New to the RC Hobbies? What does buggy, bulkhead, nitro mean in radio control car hobbies? Check out the glossary for remote control cars below.
- Mabuchi (Motor) --MABUCHI is a motor manufacturer that makes the closed endbell motor that is common in many budget RTR rides, A.K.A. the MABUCHI 540 RS, or Johnson 540. MABUCHI has become synonymous with stock, closed endbell, silver can motors.
- Machine Wound Armature --As the name implies, this refers to a brushless motor's armature that has had the coils wound on by a machine at the factory. Machine wound motors are cheaper than those with hand wound armatures, but have lower efficiency.
- Magnet --This usually refers to the magnetic 'blocks' inside the can of a brushed electric motor. These magnets provide the magnetic field needed to propel the armature when electricity is introduced. Most brushed motors use wet pressed magnets, which are chemically bonded magnetic particles. High end electric motors may use cobalt or NEO rare earth magnets. The common brushed motor has 2 to 3 magnets in the can. For brushless motors, the magnet is usually referred to as the rotor.
- mAh íV Milliamp Hour --An abbreviation for milliamp hour, a technical term that shows how long a given power source (like a battery) can give off power. The mAh is usually displayed prominently on the pack or individual cell, such as 4800, meaning the pack has a capacity of 4800 mAh. This is the load the battery can sustain for 1 hour before being exhausted. Divide the mAh by 1,000 to find how many amps the battery can maintain for 1 hour (4800 / 1000 = 4.8 amps for 1 hour).
- Main# or Main Event --"In RC car racing terms, this refers to the final race of the day in each class you are entered in. See Qualifier, then read the rest of this definition.
Right after all the qualifying races are over, the race computer will sort all the racers, with the 10 fastest racers in the """"A Main"""", the next 10 fastest in the """"B Main"""", and so on. The number of racers in each main may vary, depending on the number of total racers in the class. Each main event is run in order from the """"highest"""" letter to the """"lowest"""". For example, if there are enough racers to make an E Main, the E Main is run first, then the D, the C, the B, the A, etc. The winner of the A Main is the winner for that class.
Large events (National and World Championships) will usually have what are called """"Triple A Mains"""". This is only for the top ten racers in each class, and they will all run three main events. In this case, your two best finishes count towards the final score, so if you win two races in the Triple A Main, you would be crowned the champion."
- Matched Cells --Individual cell sets grouped together at the factory according to similar capacities and voltages - eliminating any 'weak links' in the set. Matched cells generally use the top rated cells, resulting in the highest quality . . . and price.
- Mesh - Play --The distance between two interlocking gears, such as the pinion gear and spur gear. To set the proper mesh, you want just a 'tick' of movement (or play) between the gears - this allows them to operate smoothly without binding. A common trick is to insert a piece of notebook paper between the gears, then push them together while tightening any mounting screws. Remove the paper and you should have perfect mesh. A mesh that is too tight will cause excess drag and undue stress on the bearings, while a mesh that is too loose will result in stripped gears.
- MG (Metal Gear) SERVO --Refers to a servo that uses metal gears to increase durability and prevent gear stripping (a common occurrence with servos used for steering or other high load applications). These metal gears are usually titanium or karbonite to reduce weight. Even though the servo is designated as metal gear, it will almost always have a plastic or delrin idler gear to help absorb impacts.
- Micro - MINI --This usually refers to RC models that are 1:14 scale or smaller (1:14, 1:16, 1:18, 1:124, 1:32, 1:64, ect.).
- Micro Switch (Speed Control) --A speed control that has 2 basic settings; stop and go (WFO). Micro switches are commonly used for high traction drag racing applications. A microswitch may be an electrical unit, or a micro servo that operates a physical switch - either way, a micro switch instantly sends all of the battery's available voltage directly to the motor.
- Mid Case --The main section, or 'box-like' center of a servo case. This is sandwiched between the upper and lower parts of the servo case, which are pulled tight against it with long servo screws.
- Mid-Narrow --see width, wheel
- Milliamp --A rating given to batteries, generally the higher the milliamp rating, the longer the cell can provide power. Currently, batteries are available for RC use that range from 1500 to 3000 milliamps.
