When I run a job on the Falcon 2 40 W it keeps shifting side to side and I get distorterd engraving and cutting. For example the text in the file called offset drifts side to side. It is somewhat odd since the rectangles seem to remain aligned. In the Happy Birthday picture everything seems to be distorted side to side including the perimeter cut which is supposed to be round, but comes out narrower in the direction across the laser bed. Previously I was getting very precise engravings and cuts.
Everything seemed good except that the laser pivoted on the X axis so I adjusted the mount with the eccentric lower wheel adjustment. I think that is when my problems started. Since then I have tried adjusting it multiple times with no positive results. That may not have been the issue. I also cleaned the lens at that time.
It looks like your rectangles are over traveling on the x-axis too and it isn’t just the text that is having a problem.
You say that it was working very precisely BEFORE you adjusted the eccentric lower wheel. I had to make a similar adjustment due to a tilt in the laser module. I posted about that in the Creality Falcon forum in the Falcon 2 Laser Head Tilt - #13 by Wet.Coast post. BTW, you might get a better response to your posts on the Falcon if you put them directly in that forum.
The problem looks like an x-axis travel issue and not something that would be related to a dirty lens. I’m guessing that you’ve confirmed that there is no wobble in the laser module at all and that you haven’t over-tightened the eccentric lower wheel nut.
You didn’t say what your settings were when you ran these tests. Have you tried a lower travel speed and power setting? I only have the 22W model and I’m wondering if with the 40W model, the temptation to use a faster travel speed is causing an issue here. Just a thought.
@Zolt, do you have any ideas on what might be going on here?
As mentionned by @Wet.Coast, the issue seems to come from the x-axis.
It really seems the carriage is loose somehow.
Here are a couple things I can suggest to check:
When you move the laser left-right by hand, do you feel something special like a jump or skipping?
The cariage itself should not move in any other way than left-right. Do you feel anything there, like you can turn it on an imaginary central pivot?
When you check under the bar on which the carriage travels, is the belt tight enough? Compare the tension with the one from the y axis.
Under that same bar, on the left, check the cogwheel that sits on the pivot coming out of the motor to ensure it’s tight enough and doesn’t turn freely - there are small hex screws to tighten it there. DON’T OVERTIGHTEN!
Oh…and that might sound really stupid, but make sure the 2 screws on the right that hold the laser on the carriage are tight - not just one of them…and again, don’t overtighten!