Laser cutting PETG?

[Paul K]

For the CNC machine I'm making, I'm using Molex Micro-fit connectors
for the connections between the servo motors and the controller board,
and I'm planning to mount the connectors in a panel made of PETG with
a thickness of 0.1". PETG doesn't contain chlorine, so I'm hoping
that means it can be cut in the laser cutter (Pololu routinely cuts
it: http://www.pololu.com/docs/0J24/3#petg). Is there anything about
PETG that would preclude cutting it in the laser cutter at the space?
If so, I'm not wed to PETG (I picked it simply because that's what I
have on-hand), so is there another material that would work? The only
requirement (dictated by the Molex connectors) is that it has to be in
the range of 0.05" to 0.1" for thickness (which rules out wood).

Incidentally, the reason this needs to be laser cut is because the
panel cut-out is not a simple rectangle or circle but rather a series
of rectangular cuts (see http://www.molex.com/pdm_docs/sd/430200200_sd.pdf).
The widest part of the opening is 16.89mm (I'm mounting 8-conductor
connectors) and the smallest notch is less than 2mm wide, so doing
this by hand is very difficult (I know this because I tried!).


Thanks,
Paul

[Michael S]

YOu guys may have a better laser cutter, but here at the arch department I recently wanted to laser cut PETG and was told not to, because it could melt and at the very least create some color issues and bad smells. Acrylic is generally better....but if you are up for experimenting it could work, just be careful. It doesn't release any harmful chemicals like some plastics do I believe.

If it does laser cut badly, you could try using the laser cutter to etch the surface just mildly and then use a cutting tool over the marks, that way you have the nice marks but don't ahve to deal with melting/smells/ etc. I've done this with various materials that I wanted to be cleaner than the laser cutter would allow.

Michael Senkow

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Michael H. Senkow                (906) 281-4672

University of Michigan, Ann Arbor

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Michigan Technological University
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[Nate B]

On Apr 5, 4:07 pm, Michael S <senk...@umich.edu> wrote:
> YOu guys may have a better laser cutter, but here at the arch department I

CO2, 100 watts. It'll definitely cut the material, but nontoxic stinky
is still stinky. We've got the mother of all exhaust blowers on the
machine, but that only helps until the piece is removed from the
chamber! I'm seeing recommendations to wash it after cutting, leave it
outdoors for a few days, and consult Derek Lowe if you need adjectives
to describe the fragrant aftermath. PMMA is sounding better all the
time!

> If it does laser cut badly, you could try using the laser cutter to etch the
> surface just mildly and then use a cutting tool over the marks, that way you

Geeeeeeeee-nius! And if your cuts are straight, snapping it along
those score-lines is probably trivial. A zero-force implement on a CNC
gantry is the best layout tool ever...

> On Tue, Apr 5, 2011 at 12:37 PM, Paul K <p...@whirlingchair.com> wrote:
> > have on-hand), so is there another material that would work?  The only
> > requirement (dictated by the Molex connectors) is that it has to be in
> > the range of 0.05" to 0.1" for thickness (which rules out wood).

I'm fairly sure there's a 1/8" sheet of PMMA in the flat-stock area
just waiting for a use. I snagged it last time I was at Alro, just to
have on-hand for such needs. If it's suitable, have at!

-Nate-