Frustration with Air Assist, please help!

I’ve got a new laser that just arrived. I’ve been working on setting it up and one of the first things I’ve done is to upgrade the air. Here is the setup for the valves:

I’ve enabled both check boxes, the one via RDWorks and then the one under Manufacturer settings as seen below.

The wiring here is that the first valve (Low Pressure air) is connected to status and the second valve (High Pressure air) is connected to Wind.

I tested the valves with a 24v bench supply after I connected the diodes and the solenoids definitely activate. I’ve also measured the 24v from the 24v line on the controller. I get no soleniod activation when I turn on the laser. Any suggestions? What did I miss?

Although opinions differ on this, I highly recommend using a DC-DC solid-state relay to protect the controller from the solenoid valves. Plenty of people don’t, but the penalty for a glitch is killing a controller output transistor worth five Benjamins, rather than ten bucks worth of SSR.

I cannot tell from the pictures: the solenoids must be connected from the +24 V supply to the controller output terminal, because the terminal goes low when it is active. You can check that with a voltmeter, although it’s awkward.

Your profile lead me to assume it’s a “K40 extended” with a “VMS LXS4 / GRBL” controller, which is obviously not the case. Add your new puppy to the list so other folks know what to expect! :grin:

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If the controller isn’t switching, then it doesn’t much matter what’s connected, it won’t work.

I suggest using the basics with a voltmeter and check across the coil of the solenoid for full voltage.

Status should go active as soon as you start executing any layer. I think this is here

I can’t run RDWorks natively, so I can’t relate to posts using that software.

If Status isn’t going active, you won’t know if the other solenoid picks or not.


On ruida controller you have under menu option for diagnostics. Open that sub menu and there you can test all end stops, cover protection, water flow protection and test all outputs. Like someone wrote before me, you have to connect negative wires from solenoid to controller outputs and positive to +24V.

He doesn’t have a problem with the inputs, home, limits, cover protection or water flow ?

It would be very enlightening if you can advise us of how to do this?


I have RDC6432g controller and it has both inputs and outputs together in diagnostics. Maybe your controllwr has two sub menues, one for inputs, other for outputs. Also If you have Rdc6445s, there are on controller board LED-s.

Can you move the cursor down there and toggle them?

I have a 6442g, as you can see from the photo, no control there…

I’m lacking that also… here’s my controller led… not output indicators, all are inputs. I have the manual for the 6445, but the photo is of a 644xg and it looks just like mine.

That’s neat you can toggle output… it would be handy…


It looks like only RDC6432g has that option. I have spare 6445 controller in box and it looks like main board is same as yours.
What I hate about 6432 is, that on controller display has +Z and -Z buttons, but on main board you have U axis for stepper controller. I can move bed up and down, but it doesn’t do homing even I selected in vendor settings on lightburn.
I’m just finishing make over of versa laser VL-300. I managed to use it’s original endstops and stepper motors, made all new connections with silicone cables,… at the moment I still need to install CO2 tube and align mirrors.

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Nice plane!

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That’s another data point in the mystery of how Ruida controllers work: the Machine settings accessible through LightBurn do not include all the configuration values required for axis homing and auto-focus.

Apparently the sellers set those values so the machine has the “as advertised” features before shipping it, leaving no way for customers to add those features after the sale.

Thanks for filling in another blank … :slightly_frowning_face:

Also there are two outputs for future upgrades, but it more looks like they will never happen.
But ok for me, since I started with K40 laser and now moving on more complex machine. I like ruida controllers, since they have live feedback on display, some nice features, but their biggest cons are lack of good documentation and costumer support.

Thank you!
That is another long story… I bought ARF from hobbyking and removed covering film, some of material and make it more scale…

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If you’re talking out1 and out2, these are currently used and the Ruida manual say they are reserved. Many people use them for stack lights.

Here’s short video of their operation… Top led down status, out1 and out2


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One option to test outputs is to use resistor and LED. Also check your power supply. Some lasers come with small 24V power supplys just for ruida controllers and end stop sensors, maybe status light… rest of it might run on 36 or 48V.

From the manual

24V (compatible with 36V for power supply, but not recommended)

Many or most of the stepper drivers can make use of much higher voltages as outputs to the motors. I’ve seen then in the 60V area.

Just ensure they’re voltages are isolated from each other. The inputs of motor drivers are usually optically coupled so voltage change or issues at the interface isn’t a worry.


I added a switch, and I can turn it on via the switch for manual override, but I still can’t get it to work automatically. I’m not sure if the power supply can handle everything connected to it. It dips a bit below 24v so that may be the issue. I haven’t tested the valves independently with less than 24v.

I can make it work for now but I’ll probably look at upgrading the power supply and/or add an additional one for the steppers by themselves

Justin, Looking at the photos you posted, I am assuming that you have the negative lead of the valves connected to the STATUS and WIND outputs of the controller.
I have read mixed reviews on connecting to the controller this way.
Some work, some don’t.
I found a video on Youtube where a guy bought switchable solenoid valves instead of the normal Pos/Neg valves like you have in the photo.

He powered the valves via the 24v and ground outputs of the controller and then connected the switching mechanism of the valve to the STATUS and WIND outputs.
Full disclosure here, I have not tried it yet.
But I did buy everything to do this particular upgrade and I plan to try it out this weekend.
If you like, I can report back if it is a success or not, and if so maybe you can buy the valves like in the video and give it a try on your end.

Here’s the video link:

You kind of lost me in your description. No idea who or why/if others had failure.

Suggest you wire it up as stated… This is from the manual — these solenoids run the work status lamp – using the out1 and out2 sinks.

It doesn’t matter if you wire it to out1 or out2, status or wind, one side to 24V then the Ruida is the sink to ground. These are standard open collector type.

This is the way they work and as far as I know, that’s how we’ve wired them up, mine is … just like the manual says…

It’s your machine, you get to do what you want :tada:


Justin, per my comment a few days ago, I can confirm that the method mentioned in the video works perfectly.
You power the valves via the 24v and ground outputs of the controller and they are activated via the WIND and STATUS outputs of the controller.

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