Deep drilling aluminum

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.
i
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On Wed, 01 Sep 2010 11:48:02 -0500, Ignoramus4117

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

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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
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On Wed, 01 Sep 2010 13:33:29 -0500, Ignoramus4117

on second thought, i go a full D in AL, 1/2D in steel per peck. Or .25 for 1/4" drill, etc.
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But them, I would have long stringy chips hanging on the drill bit, beating up loc-lines?
i
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On Wed, 01 Sep 2010 16:25:07 -0500, Ignoramus4117

'Xactly the problem.
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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.
i
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What's that Lassie? You say that Ignoramus4117 fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Wed, 01 Sep 2010 22:50:27 -0500:

If you look at the parameters in your controller, you should find one relating to G83. You should be able to have it do just as you describe. On the controllers that i use, the parameter is called "G83 high speed".
--

Dan H.
northshore MA.
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On Fri, 03 Sep 2010 01:07:43 GMT, snipped-for-privacy@privacy.net (dan) wrote:

=========I just hacked another cnc utility. This one generates the G-code to "pulse drill" to produce very small/fine chips that will feed up the flutes when deep hole drilling. I placed this in the public domain. see http://mcduffee-associates.us/cnc_related/PULSE.ZIP Uses only the most basic G-codes so should run on most controllers. Down side it is all inline code so the file is long.
User will need to provide the start and end block code and locate the drill over the spot where they want the hole. It is text based but should run on most any version of windows -- no dos box required. User must input a number of items on screen.
Ig -- check your email - I sent you a copy of the zip file as an attachment.
Enjoy -- any suggestions/feedback appreciated.
-- Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).
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George, I unzipped your zip file, it is pretty clever , very nice.
I will try to do the same as a G code subroutine.
i
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