One of the cheaper boards for building your own 3D printer is the Melzi Board. It is popular among the Prusa I3 builds that a lot of shops offer in kit form. We get a lot of requests to see if this board will work with our lasers and the answer is YES! We are going to use the same approach that we have on many of the other electronic configurations and use the FAN connection for the laser.
Details of the Melzi board are here on the RepRap website: http://reprap.org/wiki/Melzi
Let’s get started!
Hooking the Laser up
Just like the RAMPS 1.4 upgrade, the Melzi board provides nice screw terminals for the connections. You can either put the laser driver wires in the same screw terminals as the fan is connected and leave the fan, remove the fan, or use a switch to change between the two. Simply connect the laser driver connection from the picture shown below to either the laser driver screw terminal H2 or using a Molex Mini Fit Jr. connector to terminal H4. Just make sure to get the “+” and the “-” correctly!
The software is the same for all of the upgrades here. The commands to turn on and off the laser are:
LASER ON: M106
LASER OFF: M107
Using PWM to control the laser
You can have power control as well with the Melzi board using Marlin or Repetier firmware. Simply use “M106 Sxxx” command to turn on the laser where “xxx” is a number between 0 and 255. 255 is full power and 0 is off.
- M106 S255 = Turns the laser on at full power
- M106 S0 = Turns the laser off
- M106 S127 = Turns the laser on at 50% power
- M107 = Turns the laser off as well
Now that you have it all set up, there are a few ways to engrave with the laser. Here is a quick post on some of the different ways along with some tutorials on getting started.
Then simply run the file in whatever program your printer uses! Voila!