So far it's been working better then I thought it would.
The plans I found on the internet, sorry no link, but there is lots of them available.
The 3 Idler pulleys are actually 2 1/2" skateboard wheels, mounted on 5/16 bolts.
The main drive pulley, came from Original Blade Maker in Oregon. Since I had a slow speed motor, (1750rpm) it needed a 5" drive pulley.
My motor is a little under powered, its a 3/4 hp I had kicking around, I recommend at least a 1hp, bigger if you wanted.