Hi guys/gals, I'm thinking of building a 2x72 grinder using only 2 wheels - a drive wheel and a driven/tracking wheel. I also want to mount a disc on one of the wheels for a disc sander. I would mount a platen behind the belt between the wheels. I'm thinking of using a 10” serrated contact drive wheel which would also allow for a hollow grind. I've got a 4.5hp, 2 speed motor salvaged from a old hot tub pump. I would also use a step pulley system to give further speed control. Anybody tried this type of setup? Why are most people using the more traditional 4 wheel setups?