Camera Alignment Help Please!

Hey guys,

I need some help with camera alignment on a Thunder Laser Aurora 8 equipped with the stock 5MP camera.

We manufacture medals, and a crucial part of the process involves deep engraving a circular area on the medal with the laser. Unfortunately, despite performing camera alignment multiple times, we’re consistently experiencing misalignment by 0.010-0.020 inches, which is unacceptable for our work.

The camera image quality itself is also quite poor.

Given these issues, I’d like to inquire about the potential benefits of upgrading the camera. Would a higher quality camera potentially improve alignment accuracy?

Any advice or recommendations you can offer on achieving precise camera alignment for our specific application would be greatly appreciated.

Thank you!


Is using the camera a requirement?

Could you use a fixture to position the medal at a known absolute position on the platform, then run the job?

If not, why not?

Since each medal is hand-sawed, there are slight variations in size and shape. This means even with a jig, the placement of the design on the medal wouldn’t be perfectly consistent across all pieces.

I find it difficult to reconcile those two characteristics; a picture would be very helpful.

Previous discussions around here pretty well established the best you can do with a camera is on the order of a few tenths of a millimeter, no better than 0.01 inch, on a consistent basis. If that’s the maximum deviation allowed for your work, a camera cannot bring you to your happy place.


  • There’s a pre-existing circle on the medal
  • And the laser has an accurate red-dot pointer

Then the Circle Center Finder tool can align the pattern to the circle pretty nearly dead on. The final accuracy will depend on your ability to locate the dot on the circle, which is basically what you’d be doing with a camera, with the benefit of eliminating the entire camera alignment and image correction jank.

If the circle isn’t a pre-existing mark, then I gotta see a picture to understand why being off by ten mils on a hand-sawn slab is such a big deal. :grin:

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I’ve attached an image of the part I’m engraving.

That is exactly the problem solved by the Circle Center Finder tool.

The questions, now that we know what’s going on:

  • Is the center finder is available for galvo lasers?
  • What to use as a locating dot similar to the red-dot pointer on gantry lasers

@JohnJohn should know the answers …

Does the Rubber Band Frame work on the galvo? If so, could you add a framing-only circle matching the outer ring to the layout, then center the badge in that glowing ring?

It doesn’t look like the center finder option is available for Galvo lasers. It’s very difficult to see the glowing ring, especially when aligning parts that are circular.

It’s incredibly valuable to know that this is happening consistently. The causes of inconsistent or random errors are much harder to surface.

Camera Alignment has several requirements that must be met to generate consistent results.

  • Camera must be fixed focus and fixed zoom.

  • Consistent distance from the camera to the surface you’re engraving for each camera alignment.

  • Camera Alignment performed at the same distance from the camera (elevation) as the surface you’re engraving.

and the ‘Nice to have’…

  • The closer to ‘Directly above the center of the surface you’re engraving’ the camera is, the lower the error generated by the alignment when the elevation changes.

First round of troubleshooting questions:

  • Is the error, usually predictable and in the same direction each time?
  • Is the error, larger with taller projects?
  • Where in the enclosure is the Camera mounted?
  • Is the camera mount fixed or does it move with the laser hardware?
  • How is the focus of the laser adjusted on this galvo laser?

When the camera software was originally designed for the CO2 lasers, it was reasonable to mount the camera on the ceiling (inside the lid) of the enclosure, because the bed moves to adjust the focus of the laser. This allows the target to be placed on the bed in a repeatable way, and the top surface of the workpiece stays in position and in Focus, but the bed appears to move toward the camera as the bed is lowered.

The most accurate jigs have a top surface at the same elevation as the workpiece while engraving. This serves to eliminate ambiguity when placing projects into the jig.

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