Saturday, November 22, 2008

Robotic arm drawing machine

For our mid-term project in Physical Computing, Jim Lamiell, Kristen Loeb and I created a drawing machine using two servo motors and a little bit of inverse kinematics. We set out to draw a straight line using with a contraption in mind that would mimic a simplified human arm.

The first servo acts like the shoulder and is connected to an arm with another servo at the end that acts like an elbow. The second servo has is connected to another arm with a marker on the end that acts like the hand.

The trick is to tell the servos what angle to go to based on the position of the marker(mouse). This can be done using the law of cosines and inverse kinematics.

We were able to make it draw, but not a straight line. I remade the arms using a CAD program to make it much more precise. I will post another video when it is finished.

PComp Midterm: Drawing Machine from James Lamiell on Vimeo.


  1. Very cool stuff, Matt :)

    Are the lines a little sloppy because the parts used were not precise? Or was it that his hand was not as precise?

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