Joe, I get really clean holes in plastic with a Unibit. I know
they can't use the normal Unibit, but you might try duplicating
the single flute and angle geometry of the bit.

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______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert
incognito.

I have a customer who bought a machine back in '05. Since day
#1, they have been trilling this material they call "Torlon PEI"
with a. 0.029" drill at around 10,000 RPM

The material is 3/8" thick and they have no problems making the
hole itself. I thought they would have to peck drill it, but
apparently not...

The drill rapids up to the surface, takes a controlled feed rate
from 1/16" prior to the end of stroke (clean through) and
retracts at rapid speed. Much like a CNC would but with a
simple, but highly controllable hydraulic feed control doing the
dirty work.

Now that every penny counts more, they found that the process
leaves a burr on the product that they have been removing since
day #1 by hand. They want to try and drill without getting that
burr..

Here's the kicker... The burr is at the entry side, not the
break through side...

My first thought was that they were controlling the feed rate
too late and that the drill was entering the material fast, then
slowing down and completing the stroke. They claim that is not
the case and that the feed is 100% controlled from entry to
breakthrough. They also claim that the burr shows up when entry
happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might
be causing the problem?

RPM or other suggestions, thoughts? Etc... Can't really go
above around 11-12,000 RPM on this application due to machine
limitations.

My next suggestion to them was to try and get a small
countersink bit but they are using a drill bushing to make sure
accuracy is held very tight. Can't use a drill bushing in that
case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


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