80W CO2 laser - Line Engraving Quality question

[ednisley]

@jkwilborn

wouldn’t expect any wobbles in the Y direction

If the lens is wobbling around while traveling parallel to the X axis, any motion in the X direction will be pretty much invisible: if the beam goes backwards or forwards, the trace will be marginally lighter or darker.

But if it wobbles in the Y direction, then the beam will burn to one side or the other of the center line where it should be, which could produce those worms.

Come to think of it, in Dot Mode a wobble in the X direction could produce irregular dot spacing, which is kinda-sorta what appears in the bottom track.

I’m not convinced, but it’s certainly worth checking all the doohickies on the laser head for a snug fit.

[jkwilborn (Jack Wilborn)]

You and I know the first thing to check is mechanics…

Much more likely a mechanical failure than an electronic one.

[reddotfactory (Chris Johnson)]

Hi Jack and Ed,

You guys are great.

The line interval on these latest results was 0.15mm. Gareth must have been from the previous thread, he has an interesting website https://laseruser.com/how-to-laser-engrave-slate/

I’m so glad you guys have raised the worm issue. I have no experience with lasers at all and don’t know what I should be expecting in terms of results. To give perspective the laser was £6k Sterling and it was new March 2022. However, I have not started using until about 4 weeks ago and was immediately struck by lack of quality on attempting to picture engraving.

I will investigate the mechanical setup further. There’s no way I would have know that the wobble you refer to should not be an expected result. I would have put it down to units limitations. Really appreciate your input. Thanks.

[jkwilborn (Jack Wilborn)]

These are two different types of slate… Notice one engraves light the other dark… These were done with the 2" lens.

This one was done on the fiber… this has a smaller dot, but the material, is generally the what sets the dpi limit … in the end it will be laser dot size and material that will decide the best dpi.

You are running the dot test in pass through mode, correct?

Hang in there… I’m sure we’ll get you going…

[ednisley]

@reddotfactory

lack of quality on attempting to picture engraving

Given a loose tube rattling around in the back, it should be awful.

With that snugged down, the results look pretty good and we’re quibbling about details.

The scan interval depends on the width of the surface damage in the target: 0.15 mm is an itsy too wide for the grayscale material, but might work fine in a different material.

At some point you should explore Dot Width Correction for images; I don’t have a lot of experience, but it’s apparently the ticket for crisping up the contrast:

Dot width correction?

It’s a new setting for images that is used to compensate for the fact that your beam has width. If you tell LightBurn to dither an image. On a 50% grey bit, it produces alternating on/off short line segments, like this: [image] If you draw the width of the beam, it looks more like this: [image] If you look at that 2nd image, the gaps between the lines are shorter now than the lines themselves, because of the shape of the beam. ‘Dot Correction’ is the total amount to shorten the line, t…

[jkwilborn (Jack Wilborn)]

This laser everything video talks to the Lightburn developer of dot width adjust at about 20:18 into the video… good explanation… also a very good video on how to set up the proper dpi for a any given material/laser.

The COMPLETE Photo Engraving Guide Part 1 | Fiber CO2 UV and Diode