Power & Speed Settings

[Trey Tull]

I have been working up a good recipe for LMM-14 on some copper nickle coated parts. These parts are .6x.8 but I have been putting one in the machine (60w 18x32 ULS) at a time. Now that I have a good recipe for everything, I want to make a jig that will allow for 250 - 500 to be put in the machine at one time. I have my power at 65 and my speed at 55, so can I just increase both numbers at the same rate and keep the resolution and detail?

I can't put 250 in the machine just to run a test, so I'm hoping I can up the power to 100 and the speed to 90 and it will keep the same level of detail as running at 65p and 55s. This would allow me to cover more more parts faster.

Thoughts....

As always, thanks for the wisdom.

[Mike Null]

Trey

My two cents worth is this. I don't believe that you can follow a linear progression to successfully increase speed and power for this material. I believe if you have found the optimum settings at 65 and 55 increasing them will not change the resolution nor the detail but what I believe will change is the success you've found at bonding the chemical to the metal. For lack of a better term, what I call dwell, the time and power of the laser spot on the target, is critical to producing the desired result. Altering that will degrade the results.

Bear in mind that this is my theory and not scientific fact.

[Kev Williams]

What Mike said :) --

Cermark needs time to heat soak. Your recipe using only 65% power at the moment somewhat proves this theory. IMO you can definitely raise the power and speed, but it's going to take more experimentation to find the point of 'diminished return'. Cermark is finicky stuff, especially with a glass laser, I can't get good results using more than about 35 watts power with mine. RF lasers and Cermark get along much better. However, I only have a 30w and a 40w RF laser to compare with, and I never use less than 100% power with either of them.

But all lasers are different- with my old 25w ULS I could actually char the Cermark if running too slow. But my 40w LS900 won't char Cermark no matter how hard I try. No clue why this is... ;)

You should continue testing, raising power and speed in 2-3% increments. To test the mark, you should sand and/or scotchbrite the mark for durablilty. And with the materials you're engraving, before abrasion testing it would be a good idea to knife-test the mark; if you can pop off ANY pieces of the black to reveal bare metal (without actually digging the blade into the metal), it's not fused sufficiently and won't last.