Diag. 5.14, Taken from Preparing for the Game Drop

This robot mounts the overbumper intake and a flywheel onto an extendable arm. The extendable arm is the base for this robot's shooting mechanisms (instead of the drivebase, as is typical) because the extendable arm structure both creates the arm that the overbumper intake requires and allows for the flywheel to shoot at a variety of angles.

Diag. 5.15, Taken from Preparing for the Game Drop

This flexibility allows the robot to shoot into the amp from a range of locations, as well as allows for the flywheel to tilt downward just enough to also score in the amp. When this motion is used in conjunction with the low hook of the climber, the robot is also able to score into the trap. 

The climber utilizes 2 telescoping lifts, with 2 static claws on each lift. The hook on one side is near the top of the lift to facilitate a quick grab onto the Stage's chain. While the hook on the other side is the low hook that allows for the robot to score in the trap. 

Robot Design Learnings

This robot was a culmination of what 4817 had learned over a 4 year period and resulted in one of the best robot in the team's history. The matches for this robot can be found here and here by searching for Team 4817.

What Worked Well

This robot in general was well integrated across mechanisms. This was done by dividing the CAD work at very clear boundaries, with one designer making the extendable arm, a second designer focused on the intake and flywheel, and the remaining designer responsible for the drivebase and lift. The careful planning, constant communication, and experience of members allowed for the design to be CADed with few revisions. 

The robot throughout the competition was able to score into the Amp every match and could shoot into the Speaker relatively consistently. The robot could also aim into the Speaker automatically by utilizing a combination of the robot's cameras and the field's April Tags. 

By putting the intake and flywheel on an extendable arm, the flywheel could be quickly retracted and never took a hit throughout all of the matches the robot played in. 

The robot could achieve a very fast climb with the hooks on the high side. This climber also allowed the team to climb with a partner on the same set of chain, allowing for the alliance to score additional points during the endgame.

While more of a feat of the electrical and programming of the robot, rather than the design, something noteworthy was the robot's usage of April Tag tracking and directional lights. This robot had LED strip lights on the perimeter of the robot, 3 cameras, and an Orange Pi. These cameras would use the ID tags on the field to determine the position and orientation of the robot. To ensure the perfect positioning for the team's autonomous programs, the LED lights would flash in various ways to tell the drivers how to move and orientate the robot until it was in the correct position for the beginning of a match. 

What Could Be Improved

While it was possible to position the arm so that the intake would be fully within the robot's frame perimeter (in order to fully protect it), it was determined to not be practical to do so, as the arm had to rotate quite a bit to do this. Rotating the arm would lead to a significant elevation of the robot's center of gravity making it more unbalanced, and it took more time than expected to maneuver the arm in such a way. The arm generally wanted to stay low to the ground to facilitate picking up Notes, and shooting into the Speaker from really close up. It was fastest to just fully retract the lift, while rotating the arm the minimum angle possible. This resulted in the retracted position of the arm, (as the robot moved about), being the left position shown in Diagram 15.5. Due to this position, the intake recieved a few hits during competition. This did not break the intake, but was at risk. A solution would have been to make the lift multi stage so that the intake could have been fully recessed in the robot in the arm's retracted position.

Over the course of the matches, the bolts holding the arm to the driven sprocket of the arm's gearbox would loosen. These bolts were really hard to retighten given the geometry of the surrounding structure. The loose bolts combined with the backlash of the arm would throw off the targeting system for the flywheel, and the programming team had to recalibrate it between each match.

Diag. 9.8, Taken from Preparing for the Game Drop