Every RC term, decoded

🎗️ 1:16 Scale (Tank Standard) The size that the RC battle tank world settled on, so models from d… 📡 2.4GHz The radio frequency band virtually all modern RC transmitters use,… 🔋 2S / 3S / 4S How many LiPo cells are wired in series. Each cell is 3.7V nominal,… ✈️ 3D Flying Aerobatics flown at or beyond the stall, where the model hangs on i… 🔧 4-Link Suspension A suspension design using four control arms (links) to locate a sol…

📡 ACCST / ACCESS (FrSky) FrSky\x27s two families of 2.4 GHz control protocols — ACCST is the… 🏎️ ARF Almost-Ready-to-Fly — the aircraft equivalent of ARTR: airframe is… 🏎️ ARTR Almost-Ready-To-Run — mostly assembled but needs some electronics (… 📡 ATV / EPA Adjustable Travel Volume / End Point Adjustment — sets the maximum… 🔋 AWG (Wire Gauge) The American Wire Gauge number describing how thick a wire is — the… 🔧 Ackermann Steering geometry that makes the inside front wheel turn more sharp… 🎥 Acro Mode Full manual flight with no self-leveling — the standard mode for FP… 🧰 After-Run Drying Getting all the water out of a model straight after a wet run, befo… ✈️ Aileron The hinged control surface near each wingtip that rolls the plane l… 🎨 Airbrush A small air-powered spray gun that gives fine control over paint fl… 🔋 Amp Draw How much current, in amps, the motor and ESC actually pull from the… 🎥 Analog vs Digital FPV Two video-link technologies: analog is cheap, low-latency and degra… 🎥 Angle Mode / Horizon Mode Self-levelling flight modes where the quad returns to level when yo… ✈️ Angle of Incidence The angle at which the wing is mounted relative to the fuselage cen… 🎥 Antenna Polarization RHCP or LHCP — the transmit and receive antennas on an FPV video sy… 🔧 Anti-squat Rear suspension geometry that controls how much the rear squats und… 🔧 Approach Angle The steepest incline a rig can drive straight up without its front… 🔋 Arm / Disarm The step (a throttle sequence, switch, or button) that enables an E… 🚁 Autorotation An emergency landing technique that uses the main rotor's stored mo…

🎗️ BB Unit An airsoft-style mechanism fitted to some RC tanks that fires real… 🔋 BEC Battery Eliminator Circuit — a small voltage regulator (usually in… 🏎️ BND Bind-N-Drive — comes with electronics but no radio; you bind it to… 🏁 BRCA The British Radio Car Association — the UK national body for radio-… 🎨 Backing Coat A final solid coat, usually white, silver or black, sprayed over ev… ⚙️ Backlash The small amount of free play between meshing gear teeth, most ofte… 🔋 Balance Charger A charger that monitors and charges each LiPo cell individually thr… 🔋 Balance Lead The small white plug on a LiPo pack that gives the charger a separa… ⚙️ Ball Differential A differential using small balls squeezed between two thrust plates… 🔩 Ball Stud A small stud with a ball on top that a plastic cup snaps onto, form… 🏎️ Bashing Driving for fun — jumps, sends and general mayhem — rather than org… 🔋 Battery Connector (XT60/XT90/Deans/EC5) The plug that joins a battery to the ESC. Bigger connectors (XT90,… 🎗️ Battle Mode A tank's configuration for organized IR battles — hit points, respa… 🛞 Bead-Lock Wheel A wheel with a separate ring that clamps the tire's edge (bead) in… 🔩 Bearing A small ring of balls or rollers that lets a shaft spin with minima… 🧰 Bearing Service Cleaning and re-oiling the car\x27s ball bearings, or replacing the… 🧰 Bearing Shield The thin cover on the face of a bearing that keeps grit out and gre… 🔩 Bearing Size Codes Bearings are named by their dimensions in millimetres — inner diame… 🚁 Bell-Hiller The mixing ratio between direct swashplate input and flybar input o… 🔧 Bellcrank Steering A pair of pivoting arms that take the servo\x27s movement and feed… ⚙️ Belt Drive A drivetrain that transfers power using reinforced rubber belts ins… 💬 Bench Racing Talking about setups, gear ratios and what would be fastest, instea… 🎥 Betaflight The most widely used open-source flight-controller firmware for FPV… 📡 Bind Pairing a transmitter and receiver so they talk only to each other. 📡 Binding Phrase A text phrase used by ExpressLRS to generate a unique ID, so any tr… 🎥 Blackbox A flight-data log recorded by the flight controller — used after a… 🚁 Blade Tracking Whether a helicopter's main blades spin in exactly the same rotatio… 🏁 Blinky A spec racing mode where the ESC runs zero timing (a blinking LED p… 🏁 Blue Groove The dark, polished, high-grip strip that forms on a hard-packed cla… 🔩 Body Clip The small wire clip that holds an RC body shell onto its mounting p… 🪛 Body Reamer A tapered hand tool that cuts clean round holes in a polycarbonate… 🪛 Body Scissors Curved and straight scissors made for trimming polycarbonate shells… 🚁 Boom Strike When a main blade flexes down far enough to hit the tail boom. 🔧 Brass Weight Heavier brass replacements for standard parts — knuckles, portal co… 💬 Bricked Electronics that will not respond at all — no lights, no beeps, not… 🔋 Brownout A momentary voltage drop severe enough to reset the receiver or rad… 🔋 Brushless A motor with no physical brushes — more efficient, powerful and lon… 📡 Buddy Box (Trainer Mode) Two transmitters linked together so an instructor can hand control… 🏎️ Buggy A lightweight, low-slung off-road racing car, available in 2WD and… 🔧 Bump Steer Unwanted toe change that happens as the suspension moves up and dow… 🏁 Bump-Up A rule that lets the top finishers of a lower main race move up int… 🔩 Bumper The front or rear protective piece that absorbs light impacts and p… 🔩 Bushing A simple sleeve that a shaft spins inside — cheaper than a ball bea… 🔩 Button-Head Screw A screw with a low, rounded head that sits on top of the part, rath… 💬 Buy Once, Cry Once The advice that paying more for the good version up front costs les…

