Trying to focus my laser but running into issues

Hi folks,

Laser was working find last week but now when I try to focus the laser I’m getting these results:

Has anyone else ran into this before and know how to fix it? Is my laser messed up?

If I select one of those lines manually and try to run a paper cut job, the laser moves around but it doesn’t even come on!

You have to do this multiple times and take the best line to get the perfect height.
I guess this could happen if the offset or workpiece height is not correct.

Manual focusing is not that hard, try it to get sure your settings are able to cut your model.

1 Like

I’ve spent a lot of time explaining this in other threads, but here’s the short version. Paper is hard to burn consistently. There’s an initial part where the paper heats up but doesn’t show anything, then it quickly darkens followed by cutting through.

Unless you are trying to do engraving on paper, which is notoriously difficult, then don’t worry about it. Just pick the thinnest line. If you’re not given the option to then turn on manual focusing. Or calibrate using wood instead.

The reason some lines don’t instantiate a burn has to do with focus, flatness, speed, power, color of paper, and other parameters that all have to be pretty spot on. If you need to engrave that you need to do lots of tests to dial in the exact parameters which are finicky.

1 Like

Ah ok. When I first got the machine a few weeks ago, I calibrated it on cardboard and it looked fine.

I guess I was expecting to see the same on the paper. I was able to get the laser to come on using the default vector profile but it’s burning the heck out of the paper.

Initially when the laser wasn’t coming on I was using the recommended settings for paper but I guess the work speed is too fast?

On a different note, auto focus has never worked for me. It always fails and I have to calibrate it manually. Is that normal as well?

Maybe this will help explain why albedo is the reason why

I disabled autofocus, manual focus is the only way to get consistent results in my opinion. On my machine autofocus keeps running itself way too high or too low.

1 Like

Thanks for your time Brent!

I almost only ever use autofocus. The only time I don’t is when I have an object that I just can’t measure the thickness properly with my digital calipers. (If you don’t have digital calipers you really should for all 3 functions) It’s much faster than trying to figure out the focus manually and see the smallest dot.

I’m not sure why you’d be getting inconsistent results. If you’re getting consistent z-height with cnc or 3d, then laser shouldn’t be any different.

I agree the auto-calibration is flawed and doesn’t always work, but once you figure out what the correct offset for your laser head is it should work fine and it should never change. Definitely works better on plywood or cardboard than white paper. Some people have had better success with enclosure lights off.


Oh. You might be onto something there. I’ve only ever tried to focus it with the enclosure lights on. I’ll try turning them off next time.

For now I did the manual one and it seems to be working with the default vector profile. If I try adjusting the speed at all, the laser never comes on.

I have noticed that it always starts with the outer perimeter of the image. Seems like it would make more sense to start from the center to have to most stable work.

Another question. Is it normal for the laser to mark up the laser grill platform or show I be putting my work on top of something?

Apart from from the aspects you mentioned brent, when cutting card and paper I’ve found the moisture content has a huge effect. Drying some card stock I was using turned a nightmare of a job into a doddle. Please excuse the colloquial UK English.

1 Like