Hi'all, I needed a bunch of soft wood discs whose dimensions doubly did
not match my hole saw,so a make-do lathe was called in order. The centre
whole had to stay below 4mm and none of my cheap hole saw OD was close
enough to what I needed, that centre bit was 6mm anyway.
It's a wreck of a battery powered drill mounted onto a wooden board
scrap by means of an angle plate. Power comes temporarily from a random
IT PSU off the junkbox with 12V being below the nominal 18V of this
Mabuchi RS-550 "engine", but it did the trick.
I clamped a section of fence post angle iron together with the drive in
my vise so I had a tool rest for the chisel.
It wobbled way to few rpms and the M4 threaded rod was plenty weak for
having no tailstock supporting the far end but with adequate care, some
curses and prayers the job went fine.