Laser engraving on a small area

I have a project to engrave wood key tags and I think I might have an issue. The tags are small, 3.17x5.5cm, and already have the ring attached. The attached ring isn’t an issue as the ring will lay flat and the hook will lay in the grooves of the bed. My issue is the calibration. The unit wants to always print the focal point lines (don’t get me started on how much this wastes in materials) but prints them on the x axis and the tags must lay so the 55mm part is in the Y axis. Is there any way to skip this adjustment as I can manually calculate the focal length or will I need to manually plane down a board to the same thickness?

Its a while since I last used the laser, but I seem to remember that you do not need to run the focus every time you run a job. I certainly did the focus only after toolhead change, and never touched it again before another tool change. I entered the material thickness manually, and it always was a success. So here’s my procedure:

  1. Right after toolhead change, run a focus via calibration line pattern with a bit of scrapwood of known/measured thickness. Also used cardboard sometimes.
  2. Start the laser job - choose auto focus mode and enter material thickness after measuring it
  3. Pick work origin, run boundry
  4. Run the job
  5. Start over at 2. for the next job

Btw.: I never found that the focus needs to be too precise - the laser usually is powerful enough to do its job even with focus a bit off. Meaning perhaps +/- 0.5 mm or so… never measured it.

Something that is a bit annoying for me is the new 10 W method to measure material thickness. In principle I find it ultra cool! Thats so easy and close to perfect! Only thing not so good: It must happen in the center of the work area - I once had an L-shaped thing to cut, and there was no material at the center! Would have liked to pick the place of the measurement, but hey, you can still do manual, so not too much of an issue.