I was doing some work for a friend last night and decided to try defocused engraving on a .25" piece he’s going to backlight…
The results were SOOO much cleaner. All my engraves on acrylic are going to be defocused from now on. I’d recommend the same to anyone:
Sorry to have to ask but it is the left side that is defocused and right not? Just to be clear. The left definitely looks smooth.
I was going to ask the same question.
Yeah the left is defocused. I didn’t clean either of them before this photo either. The defocused one is a LOT cleaner too.
The left one looks amazing! Well done.
How much do you defocus it to get that result? 
@davidgal2 It was .25" so I had to set it to .433". Worked better than I thought it would!
That is great to know. 
Thanks for testing and sharing with all of us.
Hokey smokes, that’s fantastic!
Thank you. I haven’t done anything with acrylic yet, but it is high in my list.
That’s pretty sweet! Have you done a comparison with a backlight, to show how it affects the translucency? Is the lighting more diffused in a nicer way as well?
I wonder how much clearer defocusing would be on extruded acrylic. I’m thinking of reverse engraving on the back and filling, leaving the paint fill protected on the back of the piece. Looking at this post I don’t think that idea would work, unless defocusing in extruded gives a clearer engrave. Perhaps playing with power or LPI would also change the look?
https://community.glowforge.com/t/time-for-an-escutcheons/8435?u=bill_laba
Woooof! That’s way more defocusing than I did in my acrylic coaster testing last month.
Nice work.
Have you noticed that the GFUI seems to build in defocusing for it’s “by color” options? If you pick a color and then convert it to manual it’ll give show you parameters (which I presume are the ones from the automagic setting) and I’ve been noticing that the focus distance is almost never the same as the material focus.
Did you have to run this item twice? once defocused to engrave, then a second time re-focused for cutting operations? Or is there settings in the software you can change for each operation individually?
Ive seen focus depth be somewhat off of material height for many materials on all job types (cut, score, engrave). It obviously seems to work well in this instance, so having it as part of the dialed in proofgrade settings makes sense.
Ive tried this before, but only as a second engrave to try to clean up the first focused engrave. Doing it as an initial engrave ended up way better than expected.
Focus height is set automatically to the height of the material based on the depth sensor on the head unless you specify in the UI a different height for each job (if you dont want it the height the sensor detects). I left the cut at the height detected by the sensor (default).
Not sure about how itll work on extruded, but it might actually be a bit clearer. Too low an LPI will undo the defocusing however, as the lines will be too far apart. This was at 340. worked great
I havent yet. It was for a friend and he was excited to take them home and test them out, but ill see if I can get him to take some photos
Wow!! What a difference!!
holy crud the left side is so nice
