01536 725416

A-Z Glossary

Armature - The inside part of the motor which spins when current is passed through it.

Axle - The assembly in which the wheel attaches to, the wheel is secured by a nut one end and usually a pin with a hex shaped adaptor for the wheel to connect to on the other side.

Ball cup - The part found on the end of an adjustable rod used for setting the camber and toe of the wheels.

Bearing - A circular shaped item with small metal balls within it used to remove/reduce drag in the drivetrain or a motor. Cheaper versions are made of solid metal or plastic and are less effective.

Brushes - There are two of these on a standard brushed motor, which make contact onto the commutator. They are held into the endbell by a spring and make up the circuit to power the motor.

Can - The large outer part of the motor which houses the magnets.

Capacitor - Typically used on the motor to reduce or remove radio interference / glitching.

Carbon Fibre - A lightweight material found in many top level cars to make the chassis stiff, but light weight in design.

Circlip - Used to prevent components falling off the end of a rod.  This can sometimes be found on a layshaft or hingepin.

Commutator - This is part of the Armature and is made of copper and has 3 segments to it. After time, it will turn a blackish colour from the brush deposits. When a motors performance deteriorates the comm is cut with a lathe to restore its lost power.

Cooling Fan - Used to cool a motor to keep its performance throughout its race, or can also be used on a speed control to prevent it from overheating.

Crystal - these are 27 or 40 MHz in the UK for model car racing and are what plugs into the transmitter and receiver. Newer Spectrum systems do not use these.

Differential - This allows the outside wheel to turn a longer distance than the inner wheel when the car is going through a corner and therefore give the car a better feel through corners. Some cars have solid axles and no differential.

Dogbone - A cheaper, less effective version of the universal driveshaft.

Driveshaft - The part between the axle and the differential outdrive.

Dumped - A term used when the cells in a car are at little or no charge. Usually because they have not been fully charged prior to use, the car has been incorrectly geared or simply over enthusiastic driving with a fast motor.

Electronic Speed control or ESC - This is what takes the power from your battery pack (cells) and regulates how the power is sent to the motor. There are many designs, some only allow the motor to drive forward, others have reverse too. Some also have a limit as to what motor can be used with them.

Endbell - The complete end assembly of a motor which houses the brushes, springs and bearing.

Frequency - See crystal.

Final drive ratio - This is the overall gear ratio of your car that racers refer to when describing the gear ratio they are using to obtain a good overall speed and acceleration from their motor. The FDR is calculated as follows. Spur gear size, divided by Pinion gear size, multiplied by the internal gearbox ratio of the car.

FET - or Field Effect Transistor as it’s known in its full terminology is an item usually found within Electronic Speed Controls to assist in controlling the speed of the car.

FTD or FTQ - Fastest Time of Day, or Fastest Time in Qualifying is what every racer is trying to achieve, to start from position 1 on the grid in the Final race or races.

Gearbox - The transmission assembly within the car.

Glitch - When a car momentarily goes out of control due to radio signals being sent to the car that were not given by the transmitter. Sometimes due to poor installation of the receiver and surrounding electronic items within the car.

Hingepin - Used on the end of the wishbones to either connect the hub to, or to connect the wishbone to the toe block on the chassis.  A bent hingepin will affect the cars handling.

Hood - The part on a motor endbell where the brushes sit in.

Hub - This houses the bearings and driveshaft axle.

Internal gearbox ratio - This describes how many times the transmission turns in relation to 1 turn of the wheels.

Judder - Unwanted movement from the transmission assembly due to unbalanced or worn parts.


Layshaft - Typically found on a belt driven car in the centre of the chassis, which holds the centre drive train components.

Loose - A term used to describe an ill handling car which will spin out mid corner.

Magnet - Found in motor cans to help make the armature spin.

Meshing - The process in which (typically) involves the adjustment between the spur and pinion gear, it is important to allow a small amount of play (or backlash as it can be called) to ensure that gears do not bind. It is equally important there is not too much play between them or the gears will slip and the teeth on the gears will be damaged.

Mechanical Speed Control or MSC - This is what controls the speed of the motor and is used in more basic kits for the newcomer. It is controlled by a servo and although they are ok for starting out, they are rather big and should be replaced with an Electronic Speed Control (ESC) when funds allow.

Neutral Point - The point at which the car is not responding to steering or throttle commands when switched on.

Outdrive - The driveshaft slots into this, the outer part of a differential.

Oversteer - A term used by racers when the car will turn into a corner too abruptly and is difficult to control.

O-ring - Used in shock shafts to ensure smooth operation of the shocks and to assist in prevention of oil leakage from the shock body.

Punch - A word used to describe power, e.g.: "My car has lots of / not enough punch going through the corners".

Propshaft - A centre shaft used to connect the front and rear gearboxes of a car to give it 4 wheel drive.

Pinion Gear - The gear on the end of the motor shaft which determines your final drive ratio. "Bigger" pinion gears with more teeth will give the car more speed, smaller pinion gears will give better acceleration.

Peak - The point where your cells have been charged to their optimum capacity and voltage.

Qualifying race - The timed races before the final race or races of the day to determine which position you will start from on the grid.

Repeak - Charging cells after they have already been charged.

Radio gear - Known as the transmitter and receiver

Receiver - The item which works with your transmitter, it connects to your Electronic Speed control and servo.

RPM - Revolutions Per Minute- The speed at which motor armatures turn. A stock 27 turn motor will typically produce 18,000+rpm.

Spool - This is used instead of a front differential and locks the front wheels to the gearbox. This enables the car to turn into a corner much more aggressively and when used effectively makes for quicker lap times.

Slipper clutch - Used in off road cars to reduce the power output in slippery conditions.

Servo - Connects to the receiver and enables the car to turn car left and right.

Shim - A thin washer used to prevent excessive moment between moving parts.

Spur Gear - The larger gear which is next always to the pinion gear.

Transmitter or Tranny - The handset, which is of steerwheel or stick design, enables you to control the car.

Tuning - The process in which settings are optimised for best possible performance.

Understeer - A term used by racers when the car is not turning into the corner well unless driven at very low speed. Usually caused by incorrect or worn tyres, but can be due to many other factors such as general car setup and available track grip.

Universal Driveshaft - A rebuildable driveshaft incorporating an axle and pin which is able to pivot 360 degrees with suspension movement.

Veer - When a cars steering is not centralised and will turn left or right without any transmitter movement by the racer. Usually occurs when the neutral point of the steering has been incorrectly set when the servo was installed, but can also happen after crashing.

Wishbone - the part between the chassis and the hub, there are typically 4 on an r/c car.





Post a Comment

Please sign in or create an account to post a comment