- Mini --"From the Morris Mini Cooper, """"Mini"""" refers to an RC car that is roughly 1/10 scale but models a very small real-life car like the Mini Cooper or the DaimlerChrysler A-Class. The general difference between a Mini car and a regular sedan car is that the wheels, tires, body, suspension arms and chassis are smaller. For cost-saving measures the rest of the parts are generally interchangeable, especially the drivetrain, bulkheads and shock towers."
- Minimum Brake --The percent of full brake applied by an ESC at it's lightest possible braking force - this is usually around 15%.
- Minimum Drive --The percent of full throttle applied by an ESC at it's slowest possible speed - this is usually around 3%.
- Mixing (SERVO) --Servo mixing is a feature available on some high end radios that allows input from the transmitter (such as brake) to control 2 servos on separate channels independently. Thus a model with front front and rear brakes controlled by independent servos (such as a 1/4 scale model) can be programmed to apply 60% brake to the front and 40% brake to the rear. Also, a model can be programmed to turn full right whenever the throttle is applied (if you are the adventurous type) by mixing the throttle and steering servos.
- MOA --Abbreviation for MOTOR ON AXLE
- MODEL (NAME) --A lot can be determined by many model names. At first glance, some names may seem cryptic (such as an NT10), but if you look a little closer, you may realize what it means (a 1:10 scale nitro truck). Below is a listing of the most common letters and numbers used in model names, along with their usual meanings:
B íV BUGGY
E íV ELECTRIC
F íV FACTORY
N íV NITRO
R íV RACE
T íV TRUCK
5 íV 1:5 SCALE
8 íV 1:8 SCALE
- Modified Motor --A low turn (such as 12T or less) brushed motor with adjustable timing and rebuildable parts. Modified motors are usually offered with machine wound or hand wound armatures.
- Module íV Metric Pitch --A metric ratio of a gear's diameter to the number of teeth (a 50mm gear with 50 teeth would be 1 module). Module ratings are rare in RC, and are most commonly found on European kits or parts. Module gears shouldn't be used with gears rated by standard pitch. 48P = 0.6 module (42.3P), 64P = 0.4 module.
- Molded Inner Foam --A form of tire insert that is molded in a special mold instead of cut out of foam sheets. While more expensive, the molded inner foam stays in place on the wheel and does not move side to side as the car goes through cornering forces.
- Molded Insert --This is a foam insert that has been shaped to fit the rounded contours of the tire carcass. Molded inserts provide more consistent handling and less sidewall flex, but add rotating mass.
- MOLEX PLUG --See TAMIYA CONNECTOR
- Monocoque (Chassis) --Some RC car chassis are monocoque, meaning they are a 1 piece chassis without the need for additional chassis braces or top decks. Monocoque chassis are either molded, machined, or stamped in complex shapes to ensure rigidity and reduce chassis flex.
- Mosfet - Metal Oxide Semiconductor Field Effect Transistor --A voltage controlled power device that can handle high electrical currents. MOSFETS are used in high end electronics such as radios, receivers, servos, and ESCs, and allow these devices to be made more compact without the loss of efficiency or current capabilities.
- Motor (Reference) --Brushed Motor, Brushless Motor, Closed Endbell Motor, Coreless Motor, Mabuchi (Motor), Motor, Motor Conversion, Parallel (Motor Wiring), Sensored (Brushless) Motor, Sensorless (Brushless) Motor, Series (Motor Wiring), SERVO Motor.
- Motor --In RC racing this generally refers to an electric motor. RC motors are Direct Current (DC). Motors come in various sizes for different scale applications (such as 380 or 540), and are commonly available as coreless, brushed, or brushless. All motors use energized wires (coils) and magnets to turn the rotor or armature. The first DC electric motor was introduced by Anyos Jedlik in 1827, but it wasn't until 1855 that he thought to actually put it in an electric powered model (and even then, he never thought to make the thing radio controlled).
- Motor Can --This is the cylindrical case (can) that holds all of an electric motor's internal components (such as the armature or rotor, magnets, and coils). Thicker cans reduce magnetic loss but increase weight. For brushed motors, you will also find vents (cooling holes) in the can - the size and position of these holes also affect magnetic loss. For brushless motors, the can is usually machined from aluminum, and commonly uses fins (heat sinks) instead of vents to reduce motor temperature.
