Shims from common materials.

One can find many sources for stock 4 thou and up.  Paper, card stock etc.

For thinner I am trying aluminum foil.

• Reynolds Pitmaster is 1.6 thou
• Reynolds Heavy Duty is 1.0 thou
• Regular foil is about .3 thou

That should about cover it

Together the Pitmaster and Heavy Duty run about $10 at my local grocery store, quite a bargain given that you still have the bulk of the foil to use in the kitchen.

I have seen pitmaster online for as much as $18.  Don't go there.

Update:

Made a hole punch on the lathe for punching the centers.   Started with round stock from rebar that was .450.    Drilled a .shallow 404 hole, desired hole size,  and through drilled a bit larger than 1/4" The flaw here is that my punched holes are .450 not .404.    Need to start with a .404 stock and drill a  .350 or so hole to get a .404 hole.  But these are clearance holes in aluminum foil so I don't see a problem.

It needs to be a shallow hole because wall thickness is .046/2 or .023.  Maybe one could use a smaller drill and sharpen after turning.  I am using this on the way it came off the lathe.   Position the foil on a block of wood and  run the punch a bit into the wood.  I folded six layers and punched them.  Was a bit much 4 might be better.   The outside edges can be trimmed after the bearing cap is tight.  

If I had drilled the .404 hole and sharpened from the outside the hole size would have be closer if not correct.  But when I got going I could see that the wall after drilling was thin enough that I did not need to sharpen it.

If I needed to punch leather or vinyl I might temper and sharpen the punch but its not needed here.

 

Update Nov 24 2021

Had the Atlas  10F spindle off to fix the thrust bearing so I had to reshim the bearings again.
Turned a new punch because I could not find the old one.  Used larger stock and put the taper on the outside as suggested above.  Made the hole a bit larger so foil does not run on the bolts.

The foil is a bit hard to manage.  Used elmer's spray adhesive to glue two sheets of pitmaster foil for shims that were about 3 thou.   These are much easier to handle.  I think I used 6 thou of shims on one side and 7 on the other front and back.