Co2 Laser: Power % to ma confusion

[darkened123]

Hey guys,
I'm setting up a laser cutter and am having a bit of an issue getting the power to behave itself.
My tube manufacture states that the operating current should be around 18ma but i have been unable to achieve anything above 5ma.

Ive tried varying the power % of my cuts in lasercad and on the controller itself with the "laser" button but have been unable to achieve a current of above 5ma.

My tube is spec is:
Specification 40W
Wavelength 10600nm
Power output(W)： 40
Triggering voltage(KV) 22
Operating voltage(KV)： 15
Operating current(mA)： 18
Outer diameter(mm): 50
Length（mm）： 700

Im using the '2012 AWC608 DSP Controller' with pololu stepper drivers and mirrors and focal lens from this kit.

Ive tried varying the PWM Frequency under manufacture settings between 15-25K but this didnt seem to have any noticeable effect.

When I press the manual test button on the laser power supply the current hits somewhere above 10ma but I have been unable to achieve current levels like that from the controller.

Test cuts were done with PPI turned off.
All the limits and steppers are behaving themselves nicely.
The tube is basically new, having been used only for calibration cuts and the like.

Anyone have any thoughts or advice?

[twosoc]

hi, it might be something and nothing , but have you checked that the max power setting on the manufacturer page has been set to around 60-70% ?

If its a lower number it might be limiting the output to the tube.

[darkened123]

Hey twosoc,
Thanks for taking the time to reply.

The max power is currently set to 82%.
Ive attached a screenshot of the manufactures parameters screen in case you can see something I might of missed.

[twosoc]

did you remember to save to the dsp? A few times I tried altering different bits to no avail then I realised that I hadn't downloaded it to the unit, so it was staying on the original specs.

the laser test fires at about 10ma on mine too, I think its the default setting, I'd love to be able to trun it down but haven't found a way of doing it, it would make alignment a lot easier if it didn't burn through the masking tape straight away

another thing to check is that you have the power supply set to the right voltage. Whereabouts are you, are you running on 110 or 240v?

[waltfl]

try to set the TTL to high level effective
greetings
waltfl

Hey twosoc,
Thanks for taking the time to reply.

The max power is currently set to 82%.
Ive attached a screenshot of the manufactures parameters screen in case you can see something I might of missed.