The belts are just a small part of the adjustment process. The wheels are much more important. Maybe some of them have worn out? Follow this guide and check all mentioned aspects: Guide to mechanical adjustments and maintenance - Diode Laser Wiki
Okay so I have figured out that when the x and y-axis roll they shift the belt over to where they rub against the the edge. Could this perhaps be the issue? These two are the x-axis belts:
It does the same thing when moving up or down on the right hand y-axis belt. Although it does not do it on the left hand y-axis
I really don’t think it’s the belts. If there was something mechanically wrong, these edges wouldn’t be as good as the are.
I have a feeling that it could be the quality of the photo. Try doing a photo that you did earlier with good results and compare the two and see if there is a difference.
Eccentric nut is too tight,wheels look destroyed and the belt is too loose
Thanks for the reply! So I got that image off of google and this is the actually picture on digital
But for a previous engraving that I have done that was good. You know there is one of a cat I did that I thought looked good but actually does the same thing. And I did a power/speed test and it also does the same I guess I have never noticed. My goal is just for it to look realistic, clean, and smooth.
The picture above isn’t bad though the material makes it actually look worse.
The picture below I did a couple weeks ago and the one on the bottom was before adjusting my belts and the one on the top is after so I agree with you on it probably not being an issue with the belts.
I believe the wheels appear destroyed because they are dirty so I will make sure to clean them. For the eccentric nut I still don’t have a great idea on how to fix that because I saw an article on it and don’t really know where it is or how to loosen it. And for the belts I assume you mean both axises or maybe just the x but I can never find a sweet spot when tightening and adjusting
i don’t see any eccentric nut. You haven’t.
this is an eccentric nut and i see only spacers in your photos.
First be sure that wheels are well cleaned of all axis, then we can go on.
The wheels are cleaned and I found the eccentric nut under next to the bottom wheels it seems difficult to adjust upright, do I need to flip the machine over in order to loosen?
So I did an engraving to compare to previous engravings and here it is:
The first one is on a material with circles on it so that’s why it look kinda weird but you can notice it doesn’t have that distinct pattern that the second one has which I just did after tightening the belts and cleaning the wheels. By the way they are both grayscale engravings.
well, i think is a mechanical issue, you have cleaned wheels but, are you sure that those wheels are not ruined by use? Consider changing them.
It’s all in the link I posted above. Step by step.
If you can move the gantry, lift it a bit or tilt it, then you need to adjust the eccentric nut.
If it feels like there is no play, then it is mechanically good.
The wheels are not worn, this is how Sculpfun supplies them.
As far as the photo goes, it is not a very good quality.
The higher the quality, the better it will be.
I hope not…
Could be electrical noise in the system. Be interesting to print an all black square and monitor the signal with a scope. Based on the pattern and the speed of the head you could estimate the frequency.
This problem is recurring theme. Here is the one where collective of this forum tried to help.
At the end user chose to swap the laser with different model and problem went away. (To me it does not mean that problem is with the laser, rather laser is not a good match to specific controller and its settings.)
Myers, I suggest you carefully read whole linked above thread and try to correlate with what you see and done so far. Note first calibration grid where slower speed have almost no noticeable Moire. It become worse with increased speed.
I’m absolutely certain that this is the same problem. The way moire overlayed and followed side edges - this is the exact same problem.
There was a few more threads of the same/similar issue (where I did not post any comments).
I guess it would be beneficial to all to finally understand root cause of this.
First of all: what are you burning? Appeared to me white paint over MDF.
Have you ever seeing burns from your machine that looks good, meaning without Moire?
My main bet is PWM frequency is too low. That is $33 settings. As lasers getting faster and more powerful - manufacturers trying to increase PWM frequency to increase bandwidth, that is time constant of laser power control filter and resulting delay/latency.
How this happened? I think I have observed pattern (of behavior) here (on this forum) where users somehow blow original settings. That can be unsupported by LightBurn variable type of some controllers (i.e. $22 in GRBLHAL is scalar, not a boolean as LightBurn thinks), or maybe some other variables as well. Maybe user unknowingly applied some other settings.
Before trying anything, can I ask you to save your most problematic work as g-code and post it here. I would like to try to see if there is any chance that Moire is in the g-code. It is unlikely, but to leave no stone unturned - worth trying.
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My first suggestion would be to play with $33 setting, that on some controllers is PWM frequency. Read it first. Then increase, maybe in 1KHz steps and see the results. It is a probability that controller support only discreet set of valid values. Try 5000, 8000, 10000, 20000, 50000 and 100000. Old GRBL default is 1000 (1KHz), many new controllers now are 5000 (5KHz) default.
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It might be impossible to apply these settings with LightBurn (variable type conflict). Try reset to defaults. Issue command in terminal “$RST=*” (remove quotes). Here is more about GRBL settings reset. you may want to save all settings first, just in case.
3.Try to disable “dot width correction”, see here. This is very speculative, but would be nice to see the effect.
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Have you run power/speed grid? Anything interesting to note?
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You definitely have severe interlacing problem (usually indication of slow laser. Hmm). Try to disable bidirectional burning, do only unidirectional.
Myers, I like to specifically ask you to not disappear, to try above and report the results and any other discoveries. I believe there is definitely public benefit to finally resolve this problem as it started to occur more frequently.
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Okay I will make sure to try everything you said soon. I really appreciate your efforts to help me and everyone on this forum. I will let you guys know how it goes and if I finally get a successful burn.
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Myers, any progress?
I am so sorry for not responding and I have not been able to try this for a while and really am sorry. I am lost as to where I edit the PWM frequency. I am on laserGRBL software(my light burn trial expired) and can’t find it.
Myers,
Bullet 1 in message 18 above. Some controllers allow to change PWM frequency by changing variable $33.
I suggest once again to go through all those bullets.
There was some claims that Moire like yours existed in LightBurn but not in LaserGRBL, but it was never substantiated. So, try to replicate it with LaserGRBL, and if successful - all these troubleshooting steps are the same , no matter what software you are running.
Okay will try and update. Thanks