⚙ FRC Robotics Calculator

Drivetrain · Swerve · Shooter · Arm · Elevator · Climber · Intake · HTD-5 Belt · Tubes · Electrical · Gearing

Drivetrain Traction Shooter Arm & Elev Intake Climber Tubes Electrical Gearing HTD-5 Belt Projectile Auto

Motor & Gearing

Motor (per side)

Motors/side

Gear ratio

Wheel diam (in)

Robot weight (lbs)

Efficiency (%)

Target 12-16 fps. Accel >15 ft/s² is excellent.

Swerve Module Ratio click to use

Filter vendor All vendors SDS — MKSwerve REV Robotics West Coast Products Thrifty Bot

Module / level — select to apply

Traction & Wheel Slip

Wheel type Colson / Nitrile (μ=1.1) Traction wheels (μ=0.9) Mecanum (μ=0.7) Omni (μ=0.5) Smooth / carpet (μ=0.3) Custom (empirical)…

Normal force (lbs)

Slip force (lbs)

Effective μ

Robot weight (lbs)

Traction wheels

μ = slip force ÷ normal force. Measure with a fish scale on carpet.

μ Reference

Colson / Nitrile on carpet1.1

Traction wheels on carpet0.9

Mecanum on carpet0.7

Omni on carpet0.5

Smooth wheel on carpet0.3

Wet / slick surface0.2

Flywheel Shooter

Motor

Motor count

Ratio (m:fw)

Flywheel diam (in)

Flywheel mass (lbs)

Ball mass (lbs)

Target exit (fps)

KE ratio ≥ 2× = minimal RPM drop per shot.

KE from RPM

Flywheel RPM

Flywheel diam (in)

Flywheel mass (lbs)

Ball mass (lbs)

Hood shooters transfer ~80% of flywheel KE.

Arm / Pivot

Motor

Motor count

Gear reduction

Arm length (in)

Arm + load (lbs)

Efficiency (%)

Safety factor ≥ 2× required. Target 90–180°/s.

Elevator / Linear

Motor

Motor count

Gear reduction

Drum radius (in)

Load mass (lbs)

Cascade stages 1 — single2 — cascade3 — triple

Intake Roller

Motor

Ratio (m:roller)

Roller diam (in)

Game piece diam (in)

Surface speed 1.5–3× drive speed prevents jamming.

Indexer / Conveyor

Type Flat belt (1:1, 2" pulley) Roller pair (1:1, 2" OD) Tube indexer (1.5:1, 3") Snap-action Colson (2:1, 4") Custom…

Motor

Ratio (m:roller)

Roller diam (in)

Path length (in)

Shooter target RPM

Feed game piece when flywheel ≥ 95% of target RPM.

AM Climber in a Box

Preset AM Climber 10.5:1 (CIM) AM Climber 21:1 (CIM) AM Climber NEO 10.5:1 Custom…

Motor

Gear reduction

Motor count

Efficiency (%)

Spool radius (in)

Robot weight (lbs)

Climb height (in)

Climb Analysis

Time available (s)

Hook height (in)

Rope stretch Dyneema / Spectra (0%) Nylon webbing (~2%) Bungee (~5%)

AM stock spool ≈ 0.75". 10.5:1 for <100 lbs, 21:1 for heavier.

Climber Tube Parameters

Target climb height — bottom to bar (in)

Mount height (in)

Hook length (in)

Min overlap (in)

Wall thickness (in)

Stages 1 — single tube 2 — cascade 3 — triple cascade

Stage Breakdown

Size OD down ~0.125" per stage. Add 1–2" to inner tubes for stops. Use 1/16" wall 6061-T6.

Power Budget

Drive motor count

Drive avg A/motor

Other motor count

Other avg A/motor

RoboRIO + radio + misc (A)

Keep avg draw under 80A. Main breaker: 120A. Battery: 18Ah.

Wire & Battery

Current (A)

Run length (ft)

Peak current (A)

Int. resistance (mΩ)

Fresh battery: 10–15 mΩ. Old: 20–40 mΩ. Brownout below 6.3V.

Compound Ratio

Input RPM

S1 driver

S1 driven

S2 driver

S2 driven

S3 driver

S3 driven

Center Distance

Type Spur gear (DP)Chain sprocket

Pitch 20 DP32 DP #25 chain (0.25")#35 chain (0.375")

Driver teeth

Driven teeth

HTD-5 Belt 5mm pitch

Driver teeth

Driven teeth

Center distance (in)

Motor free RPM

Belt width 9 mm15 mm25 mm

Aim for ≥6 teeth in mesh to prevent skipping.

Belt Finder

Enter pulleys + desired center → find nearest standard belt. Click to use.

Driver teeth

Driven teeth

Desired center (in)

Projectile Shot

Launch speed (fps)

Launch angle (°)

Launch height (in)

Target height (in)

No air resistance. Add 5–10% speed margin for foam pieces.

Auto Drive Profile

Distance (in)

Free speed (fps)

Acceleration (ft/s²)

Throttle limit (%)

Auto Drive Profile

Distance (in)

Free speed (fps)

Acceleration (ft/s²)

Throttle limit (%)

Trapezoid: ramp up → cruise → ramp down.