Thanks David, that’s actually the thing I printed hehe. I have a flow meter on my air assist line for use with my mister. So I use that to dial in 20mL/min, and it cuts the 1/8 birch ply clean as a whistle with your nozzle. Also, I just drilled out the air line part to fit snug on my 1/4 OD airhose. The fit is plenty secure since it’s tied from above with an elbow fitting.
I connected the included 7-segment display/controller to my primo laser, using just the 12v, gnd, and *C lines. After some testing and probing, I determined it 1) has somewhat inconvenient ways to display temperature when used with a cnc, and 2) all of the buttons are connected to a voltage ladder.
My Neje 40W module is wired to a relay to turn 12V power on/off, and also has to pwm control connected. So the laser is powered off until I start an operation on my gcode sender (or manually turn on the spindle with gcode). I also wired my Neje 7-seg board 12V to the output of the relay so it is off while I’m not running the laser. The way that Neje board works in this config, if no buttons are pressed when powered on, it shows “off”, then hitting “*C” momentarily shows the temp in [XXC] format. Letting go of the button shows “off” again. Alternatively, if I hold down the “*C” button before starting and operation, the display cycles up quickly from 0-333 or so, then displays temperature after letting go of the button. This way, at least I can see temps throughout a cut without pressing anything, but it is not what I’d call convenient to use. Adding a circuit to handle holding the button down on bootup would work (and is not hard knowing it’s a volt divider), but that probably more complicated than just programing an Arduino board, which is already quite a bit for this lol.
Bottom line for me, at the end of a longish 8 minute cut running 100% the whole time with a garage ambient of 58F, the displayed temp maxed out at 38C. Unfortunately doing the math when my garage hits near 100F during summer, my displayed temp should be a bit over the recommended max 60C. So I will have to keep a pulse on temps as my ambient starts to climb. If the fan doesn’t kick in and save the day (it has lots of overhead based on boot up RPM), then I’ll have to see what I can do to help it along.