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.
- Back Plate --The 'cap' that bolts to the back of a nitro engine, sealing it and preventing all of the fuel from pouring out. For engines that use an onboard starting system (pull, shaft, spin, or EZ start), the backplate also houses the one way bearing. Always use a gasket or sensor safe RTV silicone (such as PERMATEX GOLD) to seal the backplate and prevent air leaks.
- Back Pressure íV Plugging Pulse íV Super charging --The percussion (pressure) a pipe or muffler sends back to the combustion chamber of a nitro engine just before the exhaust valve closes. Also known as a ""plugging pulse"" or ""super charging"", back pressure helps to push the fresh air / fuel mixture back inside the combustion chamber instead of allowing it to follow the exhaust gases out. Mufflers provide back pressure, but tuned pipes are optimized to provide the right amount of pressure at the right time (this can be tuned by pipe length or size) - this means more fresh air and fuel in the chamber, better efficiency, and more torque and speed. With tuned pipes, the speed of the returning back pressure can almost reach the speed of sound. The pressure line routes some of this back pressure to the fuel tank to help push the fuel towards the carb.
- Backlash --Refers to the amount of free movement between two gears, specifically, the amount one gear will continue to travel once the other gear has stopped. Also refers to the amount of excess movement caused by play (slop) in an axle assembly.
- Backmarker --Refers to someone that has been lapped (passed by the leader) in a race. Unlike NASCAR, there are no yellow flags or 'lucky dogs' in RC, so once you're backmarked you need to get on the ball or deal with it.
- Backslash - \Slash --This is a popular mod where a TRAXXAS SLASH is converted into a buggy. Basically, this is a SLASH SC truck with a buggy suspension, tires, body, and wing.
- Baffle (Fuel Tank) --A molded-in barrier (or series of barriers) in a fuel tank that reduces the tendency of the fuel to slosh around. Baffles reduce fuel foaming, which can cause an inconsistent engine tune.
- Balance - (1) Armature & Crankshaft --To reduce vibration and improve efficiency, many nitro engine crankshafts and motor armatures are balanced at the factory. This is usually done by adding weight with epoxy resins, or by removing weight by drilling or milling. With crankshafts, drilling or milling is usually preferred since it removes weight, but this alters the magnetic field of armatures, so epoxy is preferred for electrics.
- Balance - (2) Rim & Tire --A tire that is out of balance causes erratic handling and vibration. A tire balancer is commonly used to balance tires, but the front tires on most 2WD models can be balanced on the ride. Either way, just spin the tire and mark the top position where it stops. Spin it again - if the mark stops elsewhere, you're good to go. But if it stops in the same spot, add a little weight inside the rim at the mark and repeat until there is no longer a heavy side. Self adhesive tire weights are available for balancing, but in a pinch, poster putty, chewing gum, or even a folded up dollar bill glued to the rim will work. For tires that are really out of balance, try gluing $20 or even $50 bills to the rim (or better yet, send the bills to rcMart.com and we'll send you a balanced rim).
- Balance Port --A port on lithium based batteries that allows a battery balancer to be plugged into it. This helps to monitor the difference in individual cell voltages. Depending on the intended use or manufacturer, the types of balance ports may vary, which means adapters may be required for the specific balancer to work with various batteries.
- Ball Bearing --A row of small balls or cylinders sandwiched between two rotating rings. Bearings are used to support rotating parts, such as wheels, axles, or driveshafts. They are available in a variety of sizes and styles to suit nearly any application or driving condition. Bearings are infinitely smoother and more efficient than bushings. Keeping your bearings oiled increases their lifespan and efficiency - use specific bearing oil or any light oil (such as 3 in 1).
- Ball Cup --A hollow plastic piece that snaps onto a ball end that provides a pivot point, usually for suspension movement. Using a ball cup/ball end assembly instead of a rigid system allows the car to absorb crash damage, so the ball cup will ""pop off"" instead of break. Ball cups are usually paired with turnbuckles for the ultimate in ease of use and assembly.
- Ball Differential --A differential that uses small balls and pressure rings instead of grease or diff fluid to tune diff action. A basic ball diff consists of; the diff gear, small balls, 2 pressure rings, a tension spring, and an adjustment nut. The balls are inset in the gear and then sandwiched between the pressure rings. As the adjustment nut is tightened against the tension spring, it applies more force to the pressure rings and against the balls, tightening the diff action. Likewise, loosening the adjustment nut loosens the diff, allowing the opposing tires to spin more freely. Ball diffs are known for precise adjustments and smooth operation, as well as being free of backlash or play. Always use light grease or silicone spray to lubricate ball diffs.
- Ball End --A metal ball that has a hex (6-sided) and screw threads on one end. A ball cup will attach over the ball end to provide a pivot point.
- Ball Stud --This is a metal ball with a threaded shaft, used with a ball cup. The ball stud is threaded into a part (or held in place with a nut) and a ball cup is snapped onto it. Most commonly found on suspension and steering linkages.
