I installed the Cohesion 3D Mini in my laser and it is working. It was a pretty standard installation using the 3 wire PWM cable(power supply has the white connectors). What I am having a problem with is that I have to set the minimum laser power to 75 to 80% when burning a calibration file for it to even mark in the 0 to 50% range. I have 2 K40’s This particular laser has always required a higher setting to do the same thing as the other laser. I have voltmeters on both lasers. This laser would take 1.6 volts to produce 4 to 5 milliamps where the other one only requires .5 volt to produce 4 to 5 milliamps. I have had a Smoothieboard(one of Scott’s ACR kits) in this laser before and it worked.Comparing the Configurations files I don’t see any great differences in the laser power settings. Do you have any ideas of something that I can try to get this dialed in?

“Mike Mauter”



Ray Kholodovsky (Cohesion3D) January 20, 2017 16:19

Mike, you may be better off putting the pot back into play, removing the pwm cable, and running L to the - bed/ 2.5 MOSFET terminal. It’s described in a bunch of other thread comments here.

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Mike Mauter January 20, 2017 18:19

Thanks Ray, I will give that a try.


Bill Keeter January 20, 2017 18:54

+Mike Mauter FYI, i’m running the laser at 100% in Laserweb using the white PWM wire. It’s showing 10mA when firing. I think the power level in Laserweb is directly controlling your mA. Also I don’t think 100% power in Laserweb is equal to 100% power of the tube. Just me 2 cents from tests last night.

I even ran 110% power in laserweb and got 12mA.

(please note, this is only confirmed in my K40 setup. Who knows if others will get the same)


Mike Mauter January 21, 2017 02:04

Bill, are you running through the pot?. My understanding is that when the pot is included that the allowed current is a product of the laser web setting and the pot setting. I hooked mine up as Ray suggested and it seems to be working better now. I didn’t have time to check it that closely but it appears that I have greater range in grayscale.


Bill Keeter January 21, 2017 02:26

I might switch it but right now I’m running the white wire from the pcb to the power supply without the pot.


Ray Kholodovsky (Cohesion3D) January 21, 2017 02:31

Ok. I’m very open to hearing data points on this. As we’re reaching more and more machine types out there the pwm pot approach may be a pain point. Ah, fun fun.


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