🔋 C-rating A LiPo's safe continuous discharge rate, as a multiple of its capac… 🚁 CCPM (Cyclic/Collective Pitch Mixing) A swashplate design where three servos spaced 120 degrees apart sha… ✈️ CG (Center of Gravity) A plane's balance point — getting CG right is one of the most criti… 📡 CRSF (Crossfire) TBS's fast, low-latency digital RC link protocol, widely used in FP… 🔩 CVD Constant-Velocity Driveshaft — a driveshaft design that transfers p… 🪛 Calipers A precision measuring tool for reading small dimensions accurately. 🔧 Camber The inward/outward tilt of a wheel viewed from the front. Negative… 🪛 Camber Gauge A gauge that measures the camber angle of a wheel against the chass… 🎥 Camera FOV (Field of View) How wide a view the FPV camera captures, usually quoted as a diagon… 🎥 Camera Tilt (Uptilt) How far the FPV camera is angled upward from level, which sets how… 🎨 Candy Paint A translucent paint sprayed over a metallic base coat, giving a dee… 🔋 Capacitor (Cap Pack) An electrical component on (or added to) an ESC that smooths the vo… 🧰 Car Stand A small stand that holds the chassis with all four wheels off the g… 🔩 Carbon Fiber A strong, lightweight woven material commonly used for high-end cha… 🏁 Carpet Racing Indoor racing on a purpose-made racing carpet instead of dirt or as… 🔧 Caster The backward tilt of the steering axis. More caster = more stabilit… 🚤 Catamaran A twin-hull boat design that rides on two sponsons — common for hig… 🚤 Cavitation When the pressure drop on the back of a spinning propeller blade is… 🔧 Center of Gravity (CG) The point the vehicle\x27s weight effectively balances around. 📡 Channel One controllable function on a radio system — steering is a channel… 🔋 Charge Rate (1C, 2C...) How fast a battery is charged, as a multiple of its capacity — 1C o… 🔧 Chassis Flex How much the chassis itself twists and bends under load, which acts… 🚤 Chine The edge where the bottom of the hull meets the side. 🎨 Chrome Paint A specialist mirror-finish paint that produces a reflective chrome… 🎥 Cinewhoop A small FPV drone with ducted (shrouded) props, built for smooth, s… 🧰 Cleaning Solvents The sprays and fluids used to clean an RC chassis — and the ones th… 🛞 Closed-Cell Foam Tire insert foam made of sealed bubbles, so it holds its shape and… ⚙️ Clutch Bell The bell-shaped drum on a nitro engine that the centrifugal clutch… 🚁 Collective Pitch Changing all main blades' pitch angle together to control lift, ind… ✈️ Control Throws How far a control surface (aileron, elevator, rudder) physically mo… 🧰 Cool-Down Period Letting a motor, ESC or battery sit and cool after a hard run befor… 🚤 Cooling Head A water jacket fitted around a boat's motor or engine that circulat… 🏎️ Crawler A slow, high-articulation RC built to climb rocks and technical ter… 🔋 Cycle Life How many charge-and-discharge cycles a pack will do before its capa…

