Boat Engine Alignment Tool

This is a tool to align the prop shaft flange and transmission flange on a boat. It has 3 parts. The handle accepts a 3/8 x 4" bolt and has a knob to tighten/loosen it. The shim holder is designed to accept a single edge razor blade (make sure to dull it on a wet stone). The captured nut has a lip that catches the edge of the flange, so it doesn't spin. The captured nut works better if you run a 3/8" tap through it, as I haven't perfected 3D printing screw threads. The hole in the shim holder is to store the 3 parts together when it is not being used.

The tool allows you to take the measurements required to align the flanges without using C-clamps, spring clamps, or other wrenches. The shim holder gives a more repeatable shim insert than sticking a loose shim in and provides more accurate measurements. The razor blade I used was 0.0115" thick. so when you tighten it down, you can insert a 0.011" shim easily and 0.011" is your reference thickness.

The two pictures show the components