Settings for cutting acrylic please

[dreamcatcher]

Hi there
We have a LS3020 and have been having fun with it for about 6 months now. I've got the hang of cutting birch and just started to have a go at cutting 3mm acrylic with varying success. Please can anyone suggest what power and speed I should be using for engraving and cutting acrylic. I tried it at S 140 P 40 for engrave and S 8 P 60 for cutting. The engraving looks fine but I'm having trouble getting rid of the white marks round the edge. They look like scorch marks. I raise it 4 mm off the mesh with some spare off cuts of wood and that has helped but I think I'm still doing something wrong. I'm using clear cast acrylic and engraving from the back.

I also had a go at mirror acrylic today and some of it was ok but there were a few marks round the cut line that look like cracks.
I now have a HUGE bin of wasted material - this is a very steep learning curve ha ha!

Thank you.

Pamela

[Intri]

Hi there Dreamcatcher

I have a 60w tube and and can cut 3mm cast on speed 20 power 55

As for cutting (this is what I do) you can cut with the plastic coating off but I like to play it safe and cut with the protective film on.

If i'm cutting from a big sheet I like to hold it down with some sort of clamp, cut out my shape then gently remove it take off one side of the plastic film and put it back in and engrave. Or just make a jig after.

Try not to engrave then cut otherwise you will burn the dust to the plastic and it's a pain to get off.

Last but not least. Use isopropanol. Cut, engrave then clean. It will get rid of the misty marks round the edges of lettering and whatever you've engraved I like the stuff, other people might have a different method

I love engraving acrylic especially reverse engraving. gives a really good finish to your project.

Hope this helps

[dreamcatcher]

Hi Intri
Thanks for taking the time to reply. I'm having a bit more success with acrylic at last! The engrave is ok and I tried cutting at speed 6 power 40 and it looks better than before but I'm going to try your settings too.

Thanks for the tip about isopropanol works a treat!

Many thanks for your help.

[JamesW]

If you have problems with your acrylic getting cloudy or scratched, then isoprop is a great idea. If that doesn't shift the dirt, or if there's actual scratching, try Brasso. Yes, I know it doesn't sound like it'll work - but it does! It's saved my bacon a couple of times when there's been an annoying scuff mark in a highly visible place.

Interesting to hear about Intri's settings. I use speed 25 power 90 with a 60w laser - quite similar - but watch out - different colours of acrylic seem to cut differently. For me, deep purple often seems to be a problem. (But black sabbath is fine. And blue oyster cult... never mind.)

Cheers,

James

[Daven]

I tend to use 17 at 65.

Be careful using slow speeds and intricate designs when cutting as the heat builds up and the acrylic can easy catch fire!

Best
Dave

[dreamcatcher]

Hi
Thanks very much for the advice. I'm trying all different settings. So far I haven't burnt the place down - fire blanket at the ready though!

Any tips on cutting mirror acrylic?

[Daven]

Any tips on cutting mirror acrylic?

Much the same as normal acrylic, just a bit more power and cut it facing down. Good air assist helps.

Best
Dave

[dreamcatcher]

Thank you Dave.