New! Companion Team Curriculum now available!
Courtesy of FRC Team 4817: One Degree North
Designed by new FRC CAD members during the 2021 FRC off-season, this robot served as a testing ground for designing and integrating an FRC file.
As the focus was on building basic skills rather than functionality, members were allowed to try designing mechanisms anyway they wished, even if the plan was rather ambitious.
The robot was designed to have a west coast drivebase with a shifting gearbox. A west coast drivebase is the simplest effective drivebase for the team to design from scratch. In order to further challenge themselves, they added a gearbox which potentially allows for the drivebase to either accelerate more effectively (by shifting gears) and to use a lower gear to increase the torque of the drivebase in a potential pushing match.
As this is a robot meant for the 2017 FRC Game, Steamworks, the primary game object, Fuel is a game object that is meant to be shot. (To reduce the scope of the project, the secondary game object of gears was ignored.) The robot features a very wide through bumper intake that brings balls high up into the robot to drop balls into the large moving floor indexer.
Unfortunately this design was never fully completed nor was there a build attempt. However, looking at the file some design features stand out.
Despite being designed by new FRC members, 4817 still used this as an opportunity to try to design some more uncommon mechanisms to expand the design team's repertoire.
The drivebase's gearbox was successfully designed to include a pneumatic shifter and dog gears to allow for the drivebase to have multiple torques.
Diag. 2.15, Taken from Preparing for the Game Drop
The single vertical flywheel of this robot was designed to have an adjustable hood, a first in Team 4817's history. After thinking through the best way to create such a hood, it was determined that using bearings to hold a 3D printed curved hood with a gear profile on the perimeter (similar to holding stock in a lift) was the best way to design such a hood.
Diag. 5.7, Taken from Preparing for the Game Drop
As the project was not brought to completion, there are some missing parts. The indexer does not have the necessary walls to hold fuel cells. The flywheel does not have the mounting structure or the intended turret under it. It can also be noted that the different mechanisms of the robot do not join together very effectively. Part of the indexer's base plate goes into the intake's volume. The entire indexer is built off of a few towers with many pieces of horizontal stock, almost as if the robot had a "second floor." Planning out more effectively how the different mechanisms were meant to integrate together could have made the structure flow more seamlessly (without the somewhat redundant pieces of stock forming the "second floor" of the robot) as well as properly join the various mechanisms together. This problem was expected given the new designers set out to create an ambitious design for their first group project. Experiencing the kind of issues that arise during integration without proper planning is an invaluable experience.
To see the more successful iteration of this off-season project by Team 4817 refer to Ref 18. To see more full fledged designs for the Steamworks game, refer to Ref 13 and Ref 19.
* Further explanation of the various mechanisms in FRC Handbook Volume 1.