- Balloon - (1) Battery --Refers to LiPo cells that have swollen or expanded due to over charging or over loading. These batts are done for - dispose of them properly.
- Balloon - (2) TIRES --At extreme speeds or during diff unloading, the rubber tires of a model will expand considerably - this is known as ballooning. Ballooning causes erratic handling and reduced traction.
- Banjo Fitting --A slotted circular clamp used to hold the carb body in place on some nitro engines. A screw or bolt is used in the slot to compress the clamp, which applies the retaining pressure to the carb body.
- Barrel (Shock) Spring --A type of progressive rate shock spring that uses a barrel shape. The transition from the smaller coils on the ends to the larger coils at the center as the spring compresses creates the progressive effect.
- Bashier --No track. No rules. Just drop your ride and peg the throttle. That piece of plywood leaning against the doghouse should make a nice ramp. . .
- Batteries --This is what powers all of the electronics in an RC model, and they are usually grouped into packs designed for specific duties. For RC, alkaline, nickel (NiCad and NiMH), and lithium (LiPo, LiMN, and LIon) batteries are most commonly used. With the exception of alkaline, RC batteries are rechargeable.
- Battery Bar --A short piece of metal (usually a copper compound) that is soldered between individual cells (batteries) to form a battery pack. Battery bars are waaay more efficient that the 'foil plated cardboard' commonly used for factory assembled packs, as well as offering rigidity to the finished assembly.
- Battery Box --A case on nitro models designed to hold the receiver pack. On most models, this is found near the center line of the chassis, but on 2WD stadium trucks, it usually 'hangs' off the rear.
- Battery Brace --A narrow plate that is placed on top of a battery pack to hold it in place. The battery brace is usually held down with body clips or thumbscrews.
- Battery Jig --A tool used to hold individual batteries (cells) in place while building battery packs. Most battery jigs are designed for 4 to 6 cells.
- Battery Pack --A collection of batteries that are joined together to combine the voltage of the batteries to power an electrical device. This term is used for electric RC cars (normally a pack to power the motor) and also for Nitro cars (to power the servos controlling steering and throttle/brake).
- Battery Slots --A series of thin rectangles cut into the chassis of an electric model. The batteries sit inside these slots so that the batteries are flush with the underside of the chassis. This lowers the CG of the model. Along with a battery brace, battery slots also keep the batteries from shifting forward, backward, or side to side. It is a common practice to file (bevel) the edges of the battery slots to lower the batteries even further and to reduce rubbing on the battery casings. Battery slots are designed to be used with hand built battery packs (not stick or shotgun packs).
- Battery Strap --A belt used in place of a battery brace to hold the batteries in place on electric powered models. This belt secures the batteries with a velcro or buckle closure. Strapping tape also acts as a battery strap.
- Battery Tray --A flat 'platform' used as a base for mounting battery packs. The battery packs are usually secured with zip ties, velcro, or servo tape. Battery trays are commonly found on TVP (Twin Vertical Plate) style models, and may be a stressed part of the chassis.
- Bead Rings - Bead Lock Rings --The flat, circular rings attached to the outside of bead lock rims to hold the tire in place. These clamp (lock) the tire bead to the rim. Some people use only every other screw in a bead lock ring to reduce rotating mass.
- Bearing --A hollow metal ""donut"" that uses balls inside to increase the efficiency of a rotating shaft (like an axle). Highly recommended as the first option part for any kit equipped with bushings, bearings have become a standard accessory in most RC kits today.
- Bearing Puller --A "screw and plug" type of tool used to efficiently remove bearings from electric motors without damaging the bearing or mounting surface.
- Bearing Seal -- Bearing Shield -A 'washer' that rides between the bearing races, designed to pretect the bearing balls from contamination, or to prevent oils or pressure from passing through the bearing. Not all bearings are sealed (or shielded). Bearing seals come in 3 basic styles:
(1) METAL - Metal bearing shields offer the least seal protection, but spin more freely compared to other seals. These are commonly found in drivetrain components, such as hub carriers, where protection from dirt and debris is needed but reduced friction is desired.
(2) RUBBER - This offers the best seal of all bearing shields, but increases friction and drag in the bearing. Rubber sealed bearings are commonly found supporting the crank journal in nitro engines (a.k.a. front bearings). Here, they help prevent pressure and fuel from exiting the crankcase through the bearing.
(3) TEFLON - Teflon is the all around bearing shield - striking a compromise between the sealing ability of rubber and the free spinning ability of metal shields. Teflon shielded bearings may be found anywhere that a shielded bearing is needed.
- Bellcrank --The type of steering mechanism most common in RC cars, trucks and buggies. It consists of two posts, one of which has a connection to the steering servo. This connection turns one of the steering arms, which is connected with an Ackerman link to a second steering arm. The left side steering arm is connected to the left steering knuckle with a turnbuckle, just as the right steering arm is connected to the right steering knuckle. Some bellcrank systems allow racers to alter the Ackerman angle, which can tune the steering effect of the steering system in different ways.
