Homebrew PCBs

Hey All,
I needed to place an order with Enco recently and decided to order one of
their Pencil Die Grinders part # 801-1665 for $34.95 that had been the
topic on the list a few weeks ago. If it didn't work ultimately for milling
boards I figured I could always use another small grinder in the shop.

Here's a break down of RPM's I got at various air pressures-
40 psi- 34,000 rpm
50 psi- 36,000 rpm
60 psi- 38,000 rpm
90 psi- 50,000 rpm

My top rpm was lower than the 56,000 advertised which could be attributed
to manufacturing tolerances, my using a heavier lube oil than the
manufacturer did or maybe break in time... it did pick up rpm's after
running a few minutes. 
Runout on a 1/8" dowel pin clamped in the collet is zip, though there is 2
thousandths of lateral slop in the front bearing. I not sure at this time
if the slop can be adjusted out, I tend to doubt it.

Personally I don't think the grinder looks too bad, especially for the
price, time will tell how it works for milling.
Denny
PS.
Enco can be found at- www.use-enco.com