Overview
The arm design is the most technical and difficult part of the robot. It was designed to be the only individually moving part on the robot, and so that it could function to hit the lever and extract the core. The arm’s design process and building was arguably the most difficult aspect of the robot.
Issues
Many, many ideas were thrown around for the arm after the initial development. Here they are presented in chronological order. They all share a few traits–they would all be mounted somehow on a servo motor, and they all would be at the same position on the robot.
- Claw–This was the original idea, a mounted claw on servo motors that would be designed in SolidWorks and laser printed. The idea was abandoned because the team kept overthinking it.
- Electromagnet–It would be mounted on the front of the chassis, and turned on and off from its own power source via the proteus. Again, this idea was abandoned after some research because of cost and level of difficulty.
- Permanent magnets on an axle–This was the idea that was carried through to the performance test.
Performance Test 2
The objective of PT2 was hitting the lever. A servo with a straight erector piece glued on to it that had a metal axle through the bottom rung was used. This was to be the foundation of arm (where the magnets would sit) and the finer details were to be figured out later. The team obtained full credit and bonus points on PT2.
Performance Test 3
The team’s design luck ran out for PT3. The axle on the erector piece was unbalanced, the magnets did not have a secure placement, and the robot had trouble navigating to the precise spot that the magnets needed to be at. After this complete failure, it was back to the drawing board for G6.
Moving Forward
It was decided to return to a more simplified version of the original claw design. G6 kept the foundation of the arm (the erector piece glued to the servo attachment) and screwed in several other erector pieces together to create sort of a mouth that could extract the claw and had a flat bottom that could come down and hit the lever.
As for navigation, optosensors for line following were originally attempted during the development process. However, because of unknown reasons, the optosensors purchased were not functioning, and it was decided that the time and effort it would take to figure out the issue (as it was not a wiring/circuit issue) would be unrealistic. G6 decided that in the future, navigation to the core would have to continue to be carried out by the same process of an RPS check and timing.
Here is a two sided view of the final arm.