With the laser logic board done and the wires labeled, “all” we need to do is wire things up to the Arduino control board. Most of this is relatively easy, just take your time. UNPLUG YOUR LASER FROM THE WALL BEFORE GOING ANY FURTHER!!!
1) Place the 2.54mm Jumpers on the Stepper Shield and Mount the Stepper Drivers
Under where the stepper drivers go are three pairs of pins. These are the microstepping mode selection jumpers. In a nutshell, if you leave all of these populated, you’ll get a lot of torque on the stepper motors but not great resolution. The end result is some fairly choppy and loud movement that results in jittery cuts and engravings. To fix this, populate all of the jumper pairs with the jumpers. Technically speaking, you only need to populate the X and Y sets, but I personally populate all of them if only to have extras leftover if I need them later.
Add the stepper drivers onto the motor shield. Make sure you line up the Enable/EN pins, otherwise you’ll blow the motor drivers. It wouldn’t necessarily be a bad idea to only mount two at a time (one for X, the other Y) and save the others for a rainy day. If your steppers came with heatsinks, install those as well.
2) Solder in the Laser Logic Board
If you haven’t done so already, solder the three wires to the laser logic board. These would be PWM, LASER_ON, and GND.
The PWM wire gets soldered from the logic board to pin 11 (D11) on the Arduino. I’d recommend soldering this to the stepper shield.
The LASER_ON wire should be connected to the laser control wire you found earlier. Use a bit of electrical tape or heat shrink to protect the connection.
The GND wire can hang free for now. It will eventually go into the GND/0V screw terminal of the stepper shield.
3) Wire in the Stepper Power
The stepper motors take a fair amount of power to move cleanly. Strip the end off the 24V wire from the laser power supply and screw it into the positive/+/Vcc pin of the stepper motor shield. Do the same for the 0V wire on the laser power supply into the 0V/GND terminal, but this time also place the 0V wire from the laser logic board into the 0V/GND terminal as well.
4) Add the Stepper Motors
Fit the X and Y stepper motor connectors into their respective places on the stepper shield. You may need to bend the male headers slightly one way or the other to get these to fit on well. Don’t worry about which direction these go quite yet, just make sure the wire colors are in the same direction for both connectors.
Place the stepper shield onto the Arduino and place the Arduino on a non-conductive surface (like a piece of wood or tile). Double check any of your connections and then close any open doors and plug in the laser. Disconnect any USB connections, turn on the power switch, and wait a few seconds. Listen to make sure there aren’t any pops or miniature explosions. If all seems well, power down the machine and take a quick look at your circuits for anything burned or damaged. If this goes well, you are ready to connect the system to your computer.