PDP 8 panels. Feedback

Chuck Guzis cclist at sydex.com
Tue Oct 27 13:05:42 CDT 2015

On 10/27/2015 10:52 AM, Jon Elson wrote:

> You CAN use an end mill in a drill press if you are careful.  You get
> no self-centering, so the work must be **SECURELY** clamped, as the
> cutter may try to walk.  But, you'll get perfectly round, smooth
> holes. Twist drills tend to wander and make triangular and slightly
> helical holes.
> Obviously, you can only do this with small size end mills in a drill
> press.

A good sharp forstner bit, by its very construction guarantees perfectly 
round holes--and it's not self-feeding, so you can cut as slowly as 
you'd like.

Awhile back, I made a tape lubrication jig consisting of several pieces 
of 5/8" OD brass tube with small holes drilled (think #70 drill) mounted 
in 3/8" acrylic with a second 3/8" piece to form a bottom.  Absolutely 
water-tight fit with no adhesives--the tube was simply press-fitted into 
the round holes. The bottom was attached to the upper piece using 
stainless 4-40 machine screws.  It worked fairly well.


More information about the cctalk mailing list