home made bump steer gauge,

I'm designing some billet steering arms and I want to get my bump steer prefect now that I have the opportunity. I was looking at some bump steer gauges particularly the intercomp digital model that starts at like $500.

After watching this video, I was surprised at how simple of a system it is for it's price,

http://www.youtube.com/watch?v=Stp9kHAGfXQ


The system they have actually looks a little complex for the purpose it serves. I've got a dial indicator and some aluminum. All I need to do is rig up a little frame for the dial indicator, punch a 4.75x5 bolt pattern and hub hole,  then I can model my bumpsteer and adjust accordingly.
Am I missing something here? This almost seems to easy.

You will want a dial indicator at the front too instead of the bearing. The worst part about using dial indicators instead of digital is watching the gauges spin two different ways. I nearly lost my mind the first couple of times