Diode lLasers - Under the Hood 04

Converting my RF CO2 laser to a diode laser was very simple....no puffs of smoke!!
There were many suprises as I took my first venture into the diode laser world. The violence and intensity of the blue light at the material surface was was 10 times greater than I had ever witnessed with a CO2 laser ....and that was from just 5 watts!!! Having owned a precision sheet metal business for many years, the light intensity was comparable to a welding arc and left white spots in the eye for several minutes after the briefest exposure.
Finding the focal point was reasonably straightforward but using black acrylic for this task seemed to indicate quite a large spot size . This immediately made me sceptical about cutting ANYTHING with just 5 watts. Perhaps engraving would be better but on a different material.. With little hope of success I proceeded with my normal CO2 engraving routine.

[@ramhornnn]

I've been waiting for this video for a long time. Thank you very much

[@krisknowlton5935]

Russ, several years ago, when I purchased my first 5 watt diode laser, the lasers had an adjustable lens. You had to screw the lens in or out to get the proper focus. As you are suspecting, the 5 watt diode laser does not cut very well. I stumbled on a three lens collumnator on Wish (e-store based out of China). The lens was only about $3 US, so I bought a couple of them. It made a huge difference. What took three passes to cut through went down to one pass. I think I might have another one laying around if you would like for me to send it to you to experiment with.

[@beakytwitch7905]

Laser focus collimator 😊

[@krisknowlton5935]

@beakytwitch7905 you are correct. That is the reason one needs to go back and proofread their comments. I have been hit by the old auto correct once again.

[@henrymach]

You *really* should use some eye protection with these blue diode lasers

[@SarbarMultimedia]

Genuine thanks for your concern. I do address this issue in the next video.

[@octoaquatics]

correct, we cannot change pwm on a diode laser.
too bad you can’t take them apart because i’d be interested in seeing the internal differences between the manufacturers. these laser machine companies outsource their laser modules so consumer have no idea if they’re all the same or not.
and you did discover that we have to set the proper focal distance before starting our jobs.

[@DerekWoolverton]

The way you're trying to do your dot pattern is kind of a kludge, because its also going to be dependent on what power level you set. You've sort of aligned your PWM period with your pixels, so each pixel gets one PWM pulse, but the PWM pulse is still not instantaneous (which is what would be required to get a perfectly proportioned pixel if the beam is indeed 0.1mm). At 30% power you're probably getting a pixel 0.13 x 0.1, which is not terrible, but as you go up in power, it gets worse. 0.15x0.1 at 50%, 0.175x0.1 at 75%, and 0.19x0.1 at 90% (basically a smear again with your test pattern). This presumes the dye is reacting across the entire beam even on the edges not exposed at all, which is probably not the case, but regardless, at near full power, its going to start stretching again. Countrawise, at lower powers and slower sweep speeds, you probably are going to get even closer to an ideal shaped pixel.