🎗️ DMD Unit Tamiya\x27s Digital Motor Drive control unit, the speed controller… 🏁 DNF Did Not Finish — a driver who didn't complete the race, whether fro… 🏁 DQ Disqualified — removed from the results, usually for breaking a rul… 📡 DSMX / DSM2 (Spektrum) Spektrum\x27s 2.4 GHz control protocols — DSM2 is the older one, DS… 🎥 DShot A digital signal protocol between flight controller and ESC that se… 🎥 DVR Digital Video Recorder — records the FPV feed (in the goggles or on… ✈️ Dead Stick Flying and landing with the engine or motor stopped, whether by cho… 🚤 Deadrise The angle of a hull's bottom relative to flat — more deadrise handl… 🎨 Decal A pre-printed sticker (sponsor logos, numbers, panel lines) applied… ✈️ Decalage The angular difference between a plane's wing and its horizontal ta… 🚤 Deep-V A hull shape with a sharp V-shaped cross-section, built to cut thro… 🔋 Delta Peak The charge-termination method used for NiMH packs, where the charge… ⚙️ Diff Oil The thick silicone oil inside a gear diff, rated in centistokes (cS… 🧰 Diff Rebuild Opening a differential to clean out the old lubricant, inspect the… ⚙️ Differential A gear or fluid-filled unit that lets the left and right (or front… ✈️ Dihedral The upward angle of the wings from root to tip, which adds passive… 🎥 Diversity Receiver A goggle receiver with multiple antennas that automatically picks w… ⚙️ Dogbone A simple driveshaft with pinned ends shaped like a dog bone — cheap… 🔋 Drag Brake An ESC setting that applies a set amount of braking automatically w… 🏎️ Drift Car A car set up to intentionally slide sideways through corners with t… ⚙️ Drive Cup The cupped fitting on a diff outdrive, transmission or axle that a… 🚤 Drive Dog The small collar that sits on the prop shaft and actually transmits… ⚙️ Drive Pin The small hardened cross pin that locks a driveshaft, dogbone or wh… 🏁 Drivers' Meeting A pre-event gathering where the race director covers the day's form… 🔧 Droop How far a suspension can extend downward from ride height — more dr… 📡 Dual Rate Limits how far a channel travels for full stick input, shown as a p… 🛞 Dually A scale setup running two wheels side by side on each end of the re… 🛞 Durometer (Shore Hardness) A measured hardness rating for tire material, quoted as a Shore num… 🔩 Dust Boot A flexible rubber sleeve fitted over a driveshaft or shock shaft to…

🔩 E-Clip A small, E-shaped metal clip that retains a shaft or pin in place —… 📡 ELRS (ExpressLRS) A popular open-source long-range, low-latency RC link protocol — an… 🔋 ESC Electronic Speed Control — the module that takes the receiver signa… 🧰 ESC Calibration Setting an ESC to recognize your transmitter's exact full-throttle,… 📡 EdgeTX / OpenTX Open-source firmware that runs on many hobby transmitters, replacin… ✈️ Elevator The hinged control surface on the tail that pitches the nose up or… ✈️ Elevon A control surface that acts as both elevator and aileron, used on f… 📡 Expo Exponential — softens the response around the center of a radio cha…

📡 FASST / FASSTest (Futaba) Futaba\x27s 2.4 GHz control protocols — FASST is the long-running o… ⚙️ FDR Final Drive Ratio — the total gear reduction from motor to wheels. 🎥 FPV First-Person View — flying or driving via a live video feed from an… 🎥 FPV Goggles The headset a pilot wears to see the live video feed from the aircr… 🎨 Fade A paint effect where one colour blends gradually into another inste… 📡 Failsafe A receiver safety setting that cuts throttle (and applies brake) if… 🚁 Feathering Shaft The shaft at the rotor head that lets each main blade pitch (rotate… 🚁 Fixed Pitch A helicopter whose main blades are set at one unchanging angle, so… ✈️ Flaps Hinged surfaces on the inner wing that increase lift and drag for s… 🚤 Flex Shaft A flexible driveshaft running from motor to propeller, letting the… 🎥 Flight Controller (FC) The onboard "brain" board on a drone — reads the gyro/accelerometer… 📡 Flight Mode A switch-selected set of transmitter settings — rates, expo, curves… 🚁 Flybar A stabilizing bar mounted above an older-style rotor head that mech… 🚁 Flybarless A modern rotor head design that uses an electronic gyro for stabili… ✈️ Flying Wing An aircraft with no separate fuselage or tailplane — the wing is th… 🛞 Foam Tire A tire moulded from solid foam rather than rubber, used mainly for… 🏎️ Formula RC A 1/10 scale open-wheel class styled after Formula racing cars, dri… 🎥 Frame Size (5-inch, 3-inch, X-Class) An FPV drone's size class, named by prop diameter — 5-inch is the r… 🎥 Freestyle Flying FPV for tricks and style rather than racing against other pi…

⚙️ Gear Differential A differential built from bevel gears in a sealed case, normally fi… ⚙️ Gear Mesh How tightly the pinion and spur gear teeth engage with one another. ⚙️ Gear Pitch / Mod The tooth size standard for pinion and spur gears — Mod (metric) an… 📡 Gimbal (Stick Assembly) The spring-loaded two-axis mechanism behind each transmitter stick… ✈️ Glider / Sailplane An unpowered or lightly-powered plane designed for efficient, susta… ✈️ Glow Engine A small nitro-fueled engine ignited by a heated glow plug — the tra… 🚁 Governor A system that holds the main rotor RPM constant regardless of load,… 🧰 Grease Thick lubricant used where oil would simply fling out — diff intern… 🧰 Ground Loop An electrical interference issue from multiple ground paths in a wi… 🎗️ Gun Elevation Raising and lowering the gun barrel, the up-and-down half of aiming. 📡 Gyro A stability gyroscope that adds automatic counter-steer to help hol… 🚁 Gyro Gain How hard the tail gyro pushes back when it detects unwanted yaw.

