Instead of spending $50+ on a wheel dishing tool, I decided to design my own. The parts of this tool are designed to work with what I had laying around; Thule square crossbar, a ½" carriage bolt, and M6 knobs.
To build exactly I as I did, you will need about 1 meter of Thule square crossbar, a ½" carriage bolt 8" long, two ½-13 nuts, two M6 nuts, two M6 bolts x 20mm (dependent on your knob size), and whatever M6 knobs you have.
You'll need to drill a ½" hole in the center of the Thule bar (large side)
There are two styles of the “side arms”, one with a curved end and other flat. The tool will sit better using the flat arms. There are also two different center ends. One flat w/ lip, and one with a “spike” to semi-self-center on hub
The author marked this model as their own original creation.