Thanks Wilber +1..
Looks like a 7inch 0.125 Amazon aluminum circle, a lathe center hole, a coat under and over
the printout with clear Polyurethane and it’ll be glued and protected from oily fingers..
The print out is a tiny bit bigger than 7inches but my printer warned me it was low.. only got yellow.
I’ve got an 18” and a 24”. Both can be an issue on small engines trying to get a sturdy pointer
set up, so it doesn’t become the error..