Re: Questions on bearings for Belt Drive Conversion
I made the belt drive you have.
You have spindle bearings and the belt drive has bearings. The drawing you show is of the belt drive but your talking about the spindle bearings.
I don't have all the bearing # in hand but all the RF-45 clones have tapered roller bearings in the spindle. All are China bearings but if they are not full of rust should be OK to about 5000 RPM if you re pack them with a good grease and set the preload slightly low. Standard grease is a bit too thin and will melt out. I would have to look up the proper grease #.
Most the belt drives I made have a higher top speed with a VFD motor at 100 hz. Generly 6.5K with a 1750 RPM motor. If you plan on running over lets say 4K all the time then its a good idea to change to A\C bearings.
Its not really all that easy to change them and get the preload set correctly. You set the preload with the two spanner nuts at the top. The problem is the top bearing generally will not slide easily on the shaft so will stick slip as you set the preload. This makes using a soft blow hammer useful in setting the preload just right. Any made in Japan A\C standard grade bearing is just fine. I got about .0003" of runout from one.
youtube videos of the G0704 under the name arizonavideo99