On Wed, 01 Sep 2010 12:38:25 -0500, Ignoramus4117
wrote:

On 2010-09-01, Gunner Asch 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.

i

From the OmniTurn users guide...

G83 Zn Kn Fn Rn Ln Cn


G83 is what I used too,


In G90, absolute mode: Z specifies the end of the point of the hole
from the part Zero.
In G91, incremental mode: Z specifies the distance the tool will travel
from the starting point .

Start location: Position the drill where you want the first drill peck
to start. After the first peck the
drill will rapid out to the R location, and then back to where it
started less the C value.

K specifies the depth of cut per peck.
F is the drilling feedrate in inches per rev or minute depending on
whether you are in G94 or G95.
R is the retraction plane, the tool will rapid back to this location at
the end of each peck. Default
is the starting point of the cycle
L is the rapid travel feed rate for the retraction move, noted in IPM.
Default is 200ipm
C is the clearance distance left when the drill returns to the cut.
Default is .02?

Yeah, I used this, it just took seemingly forever.

I will try to practice on a piece of junk tonight, with higher
feedrates.

i

Whats your max feed rate for retract? And what do you use for drilling
feedrate? You can be fairly aggressive on aluminum.

And you can go fairly deep with each peck, particulary if you are using
a nice sharp parabolic and coolant.

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)