Hi, 

I use the F1 Ultra laser every day to engrave stainless steel dog tags.
I always use the same settings to get a perfect result (saved settings, 50% power, speed 100mm.s, 200 lines per cm, ...). The result was always perfect and equal.

Then the problems started. With the same settings, the engraving was much lighter. I normally saw sparks when engraving the tag, but when the problem occurred, I no longer saw any sparks. And the engraving was ultimately barely visible. I had to increase the power to 75% to get a suitable result again.
Often, after a few minutes, I realized that the 75% power setting was too powerful, and I returned to the 50% setting (which worked well again).

But now I have to increase the power to 100% to have a nice engraving (with the same speed and all other parameters identical)... And I realize that the engraving is not so nice anymore. I have lines appearing. I did a test on a larger surface, and we can clearly see the lines. Have you ever had this problem?

Thanks!