Hi guys, this is my first post in here and I’m hoping that someone can help me find a solution to an issue I’m having with X axis on my CO2 laser.
When I cut or engrave a long straight line along the X axis the line is not 100% straight (it noticeable when the line is longer than 10cm long) exemple when I engrave a square or rectangle both lines that were engraved along the X axis are not straight but they look identical (a bit wavy on the same spots)
Not sure where to start with the troubleshooting?
Thanks for any help in advance.
Start with your belt tension.
Pictures will help us see what you see.
The errors are in the Y axis, because the motion is perpendicular to the X axis.
First guess: the Y axis belts are slightly loose, perhaps because the screws aren’t tightened correctly. They should be taut, but not tight like guitar strings.
Second guess: the laser head is loose, either because the screws weren’t tightened or they are “tight” in stripped-out holes. With the power on and the laser head in the middle of the platform, grab the lens tube and try to push it gently in all directions: if anything moves easily, that’s the problem.
Third guess: the focus lens inside the head may be loose and rattling around.
Thanks for the speedy interaction, much appreciated.
I’m not next to the machine but in the picture attached you can see that what supposed to be straight lines are parallel but not straight (sorry for the pic quality, it’s a failed acrylic Spotify plaque I tried)
Ok, thank you for the advise, I will do that
Those are relatively long variations and suggest something is very loose / slack in the Y axis.
Zero-th guess: check all of the setscrews in the pulleys and couplers from the Y axis motor to the gantry. Many of those will be hidden in nearly inaccessible locations inside the rear of the machine, as in my 60 W laser:
With the power turned on, you should not feel any slack or easy motion when you tug the belts by hand. You can also (try to) turn the belt drive pulleys by hand, with any motion indicating a loose fitting between that point and the motor.
Basically, try to move things that should not move to find out where the slack comes from.
Ok I will check it tomorrow, thanks.
What I don’t understand is how y axis belts can cause the line that is engraved along the X axis to not be straight, when I engrave a straight line along the X axis I get the same wavy path every 10cm more or less but from my understanding when engraving a straight line along the X axis the y axis belt are not moving
Yes correct… that indicates it is moving when you don’t want it to…
Have you checked belts… @ednisley advise is sound…
No I haven’t yet, I will check the belts Sunday when I’m next to the machine. I will do what @ednisley suggested by moving the belts manually, just to be sure, if I notice that laser head is moving without applying any resistance it means that the belts are loose right?
It’s a relatively simple drive system… Where exactly it’s got a problem can be difficult to say, remotely…
You’ll have to use your tactical skills to feel how it works… Unfortunately, there is no real guidelines except experience.
These can also be too tight, so make small adjustments…
Good luck
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The laser head is moving along the X axis, but the Y axis should prevent it from moving in a perpendicular direction. You see that motion as a wobble in the line.
Because something is not tight, the laser beam moves enough to cause the wobbles. My guesses started with the Y axis machinery, because the fault is probably somewhere in there and the hardware is relatively easy to check.
Remember that you are trying to find a very small amount of motion, not anything obvious. The hardware should put up a stiff resistance to being pulled around with absolutely no free motion.
When you check the screws, any looseness you find will cause a problem.
Another possibility: the laser head rides on a linear rail across the gantry and the screws (on my laser’s rail) are 6 cm apart.
Make sure all those screws are firmly tightened into the gantry and no dirt / debris / dust has gotten packed between the rail and the gantry.
Again, you’re dealing with a very small motion, so slightly loose screws can cause the problem.
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Thanks @ednisley, tomorrow I will check the screws and belts, hope that will solve the issue , most of the project I was working on didn’t require millimetric precision that’s why I didn’t bother that much, now that I working on the Spotify plaques that small motion is affecting the final result.
Cheers
I managed to resolve the issue, It was a loose screw of the laser head holder that was causing the off motion, I adjusted it and marked the position of all the screws so if one got loose I can tighten it to the same position without having to go through the adjustment process.
Thank you all for the support, I really appreciate it.
Happy new year
That’s valuable information!
Although the usual suspects are belts and pulleys, it seems the screws in the laser head on CO₂ lasers either work loose or were never installed correctly.
Thanks for reporting the solution!
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