In a message dated 9/1/2003 1:48:27 PM Central Standard Time,
john@... writes:
angle, so that one of the flute-tips is the lowest point, and run those at
30,000 RPM, with perhaps 150 IPM feed-ratge. Thus, the cutters are "free", as I
keep lotsa busted solid-carbide bits!
You can also grind off ALL the "flute" and make a regular engraver's bit of
the "cone end" of the 1/8" shank. This shape is much sturdier than a re-ground
drill-bit end, of course.
Jan Rowland
[Non-text portions of this message have been removed]
john@... writes:
> engraving PCB's for a while now, however the only bit that I have foundI simply save busted carbide drill-bits and grind the tips at a very slight
> that works really well is a M99 carbide spade bit from . . .
angle, so that one of the flute-tips is the lowest point, and run those at
30,000 RPM, with perhaps 150 IPM feed-ratge. Thus, the cutters are "free", as I
keep lotsa busted solid-carbide bits!
You can also grind off ALL the "flute" and make a regular engraver's bit of
the "cone end" of the 1/8" shank. This shape is much sturdier than a re-ground
drill-bit end, of course.
Jan Rowland
[Non-text portions of this message have been removed]