Acrylic Engraving/Cutting: What does 600 vd 1200 DPI do?

[Gary Gilbert]

Hi again most helpful folks . . .

Having a great time with the laser!

On Acrylic: What does changing 600DPI vs 1200DPI do to engraving?

I'm noticing some shoulder on the engraving.
Any way to minimize that?

Also, would you recommend say 2 passes at higher power or 3 passes at slightly lower power?
(e.g. 3 passes of 18/100 vs 2 passes of 10/100) - not they get about
the same depth. . .

Thanks,

Gary

[Joe Pelonio]

On the Rowmark type material with a lot of large areas engraved 600 dpi can actually cause the material to warp from the heat. The density of the firing of dots will make it go deeper but also heat it more.

Unless you have a specific requirement for depth, for paint fill,
making a part, or perhaps doing a wood veneer inlay job, you should not have to make more than one pass. That doubles the run time. 400-600 dpi should still be enough.

BTW I rarely go over 400 dpi on anything. I have gone to 600 on a few photo jobs on anodized aluminum but at lower power. I have never used 1200 dpi except once to experiment. Unless your artwork is at least 1200 dpi it's not going to look any better anyway.

[Mike Null]

Gary

I never use more than 500 dpi for plastics. In fact, the only place I use 1000 dpi is when I'm trying to get additional contrast on light woods.

If you're trying to remove the 1/16" you mentioned in a previous post several passes will be required.

[Gary Gilbert]

Thanks guys. Right now I'm at Speed 18, Power 100, 3 passes and get the right amount removed. I determined that I need to etch about 0.05 wider than needed on the outside edges. Then, I pull the vector in about 0.05 from the edge for the final cut, as if I just used the outside, I hit the very edge again, and some melting occurred, and and extra cut was necessary.

There is some shouldering on the edge of the center (un-rastered part) that occurs, but seems ok for now.

The 1200 DPI would then go deeper on a vector cut, but cause more melting? I'm curious about the final cut and whether 1200 DPI would be good.
Also, on rastering, if I should go down to 400 DPI.

Thanks to you guys on your replies!!!!

Gary

[Joe Pelonio]

Gary,

Just give it a try, experimentation often will get better results than listening to someone with a different machine. I use 600 dpi when cutting acrylic for a smooth flame polished look to the edges.

I definitely would suggest 400 dpi for the rastoring.

As a rule, use the least power, highest speed, and lowest dpi that will do the job, in order to save time (time is money), eliminate excess melting, and warping of the material from the heat.