This week we began modeling and 3D printing the gear that will pull the cord to open/close the blinds. 

The first iteration, in green, was based on a thingiverse project; however, the beads on the Caltech blinds are much smaller and the holes were too shallow to have any chance of applying actual force to the cable. 

The second iteration, in light blue, made the holes deeper to account for this, but not enough tolerance was added, so the beads wouldn't go very far in and would get stuck if they did. The chamfers added to the slots to ensure the string didn't get caught on corners also were too small to 3D print correctly, rendering them useless.

The third (and current) iteration, in dark blue, added more tolerance to the holes and widened the slot for the string. It also has larger chamfers on the corners. This works great so far!