Big Laser Z Datum

Hey all,

Just a heads up that the auto zero on the big laser is wonky. I think that the actual bracket that holds the sensor got nudged up. When it zeros itself, it is not the correct distance, since the sensor itself got moved. This produces a lot of FIRE and bad cuts.

I had to leave quickly today, so I didn’t get a chance to fix it. I am going to take a look at it tomorrow and hopefully put the sensor back at the right height.

Until then, please use the little laser. I’ll give an update once I try to fix it!


WOO HOO! Alrighty folks!! I got it fixed! Pretty sure this is the best it has ever cut since the beginning! It was in fact the sensor assembly that got nudged up. I secured it better so hopefully that won’t happen again, experimented with the Z datum numbers, and then changed those numbers in the script that runs the program for the big laser. So it should all be ready to go when you start it up again.

Anyone who has been cutting larger jobs/things at specific speeds, you might want to do a few test cuts first before using your old speeds/powers, because I think you will find that you can cut through your materials faster and with less power than before. I’m thinking of you Bill and Brett.

For the few cuts I did tonight, I was able to double the previous speed and take a third off the previous power…!!! (For anyone interested, I was able to cut 1/8" acrylic before at 8 100 95 - and now I can nicely cut through at 18 70 65.)

Lastly, this also fixed the sighting laser’s error of a few millimeters from where the laser actually fired. It seems pretty dang close right now, so the sighting laser is a decently accurate guide again.



Due to the lack of rigidity in the sensor mount design, I have a feeling this will slowly happen over time. It would be great to do a monthly check using known values and the same material. Then adjusting things as needed.

I’d definitely be willing to do this. I would also like to teach you, Dustin, for sure since you are the FabLab warden. Perhaps the people who are “trainers” on the lasers, or maybe one or two other committed individuals, as you would have the responsibility of fixing it then :stuck_out_tongue: I’d like to keep the pool a bit small for now since it does involve altering the main script that everyone uses to load the laser.

How about a paint pen mark under the bracket that we can check? Anybody got a paint pen?

I had thought about marking it, and that would be a great idea, IIIIIFFFF it didn’t need to be accurate to .1-.2 mm for the focus to be correct.

I might mark a good range to start from if it does get moved in the future, the would be useful. After that, everything that happens is inside the program, so you really only move and position the physical piece once, and then change parameters in the program to get the focus right.

Just measured kerf at 0.005". That's amazing!