My K40 also has the potentiometer, and the C3D varies the output power just fine, via PWM of the L connection on the power supply. I really really want to vary the power output by layer. I know that the newer lasers have a digital control panel on the front that is hooked to the cohesion with a thin ribbon cable but I do not have that option. I was curious how power was going to be affected since none of the wires that I had to hook up had anything to do with the pot but I was optimistic that the software was somehow using switching of the laser on pin to approximate a given power level but that does not seem to be the case.

I am not able to vary the laser output power using software (LightBurn) No matter what power setting I assign to a layer in the software it only cuts at the rate that is set by the know on the control panel of my laser. My laser is old enough that it has an old potentiomer on top that is used to adjust the output of the laser tube. Now I am hoping someone will know how to fix my next problem. The members here were very helpful, and instrumental in helping me figure out the correct connections.

I just got my old K40 converted to the cohesion board and LightBurn software.

K40 lightburn