The Laser Thread

[Ken H>]

OK, here's the blade I engraved this morning - the look blacker in real than the photo.

From right to left and all at 30kHz:
1000mm/sec; 75% power; 10 passes
500 mm/sec; 75% power, 10 passes
300 mm/sec, 75% power, 20 passes
100mm/sec; 90% power; 10 passes

The deer head/text on bottom was done with the OLM3 10 watt diode laser with blade spray painted black, engraved, then paint washed off with solvent. It seems like the diode laser "burns" the paint into the top layer of the metal for it's not very deep, but I've never had a problem with engraving wearing off. The Fiber laser actually removes some metal for a deeper engrave. Takes a good bit of sanding to remove the engraving.

 

[Drew Riley]

For sure $300 is a bit pricey for the rotary chuck, my rotary chuck was $129 off Amazon. Have you checked the scale on your laser yet? I mean when you engrave a 100mm square, is it actually 100mm on all sides? My laser is not. I just watched a couple of calibration videos, this one this morning and I do like this guy's videos:

Here is one from the Lightburn folks that's good but takes a different route to calibration:

I plan to go thru the calibrate steps today. It seems all the fiber lasers are Galvo type, and info for one brand is pretty much valid for other brands, and power from 20 watt to 50 watt is just a matter of how long to engrave.

You mentioned deep engraving - I had NO interest in that at all when I ordered my laser, but after watching a few videos it's something I might like to try - just to try. Us old retired folks need something to fill our days {g}. Those coins can take from 1 to 2 hrs to engrave - boy that's a long time. I'm really amazed how fast this 30 watt laser is to engrave text compared to the 10 watt diode laser I've been using - and the fiber does a MUCH better job of engraving.

For the SS blades I've tried the settings are pretty much the same, something along the order of 500mm/sec at 75% power, 30Khz freq, and 0.1 line interval using "Offset Fill" for the text. I'll do a followup post later today with a couple of images and actual settings. Brass and Aluminum are giving me problems. The other day I did a couple of really good engraves with text (14C28N) on a .020" brass strip. I didn't write the settings used down, and now I can even get brass to mark at all. Not sure what the deal is.

edit to add: this seems to be a pretty good video explaining all those timing settings shown in LightBurn with no real explanation. Not sure it's really needed to be calibrated, but it does a decent job of helping my understanding.

I do still need to check the scale on my laser. I know it's also recommended to check focal length by sight/sound, though I've just been relying on the factory "dot" alignment, and it seems to be accurate enough. I definitely need to dig into some of this stuff a little more in order to optimize my settings and results. I'll check out the videos you linked. I've also been watching "Laser Everything" on YouTube. He's got a lot of good videos.