Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list  

Subject: Re: [Homebrew_PCBs] Re: Looking for a source of those RINGs on PCB drills?

From: JanRwl@...
Date: 2006-07-26

In a message dated 7/25/2006 3:42:54 P.M. Central Daylight Time,
stefan_trethan@... writes:

What sort of grinder do the diamond wheels need?



ST: I can't answer your question by specifying a "usual grinder-motor"
which would be suitable, except to say it'd have to be one with very good
bearings, well balanced, so smooth-running, and I'd want at least 6000 RPM.

I made an arbor with a 12.7 mm dia. shank, which accepts 100 mm dia. X 3 mm
thick diamond-rim wheels (3 mm of O.D. is diamond-compound) and I use that in
my vertical mill ("Bridgeport" type mill). This makes it possible to do
relatively precision grinding by holding the bit being ground in a collet
fixture or vise on the mill-table, which can be moved with 0.0005 inch precision
fairly well in the X & Y directions. But I can get this spindle on up to about
3500 RPM before I am afraid to take it higher, lest the machine vaporize!
Jan Rowland


[Non-text portions of this message have been removed]