To build this plotter you will need the Lego robotics invention system with few extra parts and a laser. It's too complex to describe with just words so look at the pictures and descriptions. High powered lasers can be purchased at Wicked lasers. If you are interested in learning about high powered lasers go to Laser forums
General description: The robot can move along two axis and turn a laser on and off. The X axis is controlled by a rack and pinion that move very slowly. The Y axis is controlled by a slow turning axle that pulls a string connected to the rack and pinion assembly. Each of the axis has a touch sensor that is pressed about every millimeter. This makes the robot very precise because it knows where it is at all times. The action used to turn the laser on and off is simple but very efficient. It slides a small part over the button on the laser. This part is constantly being pushed against the laser with rubber bands. Thus it can simply slide on and off the button without the motor having to run constantly to hold the button down. I only have a 15 milliwat laser so I have to focus it. I used a small plastic tube that is about the same diameter of the laser. At the end of the tube is a small convex lens I took out of an old gun sight. This is all attached to the end of the laser with electrical tape.
I have uploaded some files and software to view in 3D. The software will install MLcad and LDview. After you have the software installed, open LDview and it should ask what files you want to open. save all of the files I have posted to one folder and open them one at a time. The file named laser plotter is the whole assembly. I recommend looking at each part individually to build them then using the laser plotter file to see how they are put together.
Posted by Laser Community member: CaptainCrash