🎥 Ham (Amateur Radio) Licence An amateur radio licence, which in the US is generally needed to le… ✈️ Hand Launch Throwing a plane or glider into the air by hand to start the flight… 💬 Hangar Rash Cosmetic scuffs and dings picked up from handling, transport and st… 🚤 Hatch Tape Clear tape run around the hatch to seal the join and keep water out… 🚁 Head Dampers Rubber or elastomer bushings in the rotor head that cushion the bla… 🚁 Heading Hold A tail gyro mode that actively locks the helicopter's nose directio… 🚁 Headspeed The rotational speed of the main rotor, in RPM — the single number… 🏁 Heat / Qualifier A qualifying round used to set the grid for the mains. Drivers are… 🔩 Heat Shrink Plastic tubing that shrinks tight when heated, used to insulate and… 🎗️ Heng Long A Chinese manufacturer whose 1:16 RC tanks make up a large share of… 🪛 Hex Driver (Allen Wrench) The most common tool in an RC toolbox — drives the hex-head screws… ✈️ High-Wing A plane with the wing mounted on top of the fuselage — generally mo… 💬 Hobby Grade A vehicle designed to be repaired and upgraded, with individual rep… 🧰 Hop-Up An aftermarket upgrade part (metal gears, aluminum shocks, ball bea… 🎗️ Hop-Up Chamber The part of a BB-firing unit that puts backspin on each BB for a fl… 🔧 Hub Carrier The part at the outer end of a rear suspension arm that holds the a… 🚤 Hull A boat's main body/shell — displaces water to keep it afloat and sh… 🚤 Hydroplane A hull design that rides up and skims mostly on the surface of the…

🏁 IFMAR The International Federation of Model Auto Racing — the world gover… 🔋 IR (Internal Resistance) A measure of a LiPo cell's health — how much it resists current flo… 🎗️ IR Battle System An infrared "laser tag" setup for RC tanks — each tank fires an IR… 🚁 Idle-Up A flight mode that keeps rotor speed high and constant while the co… ⚙️ Idler Gear A gear placed between two others to pass drive along and reverse th… 🎗️ Idler Wheel An unpowered wheel that tensions and guides a tank's track, usually… 🎗️ Individual Link Tracks Tracks built from separate links pinned together, rather than mould…

🏁 Jump Start Moving off before the start signal is given.

🚤 Keel The weighted fin hanging under a sailboat that stops it blowing sid… 🔧 Kick-Up The upward angle of the front of the chassis, which tilts the front… 🏎️ Kit A model that comes fully unbuilt — every part in the box, nothing p… ✈️ Knife Edge Flying with the wings vertical, so the fuselage side does the lifti… 🔋 Kv A brushless motor's RPM per volt with no load.

💬 LHS Local Hobby Shop — the physical store you buy parts and get advice… 🎥 LOS Line Of Sight — flying or driving while looking directly at the veh… 📡 LQ (Link Quality) The percentage of control packets actually arriving at the receiver… 🔋 LVC (Low-Voltage Cutoff) A safety feature that cuts or reduces motor power when the battery… 🏎️ Large Scale (1/5) Very big RC cars, typically 1/5 scale, often powered by a small pet… 🎨 Lexan Body A clear polycarbonate body shell, painted from the INSIDE so the pa… 🔋 LiFe / LiHV LiFe (Lithium Iron Phosphate) is a safer, lower-voltage LiPo varian… 🔋 LiPo Lithium-Polymer battery — the light, high-power rechargeable pack m… 🧰 LiPo Disposal Retiring a dead, damaged or puffed LiPo pack safely instead of putt… 🧰 LiPo Safe Bag A fire-resistant fibreglass bag or metal container used to charge a… 📡 Logical Switch A programmed switch on the transmitter that triggers automatically… 🎥 Lost Model Beeper An audible alarm you can trigger from the transmitter to help you f…

