This is the crane project, shown here from above. The task was to design a crane that fit into a playing field without interference, maintained a certain level of rigidity while under a loading scenario, and was as light as possible. For loading, a 1 lb. weight was placed at the end of the crane, and the total deflection at the end had to be less than one inch.

We decided to go for a very minimalistic “open truss” look. This meant that while not being nearly as strong as a Warren truss, it is much lighter. We had to be very careful about bracing and supporting member placement - including precreasing some beams so that they fit the odd angles that would normally be solved with two or even three beams.

Here you can see our crane under the loading scenario of 1 lb. The total deflection was 3/4”. For the purposes of this project, if the crane deflects under 1” it is treated as a success - getting 1/4” deflection is just as good as getting 7/8”. Once we had the crane not deflecting at all, we began removing supports to get as close to the 1” limit with the lightest structure possible.

Our crane had just two arms - one that went through the window and one that went to the post. We decided to go for a singular junction point to save materials. The four beams of the major arm were bent into L shape cross sections to increase the moment of inertia. They were supported by a few cross braces and vertical braces throughout to keep their form.

In order for the members to come in at an angle and then meet flat, they were snipped. Because this is introducing a fissure, L supports were bolted to each member to hopefully regain some of the lost integrity.