- Motor Conversion --There is no hard and fast rule for converting between motors (i.e. brushless vs. kv vs. watts vs. brushed). All motors can be built differently, and even 2 13.5 brushless motors built by the same company can have drastically different kv and watt ratings depending on the purpose they were built for. Still, it is possible to get a fairly accurate estimate of how motors that are rated differently compare to each other (such as what turn a 3,300kv motor is equivalent to). The following tables are an estimate of motor comparisons - and should be taken with a grain of salt:
- Motor Limit --Many ESC's have a motor limit, which refers to the lowest turn motor it can handle (such as 19T limit). This is basically a guideline, but the farther you stray from the motor limit, the increased chances that the ESC will overheat or even become fried. In general, you don't want to stray more than 1 or 2 turns from the limit.
- Motor on Axle íV MOA --A term used to describe dual motor rock crawlers that have an electric motor mounted directly to each axle. This offers a lower CG and a more compact drivetrain than shaft driven crawlers.
- Motor Plate --This is the part that the motor is bolted to on an electric powered model. The motor plate is commonly a machined or stamped aluminum plate that is bolted directly to the model's chassis, rear pod (such as on pan cars), or tranny case (as with most 3 gear 2WD trucks). Note that nearly all motor pods are designed to hold a certain sized motor, so you might want to check before bolting that 550 sized powerplant into your 1:18 scale ride.
- Motor Pod --See Rear Pod
- Motor Screws --The screws that attach an electric motor to the motor mount. The threads on these screws may be slightly different that the threads on the rest of the screws used on the model, so motor screws often have serrated edges on their heads for quick identification.
- Motor Shaft --Refers to the portion of an electric motor's armature that supports the pinion gear.
- Motor Sham --An absorbent fabric tube that is soaked in cold water then slipped over or wrapped around an electric motor to help keep it cool.
- Motor Shims --Super thin 'washers' used to center a motor's armature in the can's magnetic field. These shims are placed between the bearings and armature of an electric motor to ensure the armature spins freely. To properly center an armature using motor shims, first spin the armature by hand without the brushes or springs installed - this centers it inside the can. Then pull on the armature, if there is more than just a 'tick' of play, a shim, or shims, will need to be added to that side. Disassemble the motor and add the estimated number of shims. Reassemble the motor and repeat, but this time pull on the armature, adding any shims if necessary. The goal is to achieve a 'tick' of play in each direction. Always use at least 1 motor shim on each side. Shimming a motor may not offer insane power gains, but every little bit helps, especially with stock racing.
- Motor Spacer --A plate or washers placed between a motor and the motor mount to help align the pinion and spur gears.
- Motor Spray --A pressurized cleaner that evaporates quickly and leaves no residue, which is perfect for electrical parts (such as motors). Motor spray is basically designed to clean the comm of brushed motors by spraying it into the motor can vents.
- Motor Stand --An external motor mount used to break in, tune, or work on an electric motor before the motor is installed in the model.
- Motor Timing --See TIMING (MOTOR)
- MSC - Mechanical Speed Control --Your grandma's ESC. An MSC is a speed controller that uses a servo to move a conductive arm across resistors to transfer power from the battery to the motor. Highly inefficient and heavy, an MSC would look archaic in today's rides (and make you think something was terribly wrong with your EXPO settings). But, back in the day it was neato-keen. As much time was spent cleaning and greasing an MSC as most people spend rebuilding shocks today. Still, try to find a clean MSC on E-Bay, and you're likely to spend twice what you would for a modern ESC (go figure).
- Mud Guard --Mud guards are used on narrow chassis off road models (such as buggies and truggies) to extend the sides of the chassis, filling the space between the sides of the body and the chassis edge to help prevent dirt and debris (and mud) from reaching the chassis components. These are usually plastic, tub like parts that are bolted to the chassis. Also, this may refer to an upright shield bolted to the front of the lower suspension arm that helps prevent mud from caking on the suspension arm and adding unsprung weight.
- Muffler --Installed on every Nitro-powered car, the muffler system traps exhaust gases from the engine case and provide pressure to the fuel tank while keeping noise levels to a minimum. Tuned pipes are another type of exhaust system that provide more power than a muffler.