Shooter
Adjustable hood, weighted flywheel, and a belt-driven turret for auto-aim.
The machine
Two robots,
one season.
Elite Ball Knowledge carried us through States. Then we tore it down and built the Worlds bot around a single question: how fast can one artifact get from the floor to the goal?
01 / Elite Ball Knowledge
Elite Ball Knowledge
Eight motors, six servos, and a colour-sorting carousel. Designed entirely in CAD before a single part was cut, then manufactured in-house on our FabLab's waterjet, CNC, Glowforge, and printers.
- 8Motors
- 6Servos
- 435RPM mecanum drive
- 100+3D printed parts
- 16CNC parts
- 1.7sShooter cycle
Spice Rack
Sorts artifacts by colour using a Geneva mechanism with a powered stick transfer.
Intake
Two-layer compliant roller intake feeding a steep ramp straight into the rack.
Drivetrain
Mecanum belt drive, dual odometry pods, and a PTO that lifts the whole robot.
02 / Iteration
Nothing works
the first time.
Every subsystem on this robot is a third or fourth attempt. Here is what broke, and what we did about it.
Intake
Getting an artifact off the floor and into a sorting slot without stalling, deforming, or jamming it.
V1Active intake
Faster than a four-bar claw, but bootleg wheels caught on the artifact notches and the ramp slope pressed balls flat.
V2Compliant rollers
Silicone rollers and a chain-driven compliant bar. Steeper, flatter ramp with guides to aim the ball at the slot.
- V3
Two-layer compliant
A second powered row with surgical tubing closes the gap above the rollers, so artifacts stop slipping and breaking colour detection.
Spice Rack
The sorter has to stop dead every time the transfer fires — and a gear-driven spindexer never stopped in the same place twice.
V1Simple spindexer
Minimal artifact support. Hard to start and stop cleanly; ended up a centimetre or two out of position and bounced balls back.
V2Geneva mechanism
A Geneva gear lets the motor run continuously while indexing to six fixed stops — under a millimetre of error, tuned to the intake and shooter.
Transfer
Moving a sorted artifact into the shooter fast enough to keep up with the Geneva.
V1Stick transfer
Carried over from our Robot in 5 Weeks bot. Pushed the ball up mechanically, but reset too slowly to use the Geneva's full speed.
V2Servo wheel
An Axon servo driving omni wheels. Right idea, not enough power — balls stalled in the dead space and stopped the rack.
V36000 RPM roller
Motor swap plus a third roller to cover the dead space. Sorted balls now shoot in tandem — 2–5 second cycles including sorting.
Weighted material analysis
We scored every manufacturing route against strength, weight, repairability, quality, time, availability, precision, cost, and complexity. 3D printing won on total value — so it takes the non-structural parts, goBILDA covers boilerplate, and waterjet is reserved for the drivetrain, which takes hits all match.
03 / Worlds
We tore it down
and started again.
After the State Championship we stopped iterating and started over. Built jointly with our sister team SigmaCorns #22377, the Worlds robot trades the spindexer and the lift for a single straight-shoot path — lighter, simpler, and built around one question: how fast can one artifact get from the floor to the goal?
- 2.5sCycle time, down from 8s
- 2×Scoring rate vs. States
- 3Artifacts held
- 360°Shoot-on-the-move turret
Merged storage + transfer
We retired the spindexer entirely and rebuilt storage and transfer as one belted path. Four inner rollers hold a constant 8 mm of compression, four layers of gecko wheels hand off to the shooter, and the whole assembly runs on two 1150 RPM motors over GT2 belts — so the artifact path is identical every single cycle.
Flywheel shooter
Two 6000 RPM motors driving two steel flywheels, with a dynamically integrated hood through 36° of travel and 10 mm of compression. Steel over aluminium bought us RPM stability and sub-second recovery between shots.
Bearing stack turret
A bearing stack on the top plate lets the turret spin without friction from anything below it. We swapped the 435 RPM motor for two Axon servos and freed a motor for the rest of the robot.
Vectoring intake
Curved guides were jamming on multi-artifact pickups, so V3 replaced them with right-biased vectoring wheels, a shallower compliant ramp, and dead wheels at each end that release artifacts while the intake keeps running.
FEA-optimised chassis
Finite element analysis on the drivetrain plates showed us exactly where material was doing nothing. The 15.2″ × 14.5″ result is lighter and faster, with Gripforce wheels, pocketed sideplates, and the battery and four motors low in the base for stability.
Ranking-point strategy
We scored each ranking point against its mechanical cost and committed to the goal RP. That decision let us cut the lift and the brake outright — a lighter, less complex robot aimed squarely at winning matches.