I wanted to make expansion parts that were simple and fully integrated into the Thinkfun scheme but was still impressive. So I thought of something that would be awesome and then designed the parts I needed to make it. The result is this mechanical arm. the kit includes:
angled gears: These can be used to change the orientation of rotational energy.
Bent Plate: this is good for mounting things to the face of a box or other object.
Thread loop: This is meant for threading string/cabling through to manage it or transfer force over a non-linear distance.
3 way Plate: This I designed to make sturdier hinges.
3 plate: This is just a 3 hole connector, it might exist elsewhere but I couldn't find it.
Finger: This is the one part that is specialized, it is used to make the claw gripper for my arm.