Small and Simple

• 26”x 26” square chassis.

• 2” x 1” box tube of ⅛” wall.

• 1.25” ground clearance to bumper.

Electronics

• Battery mounted below the chassis rails: keeps the center of gravity as low as possible.

• Foam battery cage: protects the battery from rattling around while driving.

• Grommet holes: strategically placed for easy wire routing.

• Mirrored electronic mounting holes: flexibility in component placement.

Swerve Drive

• 4 MK4 SDS swerve modules (details in the following section).

• Protector panels (not shown): prevent game elements or robots from interfering with each module.

Module Information

• Swerve Drive Specialties (SDS) MK4 modules.

• L4 option - 5.14:1 gear ratio.

• 21 lbs for all 4 swerve modules.

Motors and Sensors

• Azimuth rotation: controlled by a Falcon 500 motor.

• Drive wheel: controlled by a Falcon 500 motor.

• Wheel orientation: measured by a CTRE SRX Mag Encoder.

Robot Optimization

• Four independent modules: take up small volumes, which allow for the optimum design of other subsystem mechanisms

• The simplicity of this COTS module and the ease of making the rest of the chassis allow the team to focus more time and effort on other robot subsystems.

Rollers for Acquiring Roller

• VersaTube: lighter and sturdier while still accounting for cargo compression.

• 7.3” gap from the ground to the roller.

• Bottom roller and grip tape: increases traction on cargo.

Powering the Intake

• Falcon 500:  powers the top roller, with the middle/bottom roller belt-driven off the top.

• The Intake roller spins with a 1.33:1 reduction.

Deployment

• Two Intake tensioning bands: surgical tubing attached from the intake to the chassis; allows the intake to snap down when the bottom roller spins at the start of a match.

Superstructure

• Four vertical 1”x1”  .049” WD box tubes: light and rigid frame.

• Redirect panels: 2 polycarbonate panels, bent at 140 degrees, funnel cargo into the indexer.

Motor and Belt

• One Falcon 500 motor: geared to 2.88:1.

• Two axles spin in opposite directions using a 1:1 gear ratio.

• 2” tube rollers covered with thread are used to move cargo through the indexer and into the shooter.

Cargo Rails

• Maintains a constant compression on cargo.

• Layer of tread on the rails: slightly increases traction and ensures that cargo is not damaged while passing through the indexer.

Turret

• Powered by a 60:1 reduction with a NEO motor.

• Custom 120 tooth 10 DP polycarbonate gear: the final stage of the turret reduction.

• 11” bore in the middle for cargo to pass through from the feeder into the flywheel of the shooter.

• Bearing stack-ups held together by press-fit dowels, securely holding the shooter, while still allowing for smooth rotation for the turret mechanism.

Flywheels

• Primary flywheel: 4” diameter 35A durometer neoprene roller powered by one Falcon 500 with a 1:1 belt-driven reduction.

• 2” diameter top roller belted from the main axle at a 1:1 gear ratio reduces backspin by 50% to ensure that cargo does not bounce out of the hub.

Hood

• Hood mechanism: powered by 1 NEO 550 geared to a total reduction of 454:1.

• Hood travel: operates through a custom 3D-printed sector gear, with the pitch diameter equivalent to a 436 tooth 20 DP gear.

• Sector gear: provides the shooter with a 24-degree range of motion, and directly makes contact with the cargo as it travels up through the shooter system during a shot.

Design Goals

• Extends 75” above the ground.

• “Dynamic stage”: can pivot to 45 degrees.

• Horizontal reach of 11” off the front chassis rail.

Extension Gearbox

• Extension/retraction: powered by 2 Falcon 500s.

• ~6:1 single reduction gearbox.

• Falcons 1.25” off the ground: keeps the CG as low as possible.

• Power: transmitted to the carriage through a #25H chain.

Dynamic Arm

• Pivoted by a single Neo 550 with a single-stage spur gear reduction and 2 stage versa planetary for a total reduction of ~97:1

• Rubber standoffs: overlapping the rung area to reduce swinging by increasing friction

• 1.25” OD round tube to maximize rotational stiffness

Static Arms

• Two 2”x 1” ⅛ wall tubes mounted on a custom gearbox/climber base, only 9” wide.

• Strengthened by turnbuckle tie rods that extend to the outer chassis rails.

• One-way spring-loaded hooks: in the process of transferring the rung so the dynamic can grab the next.

Lift Carriage

• Bearings in 2 axles: to constrain the carriage.

• Uses .875” aluminum tube for a dead axle with bronze bushings as a dynamic pivot point

• Attaches to the chain using 5 shear pins to distribute the load