How will the motors mount on your grinders? This will dictate how you should make the drive wheels. They should be 2 1/4 -2 1/2" wide. With a face mount to 1/4" plate, and another 1/4" gap behind the wheel this will put a centered set screw right at the end of the shaft. This can be avoided by drilling the hole from the face at an angle. Watch northridge tools video on YouTube with the drive wheel being machined. They leave an extra nub on the backside of the wheel to get more contact on the shaft. Ream/bore and do all the facework on the outside of the drives. Broach the key ways. Drill/tap for the set screws. Machine an accurate STEEL dummy shaft. Use the set screw to secure the wheels on the dummy shaft to turn the backside and diameter using light cuts. This will result in a better balanced wheel. The tracking wheels need to be the same width as the drives. This will make setup easier. The easiest way to make the tracking is to drill/bore a precision hole about 3/16 smaller than the o.d. of your bearings. Make a dummy shaft slightly shorter than the width of the wheel minus the width of one bearing. You can then either drill/tap for a set screw down the center of the wheels or use super glue to hold the wheels while you bore bearing pockets and heat to remove. This is much easier, and more acurate than flipping the wheels and realigning. Especially if you only have a three jaw. The same technique can be used on platen wheels, but platen wheels should only be 2" wide.
