Power % Question (K40, Cohesion3D)

I have a K40 with a Cohesion3D, and I’ve determined that the power setting on the control panel should be 55% in order to have 15-16 mA running through the tube. For this reason I keep the control panel on the machine set to 55%. Note that the tube will not fire at all if the control panel is set below 9%.

Let’s say I have a project that requires both an etch and a cut, so I set Max Power for the etch to 10% and Max Power for the cut to 100%. When I’m etching, am I correct that the tube is firing at 55% but the software is modulating a signal (PWM?) in order to get a 10% cycle time?

– Steve G.

I don’t think that LB does anything other than send a requested power to the controller. The controller is what adjust the PWM. From what you describe, you need to keep the LB power settings between 9% and 55%. I’m not sure if there’s a power scale factor in LB so that you can tell it that 100% in LB equals 55% to the controller and 1% = 9%, would be a nice feature. But LB does not twiddle the PWM itself .

I don’t have the Cohesion controller, but this would be the experience I have with Ruida and Puhan.

Thanks for the response. You’re right, of course: LB doesn’t have control over the hardware, and I hadn’t been thinking of things the right way. I appreciate the correction/clarification.

For whatever it’s worth, I’ve been able to set Max Power to 1% and have the laser fire (I’m using 1% on some Scratchboard).


I’ll have to look and see if there is a way for me to use 1% to actually fire.

For me, if the laser if firing from off, it takes about 14% to get started. If the laser is already firing, it will go down to about 9%, maybe less. I think there might be settings for this too ( an extra kick to get going )

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