Ordered the crapsman powder gun, but self isolation is VERY BORING. So I built one out of a pickle jar using a horror fright electric flyswatter as a high voltage source. Because I couldn't wait. A real hack job, but I did wash out the pickle jar even though it says it's "kosher", then I made it extra super kosher with some precious alcohol and acetone. Believe it or not this works & deposits a uniform layer on the PCB. Now I have to assemble the finest chinesium laser engraver and see what details are possible.
Pickle Jar, eat the pickles
Clausen pickles are good
Harbor freight electric flyswatter
FREE with any purchase sometimes
Sweep up by printer if you have a xerox
write a novel or discard the guts & use the tube
I tried another board with large fields, I see shrinkage afterwards along the direction of laser travel. Might need to color these in with sharpie in certain cases, or do the borders & use paint/tape etc. I don't see this as a big problem, as long as I'm not fixing little stuff I'm happy.
Burned one at 5% and 2200 mm/s and it's nearly perfect. But it's crooked & warped. Not going to bother wasting time on a pic. The software only accepts jpg, so I have to extract the image from the PDF. Then resize so it's right. The jpg is straight, but the print is way off.
So I'm trying Lightburn which imports PDFfiles, burning one now. The other possibility is the cable is getting hung up? We'll see. I can't get it to light the low power for testing size, but I used a big enough board to guess & it seems like it's going to work. I'd like to etch one of these eventually, since I have lots of acid just sitting here. FeCl
This is the ramp to check my focus, to the right is on the table, to the left is raised 3/4". Bottom line is 40% laser, 6th from the bottom is 15%. I still see smoke @ 15%, but I'm going to try it on the rest of the board.
So I shot this at table height @ 15% laser.
This is most certainly usable, I'd etch it but it's a mistake design I don't need. There's no voids or any of those missing spots you get with the paper peeling method. Just a nice layer everywhere it was intended to be. No guessing with the iron. Plus I'm washing my hands quite a bit with the leaky pickle jar powder gun. As soon as the real one gets here (movement now) this thing is going back to killing flies.
Laser power @ 85%, probably too high. Could be scaling issues since I had to convert the pdf to a jpg for the software. close traces are touching, I'm thinking from heat transfer to surrounding powder. I very much like the consistent and void free layer of toner this applies though.