I have both a 40w diode laser and a 2W IR laser and am engraving a holster clip for a friend. The diode laser works very well with smooth lines but produces a not so shiny surface. The IR laser gives a nice shiny surface but the lines are very rough. Any help would be greatly appreciated in my desire to use the IR laser for the shiny surface if I can get it to produce smooth lines like when using the diode laser. See picture below. IR laser running at 80% 4000mm/min and using cross hatch and Bi-Directional fill.
You can burn the metal by over exposing to laser light. Have you tried to polish the result with a bit of citrus base cleaner, or even a cloth damp with break cleaner?
Is you focus depth the same for the IR and the diode? I find that slightly out of focus with my diode gantry laser gets the best results from powder coated tumblers.
10w
2400 mm/m
.1 mm interval (spot size is .1mm)
I also changed my LPI to 600 as it was at 284 and got much better results. Do you suggest going farther out with the laser or closer to the object being engraved in order to make it go a bit out of focus? I have to focus each laser at different heights 30mm for the diode laser (0.04 spot) and 23 for the IR laser (0.03 spot).
I find farther away helps soften the focal point.
You can add a clean up pass by setting a sublayer to LINE. I like how that helps smooth out the jaggies.
Ok that sounds great. After I increased my LPI to 600 from 284 the engraving got much better. However, now I have a bit of “ghosting” on the sides all around the edges. Not sure as to what is causing that. Maybe I need to slow it down a bit. After I increase my LPI I slowed down the speed to 3000mm/min and only used 60% power and the result is below showing the “ghosting”.
Sublayer of Line to the same mm/min and power?
Hard to say without having hands and eyes on it real time. I would go slower by 10-20% and at the same power lever for the cleanup pass.
Do you have some stability issues with the laser? I think I see some wobbles in the engrave. For flat work (not rotary) I suggest you use cardboard scraps to get you design and mechanical variables worked out
You can increase your overscan from 2.5% to 10% to relive some wobbles. Getting the belts and bolts tight is critical for long term precision, though.
Show us your preview screenshot with traverse movement shows, turned on. It should have a red smudge around the outside of the engraved portions.
No belts it is all gear driven on rails. Fox Alien 4040 XE Pro. The only thing I didn’t do was tape down the object that is being engraved. I just had it sitting there on my honeycomb. Ooops. Machine stability is great with this FA Pro. Here is the preview image.
I see the crosshatch. When you are not Cross hatching you are moving left/right for your major axis?
Slow down the speed by 25-50%. Do you get the same kind of ringing/shadow effects?
The first burn is left to right and right to left each swipe. I got the most jagged edge using only left right and no cross hatch. Adding crosshatch made it less noticeable. I don’t have enough material to do it again. I’ll have to get a couple more from my friend to test further. I already decreased the speed as you suggested but have no more area to test on right now. I will get more and repost the results. Thanks for all the assistance Jim. Can you briefly explain why more overscan would help? I reduced it to 1% thinking it would go less over the edge but maybe I have it backwards in my mind.
You may have issues if you use this value in your LPI/DPI calculations. I have a 10w stated as 0.06mm and a 40w stated as 0.14mm dot size.
1 Like
Overscan helps the stability of the laser at the end of the pass. The laser head, especially the IR has quite a lot of mass. To accelerate and decelerate turn around and change speed again is incredibly stressful. Extra overscan let’s the machine slow down and speed up over a longer distance. Short stop and go will cause vibrations, an effect called “ringing” that will leave various artifacts on your results.
2 Likes