Here’s an edge-lit acrylic image I did of some motorcycle patent art. I think simpler may better than not for edge-lit acrylic, and save patent art for t-shirts. While I do love patent art, in image with sharper lines is going to have better contrast.
This picture was before cleaning up the dust and fingerprints.
I mean, if you’re going to print patents…
Is that cast or extruded acrylic? How did the edges come out for you?
It was some spare pieces I didn’t buy, so not sure wheaten cat or extruded. The edges showed some the perpendicular laser lines from cutting, but still fairly smooth. Turning off air assist usually results in glass smooth edges in my experience. We don’t have that capability, though I’ve talked with Danny about that possibility. I’m not sure if it’s on the radar.
We can try it. The thing that is a risk is overheating the lens and breaking it. We have replacement lenses. There is no risk to upstream optics or anything else.
I do like to be mindful of changes to equipment- we have a wide user base. This would be a mechanical knob and gauge that you can leave the “off” position and it won’t reset. We don’t have an established way to communicate updates to users on new developments, and many users really need the simplest click-and-go system possible. A new gauge you need to use can be intimidating.
We can try it any time though. If it busts a lens, that’s fine. I did note that the valve might be limiting the flow below what it is now, and that may be undesirable. We can test. Maybe I could just get a larger flow valve or compressor with more initial pressure.
If I can help with the in any way, please let me know. This isn’t an necessity by any means, more of a “wouldn’t it be moon” (tip of the hat The Beach Boys lol). It would be useful when working with small pieces that are prone to flying away.
OK I tried this back and forth for awhile. I couldn’t find an advantage to reducing airflow on acrylic- rather, it really wanted to burst into flames. And, from what I could tell, it didn’t actually change the cut substantially when reduced.
But it’s simply not necessary either. If your edge is wavy not smooth, that’s because the thermal lance is dragging and turbulent. I just slowed the cut down a bit and the edge glassified, even with the air assist flowing as normal.
Thanks for checking it out.
So, exploring more-
There are two subtle features here of note in the edge- vertical stripes called “striations”, and, typically near the bottom, the cut may sweep back, that’s “dragging”.
They are not the result of air assist. Nor at they from pulsing of the laser source. At 100%, Tarkin does not pulse (Pearl does, however). It is believed to be from gas venting out as it is cut in a cycle of vaporization making a bubble that pops.
Dragging can be countered by cutting a bit slower overall, without reducing power.
It seems like glassing the edge, and not getting the striations, may be cutting slower AND with lower power to get to the point where the acrylic surface around the cut absorbs enough heat to melt, but not enough to vaporize. By going slower just by itself, this might not melt the edge, as the beam initially slices through and then is mostly hitting the honeycomb.
It’s a surprisingly vaguely understood process, and this may not be entirely correct. Cast vs extruded may give different results, as well as other parameters (color, etc). I went back and forth for awhile.
The most standard test I could do was 10mm x 10mm square, standard surface focus. That’s enough to get the edge doing what it will do. Larger just consumes acrylic and I haven’t found additional value in larger test shapes…
I suspect cast would yield a glass edge better. Good info Danny.
hit it with a blowtorch and that will glass the edge as well.