🔩 M3 / M4 (Metric Sizes) RC hardware is almost entirely metric — "M3" means a 3 mm diameter… 🎗️ MFU (Multi-Function Unit) The main control board in an RC tank that handles drive, turret, so… 💬 Magic Smoke The joke name for the smoke that comes out of an electronic compone… 💬 Maiden The first run or flight of a brand-new or newly built model. 🏁 Main The final race that decides the result, after qualifying. Split int… 🚁 Main Blade One of the two (or more) blades mounted on a helicopter's main roto… 🚁 Main Shaft The central vertical shaft that the main rotor head and blades are… 🏁 Marshal A volunteer stationed trackside during a race to flip over or repos… 🎨 Masking Covering areas of a Lexan body with tape or liquid mask before pain… 🎗️ Metal Upgrade Replacing a tank\x27s plastic parts — gearboxes, tracks, sprockets,… 🏎️ Micro RC Very small models, roughly 1/24 scale and smaller, designed to be r… 📡 Mixing Programming two channels to move together — like elevon mixing on a… 🏁 Mod Class A racing class with open motor and speed-control rules, as opposed… 📡 Mode 2 / Mode 1 (Stick Mode) The convention for which stick does what: on Mode 2 the throttle is… 📡 Model Match A safety feature that refuses to bind or arm unless the receiver ma… 📡 Model Memory A saved settings slot in a transmitter for one specific vehicle — r… 🚤 Mono Hull A single-hull boat design — the traditional RC boat shape, as oppos… 🏎️ Monster Truck A solid-axle truck on oversized tires built for jumping and crushin… 🧰 Motor Break-In Running a new brushed motor gently for the first several minutes to… ✈️ Motor Mount / Firewall The reinforced bulkhead at the front of a plane's fuselage that the… 🧰 Motor Temperature How hot the motor gets in use, checked with an infrared thermometer… 🔋 Motor Timing The ESC setting that advances when it fires the motor's windings. M… 🎗️ Muzzle Velocity How fast a BB leaves an RC tank's barrel, usually measured in FPS —… 🔋 mAh (Capacity) Milliamp-hours: how much charge a pack holds, which is what sets ho…

💬 NIB / BNIB New In Box, or Brand New In Box — a listing shorthand meaning the i… 🔋 NiMH Nickel-Metal Hydride battery — heavier and lower-voltage than LiPo,… 🏎️ No-Prep Drag Car A straight-line drag racer set up to run on an untreated surface, w… 🔋 Nominal Voltage The average working voltage a cell is labelled with — 3.7V for a Li… 🪛 Nut Driver A hex socket on a handle, used for wheel nuts and other nuts you ca… 🔩 Nylock Nut A nut with a nylon collar inside that grips the thread so vibration…

🔩 O-Ring A small rubber ring used to seal a shock shaft or waterproof a comp… 🎥 OSD On-Screen Display — telemetry (battery voltage, flight timer, GPS,… ⚙️ One-Way Bearing A bearing that only transfers power in one rotational direction, le… 🛞 Open-Cell Foam Tire insert foam with interconnected pockets, giving a softer, more… ⚙️ Outdrive The cup-shaped part that connects a differential's output to the dr… 🚤 Outrigger (Rigger) A small stabilizing float mounted out to one side on certain race h… ⚙️ Overdrive (OD/UD) Gearing one axle to turn faster than the other — normally the front… 🎨 Overspray Paint that lands somewhere it shouldn't — controlled with masking t… 🎨 Overspray Film The clear protective film factory-applied to the outside of a new b…

🎥 PID Proportional-Integral-Derivative — the tuning values that set how a… 🏎️ PNP Plug-N-Play — an aircraft with motor, ESC and servos already instal… 📡 PPM Pulse Position Modulation — an older analog protocol that carries s… 📡 PWM Pulse Width Modulation — the classic single-channel servo signal, w… 📡 Packet Rate How many times per second your transmitter sends a control update t… 🏎️ Pan Car An on-road racing car built on a flat plate chassis with very littl… 🔋 Parallel Charging Charging several LiPo packs at once by joining them positive-to-pos… 🎥 Part 107 The US rule set for flying small drones for non-recreational purpos… ⚙️ Pinion The small gear on the motor shaft. More teeth = more top speed (and… 🛞 Pins Small raised knobs moulded across a tire\x27s face that dig into lo… 🏁 Pit / Pit Lane The staging area at a track where drivers prep, charge and repair t… 🚁 Pitch Curve The transmitter setting that maps collective stick position to main… 🚁 Pitch Gauge A tool used to measure and set a helicopter's main blade pitch angl… 🔩 Pivot Ball A suspension design where the hub is held between two threaded ball… 🚤 Planing Hull A hull shaped to climb up and skim across the surface of the water… 🎨 Polycarbonate Paint Flexible paint formulated to bond to clear polycarbonate shells, an… 🔧 Portal Axle An axle with a gear reduction built into each wheel hub, raising gr… 🧰 Power-On Sequence The order you switch things on and off: transmitter on first and of… 🧰 Pre-Run Checklist The quick safety pass before every session — battery secure, screws… 🎥 Prop Propeller — for planes/drones/boats. Rated by diameter and pitch; p… 🚤 Prop Cupping A small lip curled into the trailing edge of each propeller blade,… 🚤 Prop Pitch How far a propeller would screw itself forward in one full turn, wh… ✈️ Prop Size (Diameter x Pitch) The two numbers on a propeller: the first is diameter in inches, th… 🔋 Puffed A swollen LiPo — a sign of damage or abuse (over-discharge, over-ch… 🔧 Punch How aggressively the car accelerates off the throttle — the initial…

