Originally Posted by 2_many_hobbies  Ok found some info on how to install AC bearings here
Does anybody use this heated method and then crushing the inner races together for preload or is my method above of the inner spacer that would provide an adjustable preload preferred for home built spindles?? |
It is important for both the inner and outer races to be a very snug fit. This can be accomplished by either making the shaft very slightly oversize, and the outer race recess slightly undersize, so both are a light press fit, then press them into place. Or, heat the bearing so it drops onto the shaft, and heat the outer race support so it also drops onto the bearing. Either approach will work just fine. Unless you're using ground pre-loaded matched bearings (think $$$$$), then you should use shims to set the pre-load. Without adequate pre-load, you WILL get end float. I would not recommend making the preload adjustable by the shaft nut, as it will be very difficult to get it set right. Too loose, and you have end float (which leads to backlash). Too tight, and the bearing life will be compromised. The only question is how much preload is "enough". Without any hard data, I would suggest shimming such that you are at the point where the slightest additional pre-load noticeably increases torque requirement. Since it can be hard to come up with very thin (less than 0.001") shims, you might find it easier to space the bearings apart, and use machined shims (hollow tubes) that you custom machine to the required length. This is how the spindle bearings in many large mills are setup.
Regards,
Ray L.