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

1 Like

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.

1 Like

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).

1 Like