GRBL controlled air assist (Laser)

Does the longboard have a way to read air assist on/off via Gcode? and if yes, how do you access that signal output (to a relay, etc)? If no, then how does everyone control that for jobs that require paths with both settings? separate gcode files for air=on vs. air=off?

Hello Scot, I use an IOT relay to control my air assist and exhaust fan. It is triggered by the coolant controls on the LongBoard. Then I use M8 to turn them on and M9 to turn them off. The cool thing is that when I go from ‘laser mode’ to ‘router mode’ I unplug the air assist and plug in the router and vacuum so they are controlled with M8 and M9 instead.

You can find details about the LongBoard here. You can see how to wire the relay here. I bought the relay from here.

Then when you have the relay all setup, in gSender, in the settings->program events section you put M8 on start and resume and M9 on pause and stop. This also works with LightBurn and I don’t think I had to set anything up in LightBurn, I think the default when you activate assist is to use M8 and M9 in LightBurn. Just thought I would mention that because a lot of people use LightBurn with their lasers.

Thanks @_Michael . I was hoping The coolant connection output M8/M9. Lightburn should take care of inserting those if I have it configured right. I’ll check out the iOT options. Still playing around with it. Wouldn’t you know it… Neje put the Max4 on sale right after I got the module hooked up on my LongMill. a few $100 more and I could have had the stand-alone unit. Don’t really have the space for it at the moment but hope to make some changes this summer (either get rid of my project car taking up the other half of garage… or build a detached shop). :slight_smile:

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@_Michael , do you know what the output voltage is from the coolant terminals? I want to control a relay for an air valve (vs. the compressor itself). Valve is 24v and has its own power supply. I think it is 5v but not sure. I can measure it but if you already know… :slight_smile: . I think I can use a relay like this

I think it’s 5V but I can’t seem to find it listed in the resource pages for the LongBoard so I’m not 100% sure. The signal does originate from the Arduino and from what I can gather on that it should be 3.3 or 5V depending on the input power to the Arduino. In the LongBoard the Arduino is powered by the USB cable connected to the PC. The USB puts out is 5V + or - 5% according to what I read so I’m pretty sure 5V is the answer.

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Connected my meter to it. it’s a smidge less than 5v when M8 is sent. so I’d call it 5v. Doesn’t drop clear down to zero with M9 command. reads ~ .7v, but I assume that’s OK. Guess I’ll find out when I connect it all up :slight_smile:

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