Ever time I check and read I can’t find any scale to tell me how to change mm/min to percentage (%) on my laser program the power is in % and the speed is also in %. Please let me know where I can copy or download this kind of chart. Thanks. Take care and be safe all
Percentage doesn’t make much sense as a speed… 
Well, it can, I suppose, relative to the max speed the laser is capable.
So, if it can go up to 6000 mm/min (or some mm/s value or other; I just take the max speed of my little laser), a speed of 50 % is 3000 mm/min, a speed of 10 % is 600 mm/min. And of course, you can convert back. I won’t explain you how to compute percentages and back, I suppose you already know.
Thanks, yes percentage make a lot of sense. That is the only thing that I can set for power & speed. I am using a Laser program on my iPhone. So as your saying that 10%=600mm/min, 20% would be 1200 so every 10% would adding 600mm/min and that would make 100%=6000 mm/min, correct? Thanks for the info, you have a great day I did a few engraving by guessing and some were in burnt in and others came out good. For me as a beginner I think I am doing ok. Thanks again and take care
The math is correct. 
Of course, the real speed depends on your laser, but I suppose if you manipulate only percents, the real speed doesn’t matter much, after all.
And, yes, that’s the hard reality of laser burning (or cutting): you have to do tests, with various speeds and powers, to find the sweet spot. For EVERY material you have to work with! There is no hard rule like “300 mm/min, 80 % power, 3 passes to cut 3 mm of plywood”, because:
- It depends on your laser! (10 W? 20 W? More? Diode, CO2, fiber? etc.)
- It depends on the material itself (and the provider; wood, as a live thing, is particularly variable. But might vary from an acrylic board to a similar one from different suppliers)