"AncelB
mosaicmerc@... [Homebrew_PCBs]"
> I use resharpened carbide in my dremel 395 with 1/8" shanks for PCB
> work. They work fine....I go down to around 0.31 mm. I can go smaller
> but bit breaking happens every 10 holes or so.
Me too, but I rarely break bits since I switched to a home-brew drill
stand that seems to eliminate any "hand wobble" from causing breakage.
My CNC machine can drill lots of holes with resharpened carbide and a
Grizzly pencil-style die grinder.
Perhaps rigidity in the holding of the dremel is more important than
runout? Or at least, ∗lack∗ of rigidity is more common as a cause of
breakage?