9" square mirror engraving with the Winnipeg Jets logo.
Turned out better then I expected. Mirror is looking at the stipple on my ceiling if your wondering why it looks bubbly.
What are you engraving with?
3 watt laser.
Cool. So you’re burning the back side?
Yes on the back side and the image mirrored horizontally.
Wow, looks like a cool way to make a little pocket money right there. Next time you make one could you share your settings, I think I need to give this a try.
I used image2gcode
min 2
max 255
speed 4000 mm/min
added start code for setting acceleration up to 1000 for x y
That SOA mirror looks great. Miss that show…
@Leo69 can you explain a bit how that optimized raster works for skipping white space…
If I understand I think that if I put 75% in to threshold number it should ignore everything under 75% power?
I never really used the threshold setting but I think you understand it correctly. Allows you to filter out gray levels.
I can confirm that is not how it works… I tried 75% and 0 neither produced the proper result.
I didn’t code that feature so I’m not familiar with it. I tried it once but I got better results by doing a full rsster engraving. The problem for me was that my acceleration settings were high for the pixel by pixel engraving so every time there was white space in image machine would speed up too fast and when it got past the white space there would be dark areas where the deceleration took place.
I don’t rush raster engravings. If something needs to be done quickly them I’ll convert to a line drawing and use dxf2gcode instead.
Yes I am learning fast that they are best done slow with high acceleration for best quality.
Here is the most recent one of the machine in honour of the Jays making the post season.
1800 mm/min
XY Accel 1000
So this question is to any who may be doing mirrors…
I was watching some YouTube videos about engraving mirrors and it seems they burn all the “mirror stuff” right off. Mine seems to leave a semi transparent sparkly sandpaper looking texture after the engrave.
Now is this the laser just doesnt have to juice to get it all off or do I need to slow it down. I have been running at 1800 mm/min. And I bumped the Current on my laser from 1.7 (as per @Leo69 awesome instructions) to 2.0 since the DTR website show my laser can handle about 2.5 or 2.6A. That seemed to maybe make a small difference but hard to tell visually.
One type of mirror from Rona (the ones in the pictures) engrave pretty good. But I bought 12" x 12" mirrors from IKEA and the do not engrave nearly as good. The backing on the IKEA mirrors is a lighter shade of gray. Could that be the difference? They are really cheap mirrors (the IKEA ones)so I would be surprised if the coating is thicker.
Just looking for ideas that I may not have thought of… Really starting to contemplate a 60 - 100 watt CO2 addition. I am loving this laser stuff lol
Edit: Wonder if the G2 lens would be worth the money for the increased power.
Under the advisement from Jordan at DTR I bought the G2 lens. Gonna give that a shot.
He also mentioned that these cheap Chinese “laser drivers” are actually LED drivers are no good for the lasers and suggested buying a real driver.
The G2 lens is more efficient but I’ve read that it produces a slightly larger spot size so you may sacrifice some detail in your engravings, probably not enough to notice. Laser and LED drivers are both constant current drivers but I’m guessing a higher quality driver may have less ripple. I’ve hooked mine up to my scope and didn’t see lots of ripple but there are multiple iterations of this board on the market so I can’t say they’re all equal. I’ve been using mine for about two years and it’s working fine for me. If you really want more power then I’d suggest a driver from eBay seller x-wossee and maybe the nubm44 laser diode from dtr. That’s a 6 watt beast. That combo will be about twice as powerful as what you’re using now. If mirrors are you’re main projects then find some with a darker backing. The darkness of the material has a HUGE effect on power requirements. Light reflective materials will always be harder to burn.
Gonna try the lens first see what happens. I read to spray the back of the mirror with flat black paint and that should solve my issue.
My next upgrade will be to a 80-100 watt CO2 laser if anything.
Laser paint ablation is the method I use for PCB etching but be advised that it produces some pretty toxic fumes. I wouldn’t burn paint without proper ventilation for sure.