🏎️ RC Semi Truck A scale tractor unit that pulls detachable trailers, most commonly… 🏁 ROAR Remotely Operated Auto Racers — the sanctioning body for competitiv… 📡 RSSI Received Signal Strength Indicator — a telemetry value showing how… 🏎️ RTF Ready-To-Fly — the aircraft/heli/drone equivalent of RTR: comes com… ✈️ RTF / ARF / BNF / PNP The four common completion levels sold in the hobby, from a complet… 🏎️ RTR Ready-To-Run — a model that comes fully built with electronics inst… 🏎️ Rally Car A 4WD on-road-style chassis raised up and fitted with all-terrain t… 📡 Range Check A radio mode that deliberately reduces transmit power so you can wa… 🎥 Rates How fast a drone rotates for a given stick deflection in acro mode… 🎨 Rattle Can Hobby slang for an aerosol spray can, the simplest way to paint a b… 🧰 Rebuild Interval How often a given part gets serviced, counted in packs or run hours… 📡 Receiver (RX) The onboard unit that receives the transmitter's signal and passes… 🎗️ Recoil A mechanical or hydraulic effect that makes an RC tank's barrel and… 🎥 Remote ID A US requirement for most drones to broadcast an identification and… 🔧 Ride Height How far the chassis sits above the ground at rest — lower ride heig… 🪛 Ride Height Gauge A stepped or adjustable gauge for setting how high the chassis sits… ⚙️ Ring and Pinion The pair of bevel gears inside a solid axle or gearbox that turn th… 🎗️ Road Wheel One of the wheels running along the bottom of a tank's track that s… 🏎️ Rock Racer A hybrid between a crawler and a buggy — long-travel suspension for… 🔩 Rod End / Ball Cup The cup on the end of a suspension or steering link that snaps onto… 🔧 Roll Center The geometric point a chassis rolls around during cornering, set by… 🛞 Rolling Diameter The overall outside diameter of a mounted tire, which acts as part… ⚙️ Rollout How far the car rolls forward for one full turn of the motor — the… 🚤 Rooster Tail The plume of water thrown into the air behind a fast boat. 🚁 Rotor The spinning main blades that generate a helicopter's lift. 🔋 Rotor (Motor) The spinning magnet assembly inside a brushless motor that the stat… 🛞 Rubber Tire A hollow rubber tire that is normally run with a separate foam inse… ✈️ Rudder The hinged surface on the vertical fin that yaws the nose left and… 🚤 Rudder (Boat) The underwater steering fin at the stern of a boat that turns it, w… 💬 Runner A vehicle that actually gets driven, as opposed to one kept for dis…

