On Wed, 8 Jul 2015 18:40:46 -0700 (PDT), "
wrote:

On Wednesday, July 8, 2015 at 8:34:26 PM UTC-4, Lloyd E. Sponenburgh wrote:
" fired this volley in
:

Not all that large, but big enough that I would drill a pilot hole if
using a regular drill.

I might 'pip' the hole to make sure it started without any vibrations, but
pilot? (I assume you mean full-depth) With THAT small of a bit?

If my machines can't hold center better than that, I'd better quit or
rebuild their spindles! G

Lloyd

The pilot hole is not to make sure that the machines hold the center . It is to eliminate the pressure needed to have a decent feed rate. On stainess as Eric describes it in his message, it makes a huge difference with normal hobby grade drill presses. If you do not do that , you end up work hardening the stainless and or stalling the drill press.

Sure if I buy an industrial grade drill press, it is not necessary. But this lets me use a cheap ( less than $600 ) drill press. I just can not justify spending more for a drill press since I do not do production work.

Dan

Dan

Very well stated!!!

Gunner