Bryn Heinemann

Work

FIRST Robotics: FTC and FRC Robot Design

FIRST Tech Challenge (FTC) and FIRST Robotics Competition (FRC), high school. 2018 to 2022.

Competed

Designed and machined FTC 15281's 2018-19 robot: a 4-degree-of-freedom (4-DOF) arm that scored game elements into the lander, and a latch that raised and lowered the 30 lb robot. Design lead on FRC 6831 from 2020 to 2022.

My role.Designer and machinist. Did most of the programming, integration, and fabrication; the build team was mostly one teammate and me.

Fig. 1.The 4-DOF arm reaching into the crater for game elements and scoring them into the lander.

FTC 15281 robot

In the 2018-19 Rover Ruckus game, robots scored minerals into a lander and, at the end of the match, latched onto the lander and hung from it.

Robot 15281: frame, arm drive, and latch.
Fig. 2.Robot 15281: frame, arm drive, and latch.
Fig. 3.The robot driving off the lander after lowering itself from the latch.

Added servo-driven intake and eject at the end of the arm, a fifth driven axis.

Failure mode: the arm failed under its own torque, from the robot's center of gravity combined with the arm's torque on a long lever. New gear ratios fixed it.

FTC 8176 shooter

J-shooter for FTC 8176 Steelhead, 2020-21. The Ultimate Goal game required shooting foam rings into high goals and power shots from varying distances. The launcher had to be compact, serviceable, and fit a differential swerve drivetrain.

Contributions

  • Designed a curved ring path, adapted from FRC shooters, that guides each ring around a flywheel before release for more contact time
  • Modeled it parametrically in CAD: flywheel placement, ring compression, and mounting; bearing-supported shafts, timing belt drives, standard hardware, and many 3D-printed parts
  • Evaluated linear belt-driven and flywheel-only concepts; the belt-driven concept had friction and ring slippage
  • Built a prototype on a test chassis; testing showed sensitivity to ring guidance and ramp geometry, so I refined ring alignment, transition surfaces, and compression
Printed J-shooter, the final part.
Fig. 4.Printed J-shooter, the final part.
Sketch of the ring path. Dimensions in mm.
Fig. 5.Sketch of the ring path. Dimensions in mm.
Full robot CAD, FTC 8176, with the shooter mounted.
Fig. 6.Full robot CAD, FTC 8176, with the shooter mounted.

Team result: Inspire Award 3rd place, 2021 Oregon State Championship.

Other teams

  • FTC 4143 Mocha, 2019-20: designed the robot
  • FRC 6831 A05 Annex, 2019 to 2022: team member, then design lead from 2020 to 2022