FRC 2022 Game Bot Design A

Diag. 3.16, Taken from Macro Design:: Preparing for the Game Drop

Following that, a vertical linear indexer brings the Cargo up the robot to a single vertical flywheel. 

Diag. 4.4, Taken from Macro Design: Preparing for the Game Drop

The original intention was to make a vertical flywheel with an adjustable hood. This proved to be too difficult with a few prototypes failing to provide a consistent shot. However, the final version of the single vertical flywheel with a static hood was found to be able to vary its shot well enough by varying the speed of the flywheel. A Limelight (generation 1) was used for field orientation to automatically adjust flywheel speeds to sink shots into the Upper Hub.

In order to solve the climbing challenge for the 2022 FRC Game, Rapid React, a combination of a single stage lift and pivot arm were used. The idea was that the single stage lift would raise the robot to the Second Rung. Then the pivot arm would hang on the Rung while rotating the robot to allow the lift to reach the Third Rung. This process would repeat until the robot reached the Fourth Rung.

Diag. 9.31, Taken from Preparing for the Game Drop

Team 4817 was restricted from travelling that year due to COVID-19. In the spirit of coopertition, FRC teams near Port Hueneme competed on behalf of the team. The robot was shipped over on its own.

Robot Design Learnings

This robot would go on to win the Judges Award at the Hueneme Port Regional, in part due to having a well functioning robot. Admittedly, it looks a bit rough around the edges, but functionally it got the job done. 

What Worked Well

The robot drove really smoothly around the field. Off the shelf swerve modules significantly out performed the previous year's 3D printed swerve modules (Ref 17). Parts did not break, and gears meshed together more smoothly. With the opportunity to use such modules more extensively, it was found that not all off the shelf swerve modules were equal. The MK3 modules from Swerve Drive Specialities were better at keeping out dust compared to the X modules from West Coast Products found in Ref 10. This allowed for the swerve modules to operate longer without maintenance (clearing the dust out of the modules). Moving forward, the team decided to only buy swerve modules from Swerve Drive Specialities, as at the time they made the best swerve modules in the team's opinion. 

The robot could shoot from many locations on the field due to the effective combination of the single vertical flywheel and vision tracking from the LimeLight. 

The through bumper intake never jammed, so it was considered a success. 

The robot was able to consistently achieve a Rung 2 climb during competition. 

What Could Be Improved

The indexer's belts on the robot occasionally slipped off the pulleys. The belt were made by cutting and melting Polyurethane cords to form closed loops, while the pulleys were 3D printed. The belts were made by hand instead of commercial toothed belts. Although the ideal distance between pulleys could be calculated, the team struggled to achieve a perfect fit of the belt around the pulleys. When the belts did fall off the pulleys, the robot would be rendered ineffective for the rest of the match. Without the indexer functioning, Cargo could not be brought up the robot to the flywheel. 

Diag. R12.1: The Fitting of Polyurethane Belts to Pulleys

The other main problem was with the climber. When the robot was tested in Singapore, the climb worked well enough. Admittedly, it took a long time for the robot to traverse the Rungs to achieve a 4th Rung climb when inputting the controls manually. Automating the process would have improved the success rate. Unfortunately,  Team 4817 ran out of time to automate the climb. During competition, the climb worked a few times, then proceeded to break in multiple places.

The first was the shattering of driving pinion for the final stage of the arm's gearbox. Without a replacement pinion, the onsite FRC team was not able to get the arm back to a working state.

Diag. R12.2: The Shattering of the Driving Pinion

The other problem was the usage of a 3D printed connector that secured the lift's first stage to the chain. This connector shattered during competition. Luckily, the onsite team managed to repair this problem by using a section of a L channel, which proved to be more effective than the original 3D print.

Diag. R12.3: Replacing the First Stage Connector