"Ignoramus4117" wrote in message
...
On 2010-09-01, Karl Townsend wrote:
On Wed, 01 Sep 2010 16:25:07 -0500, Ignoramus4117
wrote:

On 2010-09-01, Karl Townsend wrote:
On Wed, 01 Sep 2010 13:33:29 -0500, Ignoramus4117
wrote:

On 2010-09-01, Karl Townsend wrote:
On Wed, 01 Sep 2010 11:48:02 -0500, Ignoramus4117
wrote:

I was making something on the CNC mill last night. It is a little
block that I would clamp to the quill of the mill, so that I would
attach the Loc-Line coolant line to the quill. That way the coolant
would follow the cutting tool as the quill is raised or lowered.

Anyway, as part of that, I had to drill a deep hole (comparatively).
I
used a peck drilling cycle and it worked, but took way too long, with
withdrawal of the tool and lowering it down, etc.

So I wanted to double check what is the recommended procedure for
deep
drilling aluminum.

My feeling is that at the given RPM of 2400, I should have used a
much
more aggressive feed rate than I used.

nobody giving you numbers. I'd go 8 IPM and peck of .125 (1/2 D) if
its a 1/4" drill. But I got dials to quickly change feed and speed,
no
doubt an adjust would be in order on part one. Don't consider me the
definitive expert on speeds and feeds - I do it all by feel.

Karl, I mostly do it by feel too. I will get a piece of junk tonight
and will practice somewhat if I have time. Thanks for the suggestion.

i

on second thought, i go a full D in AL, 1/2D in steel per peck. Or .25
for 1/4" drill, etc.

But them, I would have long stringy chips hanging on the drill bit,
beating up loc-lines?

'Xactly the problem.


Karl, what about this routine (with copious coolant): drill a small
increment, then dwell the drill for a small fraction of a second to
break chips, then continue. That would break chips, right? I could
literally stop the Z axis movement to dwell for several times per
second. Would that be enough? Withdrawing to SafeZ every time is very
time consuming.


Are you using a peck drill g-code or your own routine to simulate a peck
drill cycle?

It should retract at max speed, which makes a difference.