Artemia Salina

There is a bit of slop where the cylinder slides on the rod,
and that's because I could only drill the .5" hole and it's
not completely straight, forcing me to turn the rod undersized.
I should be able to ream the hole oversize a bit and make a new
rod with a true slip fit. Once I get a reamer....

If you drill undersized and then single-point bore you get closer.
If you use a piece of drill rod for the rod, then try to match it as close as
you can get in machining the sleeve--that may be the way to get a good slip
fit.

Half inch, etc. reamers should be common on the used market locally in CT.

Frank Morrison