() {
+      translate([0, 0, 4]) cylinder(r=4, h=4+8);
+      translate([0, 0, 4]) cylinder(r=1.5, h=4+8+3);
+    }
+    translate([0, 4, 4]) rotate([90, 0, 0]) cylinder(r=4, h=8);
+  }
+  translate([0, 4.1, 4-0.1]) rotate([90, 0, 0]) linear_extrude(height=8.2) axle();
+}
+
+module axle() {
+  axle_gap = 1.95;
+  union() {
+    translate([-HOLE_RADIUS, -axle_gap/2, 0])
+      roundedRect(HOLE_RADIUS * 2, axle_gap, .2);
+    translate([-axle_gap/2, -HOLE_RADIUS, 0])
+      roundedRect(axle_gap, HOLE_RADIUS * 2, .2);
+  }
+}
+
+module roundedRect(x, y, radius) {
+  hull() {
+    translate([radius, radius, 0]) circle(r=radius);
+    translate([x - radius, radius, 0]) circle(r=radius);
+    translate([x - radius, y - radius, 0]) circle(r=radius);
+    translate([radius, y - radius, 0]) circle(r=radius);
+  }
+}