For this project I wanted to experiment with laser cutting gears and making them move in some kind of irregular way. The stretched out main gear produces a periodic motion. One way to expand upon this project would be to add an additional gear on the outside that only engaged with the main gear when it was ‘swinging’ and therefore only moved during part of the cycle.
Although the gears themselves work, the toy motor I used does not have enough torque to swing the gear around, and my attempt to replace it with a gear motor resulted in the untimely demise of the prototype, which has yet to be rebuilt…
To build the gears I used a site that helps with gear design ( http://woodgears.ca/gear_cutting/template.html ) and then took the design it generated into AutoCAD. I generated two gear templates, one for the straight section and one for the curved section and small gears, then cut them up and reassembled them in AutoCAD and made a laser cut pattern at the right size. Since the file created by woodgears.ca was just a .pdf, there was no way to automatically convert it to a .dwg (for laser cutting) so I needed to import it as an image into AutoCAD and then trace it as accurately as possible. In the end it only needed to be more accurate than the precision of the laser cutter anyway.