Have a 5hp motor with the front shaft worn where the bearing sits. Has been chattering for long enough to wear from 40mm down to ~39.6 in places. I've welded a less valuable one and turned it down in the lathe but remember it not being easy. Aside from that, I can't remember how I approached it! Any tips? I guess I'll have to do opposing runs cooling the shaft between goes.... Alternatively, seeing as it looks like it'll need to be lathed either way, I could turn the 38mm pulley shaft the next size down and machine a sleeve for the bearing to sit on or get an undersize bearing if one exists. Think I'd like to keep that as a plan B though as my machining is not all that hot.