Red dot is few centimeters away from the laser head on y axis

Hi! I have an Omtech 100w with 700x500 working space, the exact model is Omtech 750 Max. I bought it in May this year and until recently it worked perfectly. I haven’t used it a lot, just like maybe 10 days per month and 2 hours per day, during this time.

I am a total newbie and I got this issue: I perform focus (it has autofocus) on the ruida controller and press enter button before every job. After that I frame design from the lightburn software and I see where the frames of my design are. I don’t own a camera so I run from the computer to where the laser is positioned to see the framing. Usually, the framing is good, the laser head frames what I have in lightburn, but when it starts to cut, it gets out of the frames I set and it cuts throughout the design on the y upper side. This happens only on y axis, on x everything is good. Also, I’ve noticed that, after focusing and pressing enter on ruida controller, my red point is few centimeters away from the laser head (going on y axis lower side), it doesn’t go exactly under the laser head. This issue happens when the design is large and covers the entire working space. On smaller design the problem is not noticeable because probably it has enough space to cut without going outside of the material on the y upper side.
I also noticed that my engraving is a little blurred compared to previous situation when the red dot was positioned exactly under the laser head.
I never cleaned the mirrors or the lens, I am planning to do so soon, but I really doubt this is a mirror or lens issue, to me it looks like a lightburn-ruida controller issue. They don’t seem to recognize the same working space and probably the focus on ruida is damaged somehow. Can you, please, help me? I will also add photos soon. Thanks a lot!

If your talking about the laser positioning system
For the Red Point issue. You need to calibrate the machine to tell it how far the red point is from the actual laser beam. I found the easiest way to do this is

  1. Set the laser beam to a low power just enough to see it.
  2. Hit the fire button and measure the distance from the red dot beam to the laser spot on the x and Y axis.
  3. Enter the information into the Laser Offset Fields and enable it.
  4. That should get you pretty close
  5. Draw a box and use the red dot to position a frame.
  6. Engrave the box and see how close it is to the frame position
  7. Do this a couple of times till you get the correct offset settings

If this isnt what your talking about try Edit> Machine Settings> Calibrate Axis

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Is cthis your red dot system?


If so, it’s about the most useless thing there is. It can be moved out of position very easily and must be constantly realigned with your laser’s position. Because it’s pointing at an angle, if your focus distance changes at all, the pointer is no longer in the correct position.

Basically, you need to always check and realign the position of this pointer before every job, or at least every day.

I removed mine and went with an inline pointer with a beam combiner. Not a small task.

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I also went from the pointless pointer to an inline beam-combined pointer, but before that my concept was to have a pair of red line pointers mounted to the laser head.

If you mount two red line pointers on the head such that each bisects the nozzle and hits the actual target point on the stock, you’re actually defining two intersecting planes that will always cross on the nozzle/target point axis regardless of focal length, etc.

It may take a bit more work for the initial setup than a combined-beam pointer, but you end up with a crosshairs pointer of equivalent utility. Also, you can add even a little bonus utility by aligning the lines with your axes. Then you can use the individual lines for corner finding and stock alignment.

The single dot from an angled off-axis pointer is nigh worthless if you use a collection of disparate lenses. I’d have to reset it every time I swap lens tube setups (and I regularly use at least a cutting-optimized lens setup and an engraving-optimized setup on the same job).

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Thank you very much for this reply. Yes, I just realized today that I have exactly the kind of red dot you are showing in the picture and it is pretty useless. The way I have to move it to position it on the pulse beam, omg. I will really have to change it asap. Thank you very much for your time!

Thank you very much for taking time to reply! I will look into this and search more videos on YouTube about it. It seems like something that I really need to learn about my laser machine. I will also learn how to perform axis calibration and ramp test. Thank you and have a nice day!

Thank you very much for your time! I will look into this matter and pick a better solution for the red point. It is clear that my current red point is not very performant and the way I need to align it to the nozzle and the beam is not exactly what I want to do before every job or even once in a while.
Thank you very much! I wish you good luck in your activity! Have a nice day!

I had the same issue with my red dot pointer. It seems the loop for the pointer is much larger than the pointer body. I removed the pointer from the mount and put 2 layers of shrink tube. It had to be pressed in but it has never moved again.

There was another thing I had to do. I had to file down the sides of the Pivot Point of the mount. So that it would allow it to clamp tighter on the lens tube. It took several tries to get it right.

I used my Bambu Labs P1S to 3D print this and I have been very happy with it. I may be an outlier because I do use my pointer quite a bit, and this 3D part makes it pretty easy to align the pointer.