Michael Tucker <mact@door.net> wrote

.0002 on the press fit for the ball bearings
The aluminum might work it depends on how thick it is and what grade. Go with
steel and you don't have to worry about it.
MSC sells the bellows to protect the screws, but it is pricey.

"Would layers of aluminum foil be ok for the spacers?"
NO. Did it right the first time. No short cuts.
I always thought that bearings were preloaded with springs, but I make bearing
housing for taper roller bearings.

I am not trying to be rude but does your mama know you are playing with
machines.
Michael