Missing bottom lines


When I do a scanning job, almost always missing some line on the bottom. The scan starts from the bottomsite. I’am 99% sure that there is no backlash in the machine so I don’t think that it is mechanical. What can I do about this?

I don’t understand what you’re missing or what the problem is here with this picture.

Look at the o’s in ‘voor’ - the bottoms are flat.

In the fill layer settings, change the angle to 180, and that will scan top-down instead of bottom-up. This is very probably mechanical - if the lines are there in the preview, they are being sent to the machine.

And it looks as if it’s doing it to the bottoms of every sentence. Could maaaaaybe be a weird line interval setting, but probably not.

Were the circles in the corners cut with the laser as well? Those are showing huge backlash.

If it is mechanical why is it by every sentence than. On that moment the laser is only going upwards?

Is the source for this vectors, or an image? If it’s an image, and set to threshold, you might be missing the bottoms of text because of shading. For example, the e and s in this image, along the bottom, are not dark enough to pass a threshold cutoff:


Yes, the circles are cut with the laser to. But there is no mechenical backlash.

I think that it are vectors because I typed the text.

This is what i se in the preview. Jou can see that the OO 's are lower than the V and R

Cut a couple of small circles with LaserCAD, and then cut a couple of circles with the same size and spacing with LightBurn, and show the results. If they’re the same, then it’s not a software issue.

I’m not saying it can’t be the software, but it looks very much like a mechanical issue, so I’d like to be sure before I go looking.

The 4th line from the bottom (toestemming voor het … ) looks correct - the bottoms of the o’s there are not flat, so it’s doesn’t seem to be every line.

Oke, I will try some cuts with lasercad (I never used it before) and the same in FB and show it here.
Thanks in advance!


I did the test as spoken before and here is the result. Both are almost equal and heve the same deviation.
So, it will be hart for me to find the problem:thinking:

Because the circles are flat along the top and bottom, the problem is your Y axis. When the laser changes direction from going forward to backward, there is slack in the motion system that has to be taken up first before the head begins to move.

Check the set screws on the pinions that drive the belts for the Y axis, to make sure they are snug and that the pinions cannot move on the shaft. Also make sure there isn’t a lot of slack in the belt. It should not be tight like a guitar string, but it should not be loose either. If you have a shaft in the back with a coupler that connects both sides of the Y axis, make sure the coupler is tight on the shaft. Any of these things could cause this.

Thanks Oz fot so far. I will investigate all the thinks you mention.

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