The PrintRBot is a cool printer that you can either assemble yourself or get an assembled kit.  The machine uses the PrintRBoard which has been a part of the Rep Rap project for some time.  The details are located here on the Rep Rap wiki:  http://reprap.org/wiki/Printrboard

Just like the other upgrade implementations, the easiest way to upgrade the PrintRBot is to use the fan output from the control board.  This way, the firmware is already done and you are ready to go.  Simply attach new molex connector with wires (either found here in the shop or make your own) to the laser driver input.  Just make sure to connect the wires to the correct side on the laser driver.  Or to be super cool, put a SPDT switch on the positive side of the fan output and connect it to both the fan and the laser driver.  Connect the ground and you are good to go.  Easily switch between 3D printing and the laser with a flick of the switch!

Electrical connection

Here is the graphical version of the instructions:

 Mechanical:

As for mounting, we put ours on the side of the printer towards the front just right of the extruder.   The dimensions and solid models are located in the documents section of the website so you can check it out before you buy.  We suggest drilling the holes with the printout of the mount (or the lase mount itself) to make sure your holes are correct.  Just hold it up to the side and mark it with a marker through the holes.  Drill and then install.  This shows the fan mount as well attached to the top of the laser.  This allows the metal frame to help with heat sinking and have a fan at the same time.

Software:

You shouldn’t need to change anything with the marlin firmware that ships on the motherboard of the printer.  Use the following commands in our inkscape pluggin (or whatever G Code SW you want):

• M106 Sxxx   – Turn the laser ON at power XXX, where XXX is a number between 0 and 255.
• M106 S0 – Turn the laser OFF
• M107 – Another way to turn the laser OFF

Examples:

M106 S127   (Turns on the laser at a power of 50%)
M106 S255  (Turns on the laser at a power of 100%)
M106 S25  (Turns on the laser at a power of 10%)

For running your programs, we generally like using Repetier Host software for our printer/laser control.  It has a nifty preview window and good manual control.  You can set up the offset for the laser in the EE Prom settings and move the 0,0 point by creating an offset as well.  Here is where to put your offset:

And then you can use the manual tab to control the laser to turn it down for focusing.  Use the fan slider to adjust the power and turn it on by pressing the fan.

Check out our upgraded Simple engraving a picture on wood:

Buy your laser upgrade kit now!

Remember Safety First!

We sell laser shielding to block laser radiation and reflections!

Laser Goggles are also a must!

Disclaimer

 The laser used in this project is very powerful and all safety precautions must be taken.  Use proper safety eyewear to prevent injury to eyes.  This is a project and J Tech Photonics, Inc. is not responsible or liable for any and all damage or injury caused to people or property.  The use of these instructions to make a laser cutter is under your own discretion and all safety precautions should be followed.  J Tech Photonics, Inc. is not affiliated in any way with Printrbot and they may change hardware and software at any time making these instructions invalid. (edit)