This page is for acronyms, abbreviations, and technical terms used in RC. Please leave out chat/IM acronyms like lol, IMHO, etc.
Electronic Terms
ESC - Electronic speed control
MSC - Mechanical speed control
BEC - Battery elimination circuit. this eliminates the need for a receiver pack on electric models by taking power for the radio gear from the main battery used for the motor.
NiCD - Nickel Cadmium. A type of cell chemistry for rechargeable batteries. Available in MaH ratings up to 2400.
NiMH - Nickel metal hydride. A type of cell chemistry for rechargeable batteries. Available in higher MaH ratings than NiCD (3700+).
mAH - Milliamp hours. This is the capacity of your batteries. The larger the number, the longer it will provide power, assuming the same electronics/motor.
Brushes - The part of an electric motor that delivers current from the motor leads to the comm. they are stationary on the end bell, and must be replaced when they wear down.
Comm. - Commutator. This is the part of the electric motor the carries current form the brushes to the windings. It is attached to the armature. After a while it becomes worn and blackened, and must be trued. this is done with a 'Comm. cut,' in which a lathe is used to make the comm smooth, clean, and perfectly round.
Turns - This is the number of times the armature wire is wrapped arond the armature. generally, lower turn motors are faster, while higher turn motors have more torque.
Winds - The number of strands in the armature wire. Motors usually have 1-4 winds. More winds... While less winds... Turns and winds are noted in the format of '--x-', with the first number being the number of turns, and the second number being the number of winds. ex: 15x2 denotes a 15 turn, double wind motor.
Armature - The motor shaft of an electric motor, with the turns and winds attached. Also holds the comm.
BL - Brushless. A type of electric motor that does not use brushes. Instead of brushes, it has fixed windings on the motor can and rotating magnets on the motor shaft. It needs a special ESC, usually called a controller, to provide power.
Nitro Terms
Clutch Bell/CB - This is the combined clutch bell and 'pinion' gear for a nitro engine on some models. It attaches to the motor shaft and rides on bearings. As engine RPM's rise, the clutch shoes engage the clutch bell, turning the rest of the drive train. It can also be changed to manipulate gearing.
OWB - One-way-bearing, AKA roller clutch. This is a bearing that spins free in one direction, and locks in the other. It is used on electric starters, shaft starters, and pull starters on nitro engines to engage the starter shaft. There is also a one way bearing in two speed transmissions, to disengage the first gear after the second gear is engaged via the 2 speed clutch.
Starter box - Starter box
FOC - Forward only conversion. Just what it sounds like. It converts a reverse capable nitro vehicle into a forward only machine. This cuts down on rotating mass, and is mostly used in racing .
P/S - Piston/sleeve. These are the internals of a nitro engine. The sleeve forms the sides of the combustion chamber, and the piston moves up and down inside the sleeve, turning the crankshaft. Often when an engine loses compression, the P/S is to blame, and can be replaced. When the P/S is replaced, the new set must be broken in, just like when the engine was new.
HSN - High speed needle. Used to adjust the fuel/air mixture at high speeds.
LSN - Low speed needle. Used to adjust the fuel/air mixture at low speeds.
TDC - Top dead center. When the piston is at the very top of its stroke. In a new and/or well maintained engine, you should be able to feel significant pinch as the piston reaches TDC. this indicates a tight (well-sealed) fit between piston and sleeve. If the piston is left in this position after the engine is stopped, it can become stuck as the engine cools and contracts. This can be remedied by prying the flywheel around with a screwdriver.
BDC - Bottom dead center. When the piston is at the very bottom of its stroke. move the piston here to prevent it from getting stuck when the engine is stored.
BB - Usually means a 'Big Block' engine. Refers to engines with ??? displacement and up.
ARO - After run oil. Oil that is put in a nitro engine after is has been run and is being put away for the day. it keeps the engine from rusting as well as keeps it lubed.
'Nitro - Fuel that you put into the fuel tank on a nitro vehicle. Most of the time it is blue or pink. There have been some stories of people accidently putting this horribly expensive liquid into the washer fluid bottle on a real car. This should not be confused with gasoline, since many new people say gas instead of nitro, or just fuel. Gasoline powered rcs are also available.
Tranny - Transmission. Receives power through the spur gear and transfers it to the wheels. It sometimes features reverse and/or two or more speeds. Reverse is only found on nitro models, as electric motors can turn in either direction, and multi-speeds are sometimes used with electrics.
Diff - Differential. This is between the two halfshafts (axles) that connect to each wheel. It allow them to turn at different speeds to make turns smooth.
WOT - Wide open throttle. Applies to both nitro and electric models, although on electric models it is somewhat figurative. It just means that the throttle is at full.
TX - Transmitter. The radio you hold in you hand to control the model. Also used to refer to the transmitter crystal.
RX - Receiver. The small electronic device that receives signals from the TX and sends them to the servos/speed control. Also used to refer to the receiver crystal.
X-Tal/Crystal - The device the tunes your radio to a certain frequency. Also known as the 'channel' your radio is on. TX and RX crystals must be on a matching frequency for them to work together. Multiple models can be operated in one area (track, bashing spot, etc.) if they are on different channels.
LHS - Local hobby shop. This is the place down the street/across town where you can go to buy parts and get help and advice in person. Most are staffed by knowledgeable people who know their stuff and give good advice, but beware, this is not always true.
Spur Gear - The large (usually plastic) gear that meshes with the clutch bell or motor. It is on the primary shaft of the transmission, or mounted to the center diff, and can be used to manipulate gearing.
Pinion- This is the small gear attached to the motor shaft of an electric motor. It can be changed out with other gears with different tooth counts in order to manipulate the gear ratio. Most two speed clutch bells and some single speed clutch bells have pinion gears that thread onto them, instead of changing the whole clutch bell.
Truggy - Truggy