About thirty years ago I one on a job that was very old then, the type where the bowl...
turns and locks into the base. That part was worn and pretty sloppy. When in started up, made a sound sort of like when an old car was trying to start errrrr and then rrrrrrr and then it would start. Used that thing for another five years, many, many batches of cookies and loaves of bread and more.
Finally the bowl would not stay in place and it was making some other interesting noises, so retired it.
Have a 6qt. at home now, black. Got a good price from Chef's catalog long before I had internet, free shiping.
First one died the second time I used it--they paid posatge back and sent me another that's been fine so far.