Moved all the mechanical stuff into a subdirectory

mechanical/test_prints.scad

@@ -0,0 +1,28 @@
+include <constants.scad>;
+include <parts.scad>;
+
+module bearing_slot() {
+    intersection() {
+        difference() {
+            translate([- frame_size / 2, - frame_size / 2, 1])
+                cube([frame_size, frame_size, 10]);
+            cylinder(d = bushing_od, h = 6);
+            cylinder(d = rail_diam, h = 12);
+        }
+        union() {
+            cylinder(h = 12, d = frame_size);
+            translate([-frame_size/2, 0, 0])
+            cube([frame_size, frame_size, frame_size]);
+        }
+    }
+}
+
+let($fn = 30) {
+    translate([-28, 0, frame_size/2])
+    rotate([0,90,0]) bearing_slot();
+
+    translate([28, 0, frame_size/2])
+        rotate([0,-90,0]) bearing_slot();
+
+    idler_post(10);
+}