Drive gear improvements.

drive_gear_parts.scad

@@ -5,37 +5,56 @@ use <publicDomainGearV1.1.scad>
 
 module drive_gear() {
 	h = 10;
+	shaft = 5.2;
 	render(convexity=10) union() {
 		difference() {
+			// Herringbone gear
 			mirror_copy([0, 0, 1]) {
 				translate([0, 0, h/4]) {
 					gear (
 						mm_per_tooth    = 5,
 						number_of_teeth = 9,
 						thickness       = h/2,
-						hole_diameter   = 5.2,
+						hole_diameter   = shaft,
 						twist           = 15,
 						teeth_to_hide   = 0,
 						pressure_angle  = 20
 					);
 				}
 			}
+
+			// Bevel end of gear.
 			tube(h=6, r1=20, r2=7.5, wall=4);
 		}
 		difference() {
 			union() {
+				// Fix up gear weirdness with solid center.
 				cylinder(h=h, r=5.5, center=true);
-				translate([0, 0, -(h+7)/2])
+
-					cylinder(h=7, r=9, center=true);
+				// Base
+				translate([0, 0, -(h+11)/2])
+					cylinder(h=11, r=9, center=true);
 			}
-			cylinder(h=(h+5)*3, r=5.2/2, center=true, $fn=16);
+
-			translate([5/2+1, 0, -(h/2+12)/2]) {
+			difference() {
+				// Shaft hole
+				cylinder(h=(h+5)*3, r=shaft/2, center=true, $fn=16);
+
+				// Shaft flat side.
+				translate([1.4*shaft, 0, 0])
+					cube(size=[shaft*2, shaft*2, (h+6)*3], center=true);
+			}
+
+			translate([5/2+1, 0, -(h/2+5+11)/2]) {
 				yrot(90) {
+					// Nut Slot
 					scale([1.1, 1.1, 1.1]) hull() {
 						metric_nut(size=3, hole=false);
 						translate([5, 0, 0])
 							metric_nut(size=3, hole=false);
 					}
+
+					// Set screw hole.
 					translate([0, 0, 2])
 						cylinder(r=3.2/2, h=9, center=true, $fn=8);
 				}