new to laser engraving and cutting

[Sye05]

Hi, im using an ls3060 with 60w tube. Ive managed to sort my engraving issue which was due to wrong focus. So one problem solved but im having issues cutting ive reduced power to 25 speed is 12 but im getting chipped edges on acrylic. Please could anyone help with what im doing wrong thankyou

[Daven]

That is possibly reflections coming back up off the bed - I raise the acrylic by supporting it with 5mm spacers

Best
Dave

[Tom]

Yep sounds like backflash to me


Tom

[Sye05]

Thank you for getting back to me. What sort of spacers do you use? Could i sit another 3mm acrylic underneath.i really appreciate all the advice

[Daven]

I use magnets as they are handy to hold ply or mdf flat but you could cut shapes out of scrap that fit in the honeycomb

[Sye05]

Thats a good idea i will give it a go later and let you know how i get on thank you so much. Can i ask what settings you use to cut 3mm acrylic? Thanks again

[Daven]

I use around 15mm/s at 65% but that is on a well used tube and I don't remove the protective coating
Best
Dave

[TimBobTastic]

I was also led to believe that Increasing the speed may also reduce the backflash issues, although I have not had a chance to put this into practice yet....

[Daven]

Hi Tim - it would in as much as it weakens the cut so the beam has less cutting depth, reducing the power would also do the same. The downside is acrylic is not a consistent thickness across a sheet so finding the sweet spot could be a pain - add to that the many other variables that can affect the cut and it is easier to overpower and lift the acrylic.

Like most things there are downsides to this method so over time you find other solutions depending on the shapes you are cutting

The other way is to invest in or make a pin bed

Cheers
Dave

[TimBobTastic]

Pin Bed.... I read somewhere that pop rivets fit rather nicely in to the honeycomb to make an effective pin bed... I am going to have to try that one day....

Good point about acrylic thickness, I forgot about that... Not sure how, it has caused me a few problems.. lots of headaches and some scrap