📡 SBUS A digital serial protocol that carries many channels over one wire… 🏁 SORRCA The Scale Off Road RC Association — the rule set most scale rock cr… 🚤 Sail Winch The drum servo on an RC sailboat that hauls the sail lines in and l… 🏁 Sanctioning Body An organization (like ROAR, IFMAR or SORRCA) that sets official rul… 🏎️ Scale (1:10, 1:8, 1:5) The size ratio between the model and a real full-size vehicle — 1:1… ✈️ Scale Flying Flying a model that replicates a real aircraft, with a flying style… 🚤 Self-Righting A boat design or feature that flips the model back upright by itsel… 🔩 Self-Tapping Screw A screw that cuts its own thread as it goes into plastic, used thro… 💬 Send It To commit fully to a jump or a run rather than backing off halfway. 🔋 Sensor Wire (Sensor Harness) The flat ribbon cable carrying rotor-position information from a se… 🔋 Sensored A brushless motor with a sensor that tells the ESC exactly where th… 🔋 Sensorless A brushless motor without a position sensor — the ESC estimates rot… 📡 Servo The motor-and-gear unit that turns a channel's signal into physical… 📡 Servo Horn The arm or wheel attached to a servo's output shaft that the steeri… 📡 Servo Reversing A per-channel setting that flips which way a servo moves for a give… 🪛 Servo Tester A small device that drives a servo directly so you can check it wit… 🔧 Servo saver A sprung link in the steering that flexes on impact so a hard hit d… 🔩 Set Screw A small screw (often driven into a pinion gear or wheel hex) that l… ⚙️ Shaft Drive A drivetrain that transfers power through a solid metal shaft rathe… 💬 Shelf Queen A model built or bought to look good on a shelf that never actually… 🔩 Shim A very thin washer used to take up slack or set the exact spacing o… 🔩 Shock The spring-and-oil damper at each corner of a suspension that absor… 🔧 Shock Limiter A spacer fitted inside a shock, over the shaft, so it cannot compre… 🔩 Shock Oil The fluid inside a shock that controls damping. Thicker (higher wei… 🔧 Shock Piston The small drilled disc on the end of the shock shaft that forces oi… 🔧 Shock Rebound How quickly a shock pushes back out after being compressed. 🧰 Shock Rebuild Stripping a shock to renew the oil, o-rings and any worn shaft or p… 🏎️ Short Course Truck A pickup-styled off-road racing truck on 4-link or independent susp… 🛞 Sidewall The side of a tire between the tread and the wheel — its flex and s… 🚁 Size Class (450 / 500 / 700) The shorthand numbers used to describe how big a helicopter is, fro… 🔧 Skid Plate A replaceable plate underneath the chassis that takes the impacts a… ⚙️ Slipper clutch An adjustable friction clutch on the spur gear that lets the drivet… 🎗️ Smoke Unit A small heater that vaporises smoke fluid to send a puff of exhaust… 🔋 Soldering Joining wires and connectors with molten solder — the standard way… 🔧 Solid Axle A one-piece axle where both wheels at that end are mechanically lin… 🎗️ Sound Unit An onboard speaker and amplifier module that plays real engine, fir… 🏁 Spec Class A racing class where the rules lock down key parts (motor, tires, o… 🏁 Spec Tire A rule requiring everyone in a class to run one specific approved t… 🏎️ Speed Run Car A car built purely to record a top speed over a measured stretch of… ✈️ Spinner The rounded cone fitted over a plane's prop hub — smooths airflow i… 🚤 Sponson One of the two outer hull sections on a catamaran that provides lif… ⚙️ Spool A locked (non-differential) axle where both wheels are forced to sp… 🎥 Spotter (Visual Observer) A second person standing with the pilot who keeps their own eyes on… 🎨 Spray Ventilation and PPE The habit of spraying only in a well-ventilated space with the righ… 📡 Spread Spectrum Modern radio technology (used by 2.4GHz systems) that hops between… 🔧 Spring Rate How stiff a shock spring is — the force needed to compress it a giv… 🎗️ Sprocket The toothed wheel that drives a tank's track, usually at the front… ⚙️ Spur The large main gear the pinion drives. Set the pinion-to-spur mesh… 🎥 Stack (FC/ESC Stack) The flight controller and ESC combined into a compact bolted-togeth… 🏎️ Stadium Truck A 1/10 scale off-road racer, most often 2WD, with a truck body and… 🏁 Staging Being called up for your race — you place your car on the starting… ✈️ Stall When a wing loses lift because it's flying too slow or at too steep… 🔩 Standoff A threaded post or spacer that holds two parts a set distance apart. 🔋 Stator The stationary part of a brushless motor: the laminated iron teeth… 🏁 Stock Class A class limited to a specific, lower-power motor spec — as opposed… 🧰 Storage Prep Getting a model ready to sit unused for weeks or months. 🔋 Storage charge Bringing a LiPo to about 3.8V per cell for storage — the voltage th… 🧰 Stripped Thread A screw hole (or screw head) that no longer holds because the threa… 🚤 Strut The shaft housing that supports a boat's propeller shaft where it e… ⚙️ Stub Axle The short shaft in the hub carrier that the driveshaft drives and t… 🚤 Stuffing Tube The tube running through the bottom of the hull that the flexible d… 🎥 Sub-250 g A class of very light aircraft weighing under 250 grams ready to fl… 📡 Sub-Trim A small electronic offset that shifts a servo\x27s centre point so… 🚁 Swashplate The mechanical assembly below the rotor head that tilts the main ro… 🔧 Sway Bar (Anti-Roll Bar) A stiff wire linking the left and right suspension that resists bod…

