I bought a grill rotisserie motor from the hardware store (Lowe's) and attached it to a stand and just stick it in the rear axle with a rubber bushing on it to roll two tires at a time. I know that's not ideal, but it's the cheapest and easiest way to get started in the tire rolling program. Improvisation.
I would post pics of mine but cant figure out how! Lol. Go to lowes and buy the cheap rotisserie motor for a grill. I took bearings from skateboard wheels and put them inside a piece of 5/8 emt conduit for the rollers. And used a heat gun for the heat source. I took a piece of 2 inch conduit, and drilled holes along the length to distribute the heat evenly.