Acquired a ComMarker 50w Fiber laser. Trying to figure out the settings for deep engraving copper and brass coins. Not really finding any already test grids for that power. Seen some 20/30W ones.
My guess and roll the dice testing method not working as good as on the diode and Co2 did.
I was gonna make one in LB but then overwhelmed my old aged brain.
The testing docs sent with the laser say Freq range is 45 to 170. Speed is up to 150000mm/s.
So confused on what speed settings/range to setup for. Same for Khz and power. And what about passes. Should all testing be done at one pass or different number of passes.
Yup like to over think things and make them complicated as they can be.
No fiber here, too scared of them (learning issue).
What I do know is, throw out everything you know about the diodes and CO2’s. Think of photon torpedos instead of laser beams. You hit a material with a diode/CO2 beam until it cooks, right?
But a 20w fiber can REMOVE copper from a coin. How can this be? That is because you are pulsing it with a 35KW energy pulse, rapidly. Lower frequency gives the fiber time to store up more energy. Raise the pulse frequency and you actually get less power. I wish I had saved the link @jkwilborn had posted that showed how those things actually work. I am sure it will help you visualize the available parameter change effects.
Not sure which video @MikeyH was referring to, but this is the JPT MOPA source, maybe the one he’s thinking of. I believe yours is a q-switch so you don’t have pulse duration control like a MOPA. You frequency range is also restricted from that of a MOPA type. Mine allows frequencies of 1 to 4,000kHz, yours is much more limited range.
He right about one thing, led and co2 are continuous wave (CW) and fiber are pulse machines.
Frequency controls pulses/S or pulses/mm this is based on how fast you’re scanning.
Generally we do a cleaning pass, that’s at reduced power and a higher frequency, and when you have the option a shorter q-pulse width. These are Amazon brass coins 40mm diameter. Neither has any post processing and came off the machine like this.
Focus is very critical, especially with a short lens, so be aware of how far you can be off and still get the job done. I commonly use an F254mm, which is longer than most, has a larger spot, but gives me lots of room between the galvo head and work area. I still use an interval of around 0.050mm or about 508dpi. My spot size is around 50 microns (0.050mm).
You can find and close estimate of your depth of focus (dof) using any of the on-line calculators, such as this one.
Other things you might need are a manual on your source, it will tell you where you produce the most power. Mine is around 45kHz pulse frequency.
Not sure what else I can add… sing out if you have more questions or I missed what you’re asking.
