Tag: Plotter
A plotter project
by eimink on Nov.02, 2009, under Hacks
I was having a slow sunday with a hint of hangover while I remembered that I have an old flatbed scanner stashed in my closet. After some digging I found it and immediately took it apart. Pretty simple design, with a Mitsumi stepper motor. That gave me an idea to make a x-y plotter with it. I’m still hunting for some more parts but should get some old printers this week that will donate their internals to my next creation and then it’s just fabricating and coding.
The motor, Mitsumi M35SP-7N, has 48 steps in full 360 degrees rotation and runs nicely on 5V, though it can’t run very fast. But that doesn’t matter at this point :)
Testing...
After I extracted a driver chip (ULN2003A) from the scanner’s PCB I was ready to hook it up to my Arduino and run some tests. It appears that with the scanner mechanics in place, the scanner bar achieves about 600dpi precision, which should be good enough for my needs. There is a small issue though. Since the bar is driven only from one end, there is slack in the movements of the bar – especially on the end that doesn’t have the drive belt attached. This slack is visible to eye and it will cause problems in the future when there’s weight from another driving mechanism on top of it, so I’m trying to locate a similar scanner (Mustek 1200CP) and take another driving mechanism from it for the other end of the bar.
The testing software I’m using is just a simple implementation of stepper class found in Arduino examples, MotorKnob example to be precise. For the final software, I’m planning on using slightly modified GCode interpreter from RepRap project. The modifications are due to my motor driving circuitry that differs a lot from the RepRap, which has more advanced and better driving capabilities than the setup that I have here at this time.
Stay tuned for future updates on this :)
