Neje 2s max never fully turns off laser

[Map (Michael)]

Hi

I am having an issue where my laser machine doesn’t fully turn off while powered up. the laser is always firing at a very low output.

the issue have always been there but I used to tolerated it. now I recently upgraded to a more powerful laser module so this issue have become more troublesome as this module is powerful enough to scorch things at this low output.

i measured to pwm signal and i can see it never goes off (1khz with 3% dutycycle).

Now my question is: Is there some machine setting that can fix this ?

[gilaraujo (Gil Araújo)]

Make sure you have a defaults firmware
Type $RST=* in console to reset it

Once done, still having the same issue?
If so you might have a issue in wiring that is allowing some residual voltage to drip into the PWM line.

[Map (Michael)]

Measuring the pwm at the connector on MB, with wire for laser unplugged. The signal is still there.

Machine is reset and updated to latest firmware.

looking at the signal it looks like the PWM when at “Zero” doesn’t turn off but makes a short pulse.

I know if you set an arduino to output pwm and set dutycycle to zero instead of deactivating the pin the output acts the same way. like in this video https://www.youtube.com/watch?v=B_Ysdv1xRbA
And I am suspecting this is the same issue.

[Dskall (D Kallenberger)]

What is $31 set at ?

[Map (Michael)]

Hi

$31 is 0

[Dskall (D Kallenberger)]

Disable fire button and see if that changes anything.

[Map (Michael)]

No change.

[gilaraujo (Gil Araújo)]

I would get in touch with the manufacturere
Expand the osciloscope timeframe so you can see the pulse better
thats not necessarly normal so you might have a bad MCU

[Map (Michael)]

Update
I am told by neje support Neje has a paramter called $40 which is used for focusing.
https://wiki.neje99.com/en/neje-3-4/manual/grbl-config

Only issue is it doesn’t show up when i try read machine settings and trying to overwrite via console just gives an error.

Second update
https://neje99.com/faq/how-to-set-focus-light.html
and here is the answer
for neje 2 it can only be done through neje software

[gilaraujo (Gil Araújo)]

@Map

I am told by neje support Neje has a paramter called $40 which is used for focusing.

if this is right, when you $RST=* you should get defaults
Seems your $40=0.01 would imply 1% would be the default on position

You can alwasy try in console to type it
$40=0.01
press enter
Restart machine and check

[Map (Michael)]

For the neje 2/2s max it only works through the neje laser software apparently its a limitation of the firmware where as 3 and up can be done via console as you describe.