Custom Built 80W CO2 Laser Cutter

(Caleb Chico) #1

So I’m currently building a custom 80w Laser Cutter. I posted once on the google plus page but I must say I’m liking the forum style. Definitely the right direction I’d say. Anyway, I just wanted to post further progress with the laser. My goal is to turn this laser cutter into a laser cutter / 3d printer hybrid but that’s a bit further down the line.

As of 2 days ago I finished running the cables that go to the laser head (for red dot or other peripherals) through the drag chain as well as an air line. I placed my limit switches where they belong, using NPN NO Proximity Switches, wired them in place, tested them, added the !'s to the SD card, ran it and so far it all works.

Well, it wasn’t that easy… I made a lot of mistakes along the way and hopefully, my screw ups can help you.

First of all when I bought the sensors I didn’t realize that I had purchased npn NO sensors instead of NC. If you don’t know the difference between the two I suggest you do a quick google search. As of 2 days ago I didn’t have a clue. Only learned all this through troubleshooting. So I ran all the cables, made everything semi-neat, tested the sensors with a piece of metal, the sensor turned on and off, started the machine up, turned LighBurn on, interface worked, sent the machine to the home position and it didn’t work. I checked the cables everything seemed fine, restarted it and re-tried it and the same thing happened. A little cursing here, and a little cursing there, and I realized that I had npn NO instead of npn NC sensors. So I did some reading, found out about putting the ! in the right place in the SD card, tested it and it didn’t work again. I was quite puzzled by this. So I did a little more cursing and I just walked away from it and took a break. I went back online and did some more digging and found out I actually wasn’t supplying enough power for them to operate properly. My sensors required 6-36v and I was connecting them to the LaserBoard so they were only getting 5v. I then tested feeding the positive terminal of the switch with 12v instead of 5 and I finally got it working properly.

Next step is to line up, square up, and tension the belts. I can jog the motors using lightburn right now and get the laser head to move, but when I try to start a job depending on where in the bed it is located, it grinds and loses a lot of steps but that’s another issue for another day.


You can most likely also hook up the sensors + lead to 24v (for something tiny like this I wouldn’t oppose you tapping the board’s 24v power brick + from the screw terminal in the top left corner) and they might work even better. The onboard protection should handle it.

At one point in time I had a selector for endstop voltage (either 5v or the 12/24v HighVoltageIn) but it’s such a limited use case, weighted against people frying endstop and boards by getting it wrong, that it seemed best not to implement it. You figured it out :slight_smile: - and yes, running the sensor + lead to the power supply (or the workaround to that I suggested) is the correct “solution” here.

(Caleb Chico) #3

Awesome thanks for the tip. I usually try to figure things out on my own before posting anywhere. It may take me longer but I usually learn things along the way, and I avoid asking the same question the previous 8 people have.


If only we had more like you.

(Caleb Chico) #5

Progress so far

(Caleb Chico) #6