Our mechanism was built in three segments, and then put together. The base of the truss raises the extended part to the appropriate height to fit through the larger hole. The base also extends sideways in the direction of the larger hole, so the extended truss part can reach the weight at the proper angle it needs. The main triangular truss portion of the mechanism is designed to resist as much torsion and bending as possible given the dimensions of the large hole. Its other purpose is to set up the lifting portion at a good distance from the weight to get a higher lift. The lifting portion is set to reach the far side of the weight. On one end of the lifting arm is a metal loop that ensures that forces transmitted by the servo act vertically on the weight. The other end is longer, and has weights added to it to maximize the lifting power of the servo.
- U-shaped lifting arm to maximize bending resistance at low weights
- Metal loop to latch onto weight to act as a 2-force member
- Entire truss made from bent sheet metal to resist torsion and bending in expected and unexpected fashions
- Main truss segment barely fits in large hole to maximize torsion and bending resistance
- Low weight and sturdy base to support weight of structure under loading