Camera Alignment Calibration every Start of Lightburn

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1

Hello,

So I manage to purchase a webcam and manage to install it on my laser. My problem is that every time I disconnect my laptop to the machine and laser after a task (same day, around 1-2hrs interval), the alignment of the camera and the machine gets messed up(misalign). So I have to do the Calibration alignment all over again. Am I the only one who has this problem or my setup and calibration of the machine and camera is wrong?

Can someone help me.

Thanks

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2

How is your camera mounted? And do you have a Z axis on your laser?
The two main culprits of misalignment are:

  • Your camera is not mounted in a way that it is in exactly the same spot every time. This can happen if it’s on the machine lid and that doesn’t always go back to the same place when raised, or if however you have the camera mounted is some play in it and the camera can move around.
  • The top of your material is not always at the exact same same from the camera. Usually this will happen if you are moving the laser lens tube for focusing, meaning that you are changing the focal plane relative to the camera. The ideal setup for use with a camera is where the bed moves to focus the laser so that the focal point is always identical (relative to the camera). Even having the material be 1-2mm lower or higher than normal can shift the camera alignment a significant amount (depending on the size of your machine).
3

-My camera is mounted firmly on the machine lid and my machine has no z axis.

To give a better understanding on my problem, image on the overlay mis aligns after I disconnect the camera.

Here’s the before I unplugged the webcam, everything is aligned and works well.

Before

After I unplug and connect the webcam again to the computer the overlay will look something like this:

Capture
Capture866×656 120 KB

Anyone having this kind of issue?

Also I have tried saving the setting on the camera control, still the same.

sa

4

“Save Settings” on the camera control window saves only the shift, width, and height adjustments (if you’ve made changes). The camera calibration data is saved automatically.

Try this:

  • Make sure no camera is selected
  • Go to Help > Enable Debug logging
  • Select the camera
  • Capture
  • Unplug the camera
  • Plug it back in and select it again
  • Quit LightBurn

You’ll find a text file called ‘LightBurnLog.txt’ in your Documents folder. Attach it here. My suspicion is that the camera when reconnected isn’t using the same capture resolution as it is when first connected, but that should be chosen automatically. Hopefully the log will give some hints.

5

Here’s the text file.

LightBurnLog.txt (1.3 MB)

I ran with the same issue today as I update the overlay.

First update on the overlay was there was a little difference between the actual alignment of the lase.

Second update on the overlay, everything is messed up.

6

When you unplug and then reconnect the camera, are you re-selecting it from the drop-down list? (you should be)

7

Yes and I also use the same usb port since I am connected to my machine via usb also.

8

I have a similar problem, but not nearly as severe as yours. I have to do the realignment quite often. It’s only “exact” right after I do the alignment tool. If I turn everything off and unplug my laptop, the next day, it will be off some. I haven’t measured how much it’s off, or if it gradually gets worse and worse. However, a few weeks go by and it’s off by an inch or more both vertically and horizontally, so I have to realign again.

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9

The only thing that affects camera alignment in this way is physical movement of the camera relative to the top of the workpiece. That’s it - there is no other way this can happen, so somehow your camera is moving, probably a tiny amount.

It could be that the material it’s mounted to has flex, or the hinges or gas struts holding the lid are slowly loosening, or something along these lines. What it is not, and cannot be, is the camera code slowly altering the numbers on you - it just doesn’t happen. If the numbers are corrupted in some way you’ll get something like what bhembhoi posted, where the image is nearly unrecognizable, because of the way the math works.

10

Thank you for the info. I will see about the mount and make sure everything is tight and stays tight. Appreciate it!

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