Calculators & tools
Free web calculators for the design math on this wiki. Always sanity-check a calculator’s output against a hand estimate before you cut metal.
Part selection
Section titled “Part selection”- Ember Drivetrain Calculator — Wheel speed, gear ratio, and drivetrain performance. See Power, torque & gearing.
- Team Run Amok Tentacle Calculator — Long-standing drivetrain / amp-hour model: pushing-match current and pack capacity from motors, voltage, gearing, wheel size, and robot weight.
- Ember Weapon Tip Speed Calculator and Bristol Bot Builders Tip Speed Calculator — Spinner RPM and tip speed. See Weapon geometry & bite.
- Ember Robot Builder — Step-by-step design of a complete robot powertrain.
Mechanical design
Section titled “Mechanical design”- Ember Center Distance Calculator and WCP Belt Calculator — Pulley centre-to-centre distance for a belt profile and tooth counts. See Weapon motors & ESCs.
- Ember Scale Factors — Convert linear dimensions between weight classes. See Weight budgeting.
Electrical
Section titled “Electrical”- Ember Battery Size Calculator — Pack capacity from current draw, discharge rate, and runtime. See LiPo & LiHV batteries.
- Ember Watt-Hour Equivalency — Equivalent capacities when changing cell count or voltage.
- Ember Motor Torque Calculator (beta) — Motor torque, output torque, and linear force from motor specs.
Safety
Section titled “Safety”- Ember Audio Tach Calculator — Estimate weapon tip speed from an audio recording to check rule compliance.
Strategy
Section titled “Strategy”- Ember Tournament Calculator — Fight counts and RCL point distribution for a bracket.
Guides & references
Section titled “Guides & references”- Beetleweights for Dummies (Leo Ping, with Lucas Skotiniotis, Ian Talbert & Derek Tran; Fall 2025) — a current, builder-maintained beginner guide to 3 lb robots, shared through the NHRL Discord. Much of this wiki’s North-American beetleweight practice is cross-checked against it.
- RioBotz Combat Robot Tutorial (Meggiolaro, PUC-Rio) — the deep reference for the underlying engineering: drivetrain, spinner energy, bite, shaft and bearing design, materials.
- SPARC — the construction, match, and tournament rules most North-American events adopt.
- NHRL wiki and Bristol Bot Builders guides — event procedure, radio setup, and tech-inspection detail.