My question is this: What size should I drill/ream/bore the hole in the disc roller? The bronze bearings I've purchased are 3/4" OD and 1/2" ID. I've already drilled 1/2" holes in the frame for the pins and the bushings slide over them quite nice. However, I need to press in the bushings so they are tight in the disc rollers and don't spin. I've measured the bushings and they are pretty much spot on (0.7500 OD and 0.500 ID). I'm guessing I need to bore the holes slightly under and press in the bushing, but I'm not sure by how much. I guess I could bore a few test holes and figure it out, but thought you guys might help me get it right the first time.