Urgent help needed!!!

[Nick Syrax]

I'm cutting some ornaments from 1/4in acrylic on my 40watt Zing using 10/100/5000 speed/power/freq and it seems as though the laser is either not going all the way through or it's re-melting. Thankfully I only did 5 of the 45 needed but they need them by Saturday night, which isn't a problem if I can get this issue licked. Any ideas? Also, does either Home Depot or Lowes carry acrylic sheets, and if so, can they cut them to sizes? I need 1 more sheet for the job and don't have time to order, if they don't, do you have any recommendations? Thanks !!!

[Joe Pelonio]

I have 45 watts and use speed 8 for 1/4", I would try setting yours at about 4.

Both places have it in various sized sheets, and will cut to size. Just watch whether it's cast or extruded, for ornaments cast gives a better finish when engraved, more like etched glass.

[Nick Syrax]

I'll try that, thanks SOOOOO much! I always know I can rely on the awesome members of this board for help and advice!!!

[Dan Hintz]

And make sure your focus is correct (for anything more than about 1/8", I'll focus into the material about 1/3rd of the way) and air assist is turned on and at the proper pressure.

[Nick Syrax]

What do you mean by

(for anything more than about 1/8", I'll focus into the material about 1/3rd of the way)

Do you mean I have the table lower? Thanks!

[Martin Boekers]

What do you mean by

Do you mean I have the table lower? Thanks!

You have to slightly raise it. Air assist is extremely important when vector cutting.
For acrylic google for plastic companies locally. Most sign shop should have some and may
give you or sell you some small pieces. Just make sure it isn't lexan or a polycarbonite as
those are a mess.

[Doug Novic]

Nick,

Lowes and HD carry acrylic. I've cut a bunch of the 1/4" and it takes about three cut passes with a 60 watt at slow speed and high power. I also keep the acrylic elevated off of the table by 1/16" (plastic laminate shims). Bring the table up a bit as it runs the last cut and it falls through clean.

[Allen Isakson]

Doug what kind of laser do you have. Iv'e got a chinese 60 watt and i cut quarter inch all the time single pass with edges looking like glass. Just curious why the three passes.

[Rodne Gold]

Actually , it's power density and spot size that matters , a large spot size or misaligned spot will have much lower power density and it wont promote the thermal shock and vaporisation needed. Think of trying to puncture a ballon with a pin or with a wooden dowel , the pin will work MUCH better. Your 60w might have a power density of 1500w/mm2 and another with a 60w source but with a BIG spot or unfocussed spot might be 1/5th of that. Another analogy , think of a bic lighter with a 100watt flame and a butane soldering torch with a 50w flame , burn a hole in a piece of paper with each , both will work , but the thin hot blast flame of the torch wil burn a neat hole much quicker than the bic.