Design Developement

As can be seen from the solidworks drawing we have decided to make alterations to our chosen design.

We changed the structure of the arm so it is now constructed from four sections of box section instead of two. This is because the arm must carry a minimum of a 1kg load and it needs to be able to withstand the forces applied.

Initially we placed the motor for the elbow joint on the opposite side of the shoulder pivot to act as a counter-weight. We decided that the 0.1kg mass of the motor was negligible compared to the 1kg applied load. It is also important that the moment of inertia is as close to the shoulder pivot as possible to maximise it's speed and agility. Taking this into consideration we moved the motor on the other side of the pivot and closer to the elbow joint. This simplified the design and reduced the size of the belt, minimising the chance of it inducing errors into the system.