Repairing an outboard boat motor with 3D printing

Recently, my father in law came to me with an interesting problem. The pull-starter gear on his auction-purchased outboard motor had been stripped out pretty badly (he thinks somebody pulled the cord while it was running).

Step 1 was to start with some simple measurements, and SCAD:
[php]
$fn = 60;

difference() {
union() {
cylinder(r = 22.22, h = 2.30);
cylinder(r = 15.00, h = 11.10);

for(r = [0: 25.71: 360]) {
rotate([0, 0, r])
hull() {
translate([19.50, 0, 0])
cylinder(r = 1, h = 11.00);

translate([16.00, 0, 0])
cylinder(r = 2.1, h = 11.00);

translate([0, 0, 0])
cylinder(r = 5.00, h = 11.00);
}
}
}

translate([0, 0, -0.05])
cylinder(h = 11.20, r = 7.50);
}
[/php]
gives us:
.

From here, we can plate a few up (in case one isn’t up to snuff, he’ll have extras), and print them out in solid ABS. Shown below is the finished plate (still on the printer) with the original gear next to it for comparison.

And here it is installed:  (it’s taken a bit of a beating, that’s why I printed 4 though!)