Advice on cutting 2mm PETG

Hi

I am using an Omtech Turbo 756 (60w). I cut circular discs out of 2mm PETG and having a few issues and looking for advice. I can get nice clean cuts on the most part, however there are still ‘horns’ on each side of the plastic discs, a slight lip which i am currently taking off with a de-burr tool.

I’ve set the focus (and tried alternative bed heights), all speed and power settings, everything from 5mm/s to 40mm/s and 10% power to 40% power in all combinations. I’m wondering if it could be worth getting a new lens? Does anyone have any experience with 2mm PETG plastic? Alternatively could this be a bed issue? I am using the stock honeycomb style bed, maybe a knife style bed is best?

Thanks!

In this image you can just make out the slight lip around the outer edges, this is what i remove with a de-burr tool, but ideally want to just eradicate with a clean cut.

I really can’t see what the issue is from the photo.


Are you running air assist?

I don’t run air assist with any pressure (except to keep lens clean), if I do I get some strange formations on the acrylic that sound like your description…

Good luck

:smile_cat:

Sorry the image is pretty bad! On the outter edge there is a slight lip, a kind of horn the whole way around which i have to trim off, its tiny, but its there and can’t be.

I have air assist on (using Lightburn), its just an on or off switch, maybe i’ll try without it?

Some things, and I noticed it quickly when doing acrylic is the heated acrylic seems to get distorted before it solidifies. This left some anomalies I had to manually remove…

In theory, you should always have some air assist to eliminate or lower debris on the lens. Most of us call this a low pressure mode. When the air assist is enable on the layer, we get full pressure…


I’d give a quick try on a few pieces to see if less/no air would benefit your operation. Keep an eye on the lens. Should be a cheap/easy test.

Good luck

:smile_cat: