Miter Saw Stop Block

Hi,
I want to build a miter saw station stop block system to accurately, quickly and efficiently position a stop block on a miter saw station.

Basically this is a fence on a miter saw with a computer controlled 'stop' that moves back and forth an stops at the user entered distance from the saw blade. I'm thinking the C channel might work to carry the plate/wheel assembly. I think a belt drive would work well. I watched a tutorial from Brainy-Bits and purchased the electronic hardware. ( ). Now I need to concentrate on the fence, stop and drive system. Any help with parts list, suggestions, etc greatly appreciated. One caveat, I'm assuming I need to protect the drive system from the ever present wood dust!

Thanks,
Roger