I have a cnc'd mini mill with a belt drive spindle.
I'm trying to make precise hole (or as close as possible) to .375" in half inch polycarbonate.
I have a .375 reamer, .374 and a .373
Currently I am trying with the .373 reamer. I have pocketed a thru hole with a diameter of .370". The reamer GCode has a plunge feedrate of 4. When I run the GCode the reamer chatters and squeals its way through and the resultant hole is way way over sized.
I have the reamer as far up into the collet as it will go and I put a dab of oil around the hole before starting to ream. The spindle is running pretty much as fast as it will go.
What am I doing wrong
Thanks for all help