🏁 TQ Top Qualifier — the driver who set the fastest qualifying result, e… 🎥 TRUST (Recreational UAS Safety Test) In the US, a free online safety test that recreational flyers must… 🚁 Tail Boom The tube running back from the frame that carries the tail rotor as… 🚁 Tail Drive (Torque Tube / Belt) How power gets from the main gear back to the tail rotor — either a… 🚁 Tail Rotor The small rotor at the tail that counters the main rotor's torque a… ✈️ Taildragger (Conventional Gear) A plane with two main wheels ahead of the centre of gravity and a s… 🎗️ Tank Gearbox The geared drive unit on each side of the tank that turns a motor i… 🏁 Tech Inspection An official check that your car actually meets the rules for the cl… 📡 Telemetry Live data sent back FROM the vehicle to the transmitter — pack volt… 🪛 Temp Gun (IR Thermometer) A point-and-shoot infrared thermometer for checking motor, ESC and… ✈️ Thermal A rising column of warm air a glider pilot circles inside to gain a… 🧰 Thermal Runaway The self-feeding reaction inside a damaged or overcharged lithium c… 🔋 Thermal Shutdown Built-in ESC protection that cuts or heavily reduces power when the… 🔩 Thread-Lock (Loctite) A liquid applied to screw threads that keeps them from vibrating lo… 🚁 Throttle Curve The transmitter setting that maps stick position to engine or motor… 📡 Throttle Cut A switch that forces the throttle channel to a shut-off value regar… 🚁 Throttle Hold A switch that drops the engine to idle or cuts the motor entirely w… 🎥 Tiny Whoop A tiny, lightweight ducted-prop FPV drone (typically 65-75mm) safe… 🛞 Tire Balancing Checking a mounted wheel for heavy spots and adding small weights s… 🛞 Tire Compound The rubber hardness/softness of a tire. Softer compounds grip harde… 🛞 Tire Glue Cyanoacrylate (CA) glue used to bond a tire to its wheel — applied… 🛞 Tire Insert A foam ring fitted inside a tire before gluing, supporting the side… 🛞 Tire Truing Machining a mounted tire on a spinning arbor so it runs perfectly r… 🔩 Titanium Hardware Screws, turnbuckles and shafts made from titanium instead of steel… 🔧 Toe Whether the wheels point slightly in (toe-in) or out (toe-out) view… 🔧 Torque Twist The chassis lifting or leaning to one side under hard acceleration,… 🏎️ Touring Car A low, road-going race car body on a flat, on-road chassis — raced… 🏁 Track Call A stoppage or pause of the race called by race control. 🎗️ Tracks The continuous rubber or plastic belts an RC tank drives on instead… 🔧 Traction Compound A liquid or additive applied to tires (mainly on-road/carpet racing… ✈️ Tractor vs Pusher A tractor prop sits at the front and pulls the aircraft; a pusher s… 🏎️ Trail Truck A scale-focused 4WD truck meant for driving trails at a realistic p… ✈️ Trainer A plane designed to be forgiving for a first-time pilot — typically… ⚙️ Transfer Case The gearbox on a crawler or scale truck that splits drive from the… ⚙️ Transmission (Gearbox) The gear case that takes drive from the spur gear and passes it on… 📡 Transmitter (TX) The handheld radio you actually hold — sends your stick and switch… 🏁 Transponder A small device on the car that a track's timing loop reads to recor… 🛞 Tread Pattern The molded pattern on a tire's surface, matched to the surface it's… 📡 Trim A small adjustment to a channel's center/neutral point — used to fi… 🚤 Trim Tab An adjustable underwater tab at the stern that fine-tunes how the b… 🏎️ Truggy A 1/8 scale 4WD racer built on buggy running gear but wider, taller… 🚤 Turn Fin A small fin mounted near the propeller that helps a boat corner cle… 🔩 Turnbuckle An adjustable threaded link (often a suspension or camber link) tha… 🪛 Turnbuckle Wrench A slotted wrench that grips the flats of a turnbuckle so you can ad… 🔋 Turns (T) The number of wire windings on a brushless motor — the traditional… 🎗️ Turret The rotating upper section of a tank carrying the main gun, able to… 🎗️ Turret Traverse The side-to-side rotation of the turret on its ring. 🎥 Turtle Mode (Flip Over After Crash) A flight controller feature that reverses selected motors so an ups… 🔧 Tweak A twist in the chassis or suspension that makes one corner sit lowe…

🔧 Unsprung Weight The weight of parts that move with the wheel rather than the chassi…

🎥 VLOS / BVLOS (Visual Line of Sight) VLOS means you can see the aircraft with your own unaided eyes thro… 🎥 VTX Video Transmitter — the onboard transmitter that beams the FPV came… 🎥 VTX Power (25mW–600mW+) How much power an FPV video transmitter puts out — higher power rea… 🎨 Vinyl Wrap Printed adhesive vinyl applied to a body as an alternative to spray… 🔋 Voltage Sag The temporary drop in a battery\x27s voltage while it is under heav…

✈️ Warbird A scale RC replica of a WWII-era military aircraft — typically fast… ✈️ Washout A deliberate twist built into a wing so the tips are at a lower ang… 🚤 Water Pickup A small tube that draws water from around the propeller to cool a b… 🚤 Water-Cooled ESC A speed controller fitted with a cooling plate that lake water is p… 🧰 Waterproofing Sealing the electronics and protecting the metalwork so a model can… 🔋 Watt A unit of electrical power — volts × amps. The real-world measure o… 🔋 Watt Meter (Power Meter) An inline meter fitted between battery and ESC that reads real volt… 🔋 Watt-Hours (Wh) A pack\x27s total energy — nominal voltage multiplied by capacity i… 🎨 Weathering Techniques (dry-brushing, oil wash, pigments, salt chipping) that m… 🔧 Weight Transfer How much grip shifts from one end/side of a car to the other under… 🛞 Wheel Dish How deep-set a wheel's face is relative to its outer lip — a stylin… 🔩 Wheel Hex The hexagonal adapter that connects a wheel to the axle and transfe… 🛞 Wheel Offset How far a wheel's mounting face sits from its centerline — changes… 🔧 Wheelbase The distance between the front and rear axle centerlines — a bigger… 🔧 Wheelie Bar A small wheeled arm sticking out behind the car that stops it flipp… 🎨 Window Mask Pre-cut sticky masks supplied with a body that cover the windows so… ✈️ Wing Loading A plane's weight divided by its wing area. Lower loading flies slow… ✈️ Wingspan A wing's total tip-to-tip length — the standard way RC plane sizes… 💬 Wrenching Working on your vehicle — building, repairing, maintaining or tunin…