@BaitMaster those are interesting!
Good point re: drill imprecision. Currently I make all my internals with machine/screw length drill bits, clean with a reamer, tap, and on clear pieces, sand and polish. It's the clear materials where I really want this to work. Here you can see the quality of the interior finish after being reamed (and run through the ultrasonic to clear off cutting fluid), the exterior has been taken to a reasonably high polish, so all that spiraling and texture is on the inside:
View attachment 81116
The issue isn't oversized holes, more that the reamer was visibly low compared to the drilled hole, and really had to "rise" quite a bit when I advanced it into the hole with the tailstock quill. In fact, I think I see a similar lift with most of the drill bits as they start to bite the material. How low? I can try to measure tomorrow, but this image may give an idea:
View attachment 81117
Now, I did cut down my most problematic reamer shank yesterday so TBD if that helps. For reference, before and after:
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