On Sep 25, 3:54*pm, Winston wrote:
On 9/25/2010 12:19 PM, Ignoramus10035 wrote:

eBay is full of those:
* * *http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide
or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. ...

You need to adjust your feed rate so as not to exceed
a reasonable chip load at lower RPMs but they work great
particularly on nasty stuff like fiberglass.
....
--Winston

I've used them with a pin vise to make a hand-powered bow drill when
the Dremel at work was broken. I couldn't quite locate the PC board
well enough on the CNC board engraving machine to redrill the holes
larger without breaking bits.

Their main limitations are spindle play and chuck centering. They
worked fine at spin-with-the-fingers speed and a fairly coarse feed
pressure.

There's something odd about making a stone-age tool to solve a CNC
problem in a semiconductor factory. I had some spare round boards for
the flywheel weight and didn't have to grind a hole in a flat pebble.

jsw