Dave,

Since you and I are both in CT, we have the new emissions laws....sooooo, here's a thought:

Instead of building something with a 5hp, use the cars motor...on one of those roller units at a DMV inspection station. Granted, you could probably build a similar set up (cost ~$200 in steel material) in a MUCH scaled down fashion.

Again, it is Friday, and I am showing negative productivity numbers today at the office.

Regards,
Alan