Basic troubleshooting question

[Julia Bertschinger]

I am new to laser cutting. I put together a laser cutter from a kit, and now I am learning how to use it. I tried to cut a rectangle from cardboard. The short sides, moving along the y axis, cut through nicely. But the long sides, the x axis movement, are not cut through all the way. Any ideas of what I should check? Or other information I didn't provide that would help?

[Matt McCoy]

Pics and more info about your machine would help.

[Mike Null]

Julia

welcome to SMC. The kind of machine and your location would be helpful information.

[Dave Sheldrake]

Diode blu-ray by any chance? if so the beams from those are dreadful multimodes and have an equally terrible beam profile.Not unusual to find they cut better in one direction than the other (it's cause by the shape of the spot)

[Julia Bertschinger]

Hi and thank you for the welcome!
The cutter has a CO2 40w tube (Yongli), and I am in Switzerland. I'll post pictures in the next post after I figure out how to do that.

[Julia Bertschinger]

I think I figured out how to insert pictures. The first picture is the back of the cardboard. Only two lines cut through. The second picture is the front. The third is the cutter.

DSC_0007.jpgDSC_0006.jpgDSC_0008.jpg

[Bill George]

Mirror or optic alignment, and what power level are you using?

[Julia Bertschinger]

20% power.
The problem might be that the mirrors are not quite aligned?

[Bill George]

20% power.
The problem might be that the mirrors are not quite aligned?

I would at least check the mirror alignment using the masking tape method but try more power and see. 20% of 40 watts would only be 8 watts and that is assuming you have a full 40 watt tube.

[Kev Williams]

man, either your X belt or your rail bearing (or both) are wayy tight- A few months ago I replaced the X rail bearing on the GCC and it was so tight it caused a wobble like that, tho not quite that bad... After many hours it still sounds like a washboard but it's finally running itself in.

Belt being too tight can do that too, due to tooth misalignment...

Why you're not cutting equal in both directions, not a clue other than tube misalignment might be causing a banana-shaped beam...

[Dave Sheldrake]

Something is either too tight or too loose, take a closer look at the cut lines, they have a wobble in them

Can you put a piece of card in front of the tube before the first mirror and fire a quick pulse? could well be beam mode causing more power in one direction

[Julia Bertschinger]

Thank you everyone! I think the wobble that is visible is not an actual wobble, but just how it looks because it is cutting through the corrugation in the cardboard. I do not see that wobble when cutting wood, though I still see a difference in in the x cuts and y cuts. If I up the power, then it all cuts through with no power.

I did notice another little problem, which I think might be related. When cut a circle the circle was slightly "smashed" on the two sides. Instead of going around the curve on the left and right sides, it goes straight up/down a little bit. Is this related, or a completely different issue?
I still need to check my beam alignment. I also think I have the belt tensions ok, but I am not sure, since I am not experienced about how they should be. I did loosen the x belt, but that made the circle really really bad.

IMG_20180422_204140220.jpg

[Kev Williams]

flat sides on circles is indicative of some some serious slop in the drivetrain, as in a loose set screw on a belt cog causing a lot of free play as the belt changes direction...