Went to use my laser yesterday and noticed that the further it got away from the side mirror, it would stop engraving. It was almost like it was a printer running out of ink, no issue had this happen when I first got it, somehow my mirrors have gotten off. So I had ordered a upgraded board for it so I waited until that came in today to mess with it. New board installed, Lightburn installed and connected to the laser. Alright lets get this party started! Go back to step one with alignment, worked my way all the way back out to the laser head. Hitting the same hole, good to go! Start to cut… nothing… Placed a sticky note over the hole by the tube, fire, good. Place a sticky note in front of the X mirror, fire, good. Placed a sticky note in front of the laser head, fire, good. Placed a sticky note under the laser head on the work table, fire, nothing… jack the power up and still nothing. Turned the power up even more and finally got a arc of a line on the paper. Took the laser head apart thinking something might have gotten in there or the mirror or focus lens is dirty, nothing. Clean the mirror and the focus lens and put everything back and now I don’t get anything at the work end of the laser head. I’ve googled, looked in here in past post, because I really didn’t want to bother you guys again, alas here I am. I started working on this around 4pm today and I am now calling it quits and calling in the cavalry! As far as the new board, I followed the instructions to the letter and that is the only thing I have “changed” since this issue started. But I cant for the life of me figure out what is going on. Thanks in advance everyone.
Looking for help on this forum is NEVER a BOTHER :), helping others is one reason we are all here.
Let me summarize the problem:
The laser marks targets up to and including the laser head (mirror 3).
Under normal power, the laser does not mark anything at the table.
Under very high power the laser marks an arc at the table.
The only thing you did between working and not working was to replace the controller.
Since you are getting a beam up to mirror #3 I would not expect that your controller is not the problem. Assuming that you are using the laser test button to fire the beam that function has little to do with the controller.
Plausible causes of the problem;
The beam is not traveling perpendicular to the bed as it leaves the 3rd mirror and enters the objective lens’s housing. It’s hitting the side of the lens housing.
The 3rd mirror is misaligned and the beam is not hitting the center of the objective lens
The 3rd mirror or the objective lens is damaged
Provide additional information:
Photo of the spot as it enters mirror #3.
Photo of the spot at the surface (at high power with the arc).
Things to try [post photos]:
Put a target directly over the objective lens’s aperture and fire.
Inspect the housing again for any show of damage inside on the side walls.
Inspect the lens carefully to see if it is cracked or has any surface damage. Sometimes hard to see.
With the lens and its holder removed place a target over the heads opening and fire.
Don’t worry about having a contribution deficit. We all have our turn in the problem barrel and eventually, it evens out. Most of us are paying it forward anyway.
Photo #3: the beam does not look like it is the center of the aperture. Notice that there is a fully formed spot and more power at that point than there is at the surface with the lens installed. This suggests to me the lens is causing a problem.
Photo # 7: I have never seen a meniscus (raised-looking area in the center of the lens) like that on a lens. Is this a stock lens? Is that a mark from the lens mounting? That said it may not be a problem if the beam is exactly in the center. However, if the beam is hitting the edge of that meniscus or mark it would be a problem. The half-moon could be the part of the beam that is clear of that perturbation and get through the aperture.
If I interpreted Photo #3 correctly and since you can’t adjust mirror #3’s angle (part of why I dislike that head) adjust mirror two’s angle to see if you can move the beam into the direct center of the aperture. To see what you are doing you may be able to press the target up against the open aperture to mark (dent) it so that you can see where the beam is hitting relative to the aperture when you remove it.
You may also find something that fits over the objective cylinder as I did with a pill bottle. Tape a target to it slide it on, burn the dot and then remove it to see where it lands.
You also can try rotating mirror #3’s mount to center the beam in the aperature.
Sorry for the delay. Went back and again reset all mirrors and tried to align them again. Got all the way back to the laser head. Same end result, moved the laser head into the beams path (instead of attempting to bring the beam to the laser head) and it still would not hit the work table. I ended up having to take a drill to the bottom of the laser head (part where the air assist attaches) and drill out the hole. This has seems to have fixed the issue. Not sure why all of a sudden the laser head nozzle got out of alignment. New problem is half way through a project I get the error message in Lightburn that it has lost contact with the control board… Lightburn’s help page says that it could be the USB cable, which I do not use the one it came with, I have a Amazon brand cable. Another issue it stated it could be is a power fluctuation due to a compressor turning on dining the power to the control board. I don’t think it is this as I have upgraded to a cohesion control board and it has its own power supply separate to the power from the machine. Anyways thanks for the help again guys!
What @HalfNormal said. It still seems that your beam is going through the head at an angle vs perpendicular to the work surface. But I am glad you have it working. It not uncommon to knock mirrors out of adjustment. My guess is you beam entering the head is ramping upward/downward causing the beam to traverse the head at an angle after it is folded.
Does it do this intermittently or repeatedly with that job?
Go back to step one with alignment, worked my way all the way back out to the laser head. Hitting the same hole, good to go! Start to cut… nothing… Placed a sticky note over the hole by the tube, fire, good. Place a sticky note in front of the X mirror, fire, good. Placed a sticky note in front of the laser head, fire, good. Placed a sticky note under the laser head on the work table, fire, nothing… jack the power up and still nothing. Turned the power up even more and finally got a arc of a line on the paper. Took the laser head apart thinking something might have gotten in there or the mirror or focus lens is dirty, nothing. Clean the mirror and the focus lens and put everything back and now I don’t get anything at the work end of the laser head. I’ve googled, looked in here in past post, because I really didn’t want to bother you guys again, alas here I am. I started working on this around 4pm today and I am now calling it quits and calling in the cavalry! As far as the new board, I followed the instructions to the letter and that is the only thing I have “changed” since this issue started. But I cant for the life of me figure out what is going on. Thanks in advance everyone.
. I think I have all the pictures you have asked for.
