Awful edges on acrylic

[kreativkatie]

Aaarrrhhhhh!
I only got the laser in November, when the engineer came to install and train we got a small 5mm thick piece of acrylic cut with a really smooth edge using sp 10 power 75 ish. But I found on bigger products (which I'm mainly cut) this power causes it to ignite underneath. I slowly lowered the power and found it will cut through at power 36 with no ignition. Great, But... I have moved the speed to 6 or 7 and still am getting a poor quality cut, there are vertical
Ridges all the way along the straight edges (not so visible on round corners though?)?
I've checked my alignment and my mirrors are clean.
Any suggestions?

[Daven]

Sounds like the power is at the point where the ablated material/gas is causing it to kind of pulse.

Lift the material up a bit off the bed - better air assist and extraction can help. Make sure the running gear is clean and lubricated as well as that can sometime cause ridges.

Best
Dave

[kreativkatie]

Sounds like the power is at the point where the ablated material/gas is causing it to kind of pulse.

Lift the material up a bit off the bed - better air assist and extraction can help. Make sure the running gear is clean and lubricated as well as that can sometime cause ridges.

Best
Dave

Thanks Dave,

I had an engineer out last week as the bed was not level, he couldn't really explain the ridges, he suggested tightening the belt on the x axis(which I did) and said all the runners were all lubricated and clean/clear so that shouldn't be an issue. I always cut with the materials up off the bed using 3mm acrylic off cuts.

"Sounds like the power is at the point where the ablated material/gas is causing it to kind of pulse"
I'm being a bit of a thicket, sorry, do you think the power/tube is going? I've had the machine brand new since the beginning of November, A very basic calculation means I've probably used it for about 40 hours?

[kreativkatie]

Do you think I just need to up the power as I'm only running it at 36?

[Daven]

Yes - try more power.

You may have found a sweet spot where the beam is affected by the gas/debris coming from the cut - if may (this is just a guess mind) that this is degrading the cut until it clears and then builds up again. If there is no mechanical or optical reason then it is power. I get it occasionally when the mirror or lens needs a clean

Best
Dave