- Big Block --In RC terms, this refers to a .21 engine or a .15 engine that uses a .21 engine case.
- Big Bore Shock --Used on some off road models, this type of shock has a stock length shock body - but the bore (diameter) has been increased. The increased bore allows more shock oil to be used, resulting in smoother shock action, but marginally increasing weight. Of course, big bore shocks use larger diameter shock springs than common stock shock
- Bled --After correctly assembling a shock absorber with no excess oil and no air bubbles, that shock absorber is considered properly ""bled"". "
- Bleeding (1) - Paint --Refers to paint seeping under the masking when painting. This is usually caused by air bubbles in the masking medium, masking tape not being pressed down around the edges, contamination of the masking medium (such as oils or dirt), or applying paint in excessively heavy coats.
- Bleeding (2) íV Shocks --Refers to removing excess shock oil from the shocks during building. This is usually done by gently snugging the shock cap, compressing the shock shaft until the shock end touches the shock body (during this, excess oil should leak out around the cap), then fully tightening the shock cap. Ideally, the shaft should rebound to about 1/8 of it's total travel (without shock springs) once released. Make sure all shocks rebound equally (this can be checked with a shock matching tool or by measuring) to ensure your model isn't tweaked. Adjustments to the rebound length can be made by repeated bleeding (if the rebound is excessively off), or by screwing the shock end in or out on the shaft to make minor adjustments. Different types of shocks, such as: top load, bottom load, emulsion, and reservoir shocks may require different bleeding styles - check the manufacturers' guide for proper bleeding.
- Blow Hole --A hole or series of holes drilled into a rim or rubber tire to allow air to enter and exit the tire carcass as it expands and contracts. This allows the tire and foam to react efficiently.
- Blow Out --This happens when the pressure inside a case exceeds the ability of the case or seals to hold it. Shocks may blow out after extreme jumps by busting the seals, and diff cases may blow out in high powered / high traction situations.
- Body - Lid íV Shell --Refers to a models' outer body, which is usually made of vaccuformed lexan or polycarbonate plastic. Bodies are available in many different styles and sizes to fit any model, and is usually one of the first things customized on a ride. Most bodies are pulled (vaccuformed) from clear Lexan and painted on the inside. These bodies are usually available in a variety of thicknesses, with .10, .20, .30, .40, and .60 mm being the most common. The thicker bodies (such as .40 and .60) are heavier, but more durable - while the thinner bodies (such as .10 and .20) are lighter, but less durable.
- Body --In RC terms, the body is the thin, (usually) clear plastic piece that covers the car and provides the ""shape"" of the car. Most bodies, especially on touring cars and some other vehicles, are easily interchangeable, so it's possible to run a street truck body, then change it for a sedan body, then change that for a coupe body.
- Body Clip - R Clip --The 'R' shaped pin that is inserted through the body post to hold the body in place. Body clips are also used on battery braces and wings, among other things.
- Body Post Markers --These are basically sharp cones that are slid onto the body posts to help find the location for the body post holes on painted lexan bodies. The body is centered over the cones in the desired position then pressed down - the markers dimple the body where the holes need to be drilled. Of course, the same effect can be had by placing a spot of paint or oil on the body posts, but the markers tend to be easier to deal with and more accurate. For the ultimate in techno-geek nirvana, there are even LED body post markers that slide over the body post and shine a light through the body. These markers plug into the model's RX, so once the body is mounted, you could even mount them on your ride as tail lights.
- Body Reamer --A sharp, tapered tool used to cut small holes, such as body post holes or cooling holes, in lexan bodies and soft plastics. Some reamers are tapered, while others may be 'stepped' in millimeter or fractions of an inch increments.
- Body Roll --Refers to a model's tendency to lean while cornering - the tires remain level, but the chassis (and body) lean in the opposite direction of the corner. All rides will exhibit some amount of body roll, but it is more pronounced with higher, off road models. Excessive body roll may be a sign of shock settings that are too soft for the current driving conditions.
- Body Savers --Self adhesive foam 'washers' that are applied to the inside of lexan bodies over the body post holes. These prevent the body posts from wearing (scratching) the paint and keeps the body from rattling. Use the 'donut' holes and excess foam to help pad electronics or batteries.
- Bottom Out - (1) Model Clearence --When a models suspension is compressed far enough for the chassis to scrape the ground, it is known as 'bottoming out'.
- Bottom Out - (2) Needle Valve --Refers to the point where a needle valve is fully closed and cannot be turned any further. Critical settings are expressed as a number of turns out from the bottomed out position, such as 3 1/2 turns out. When bottoming out a needle valve, it is important to stop as soon as resistance is felt, since closing the valve any further could damage the O ring seal.
- Brake --The system used to slow a car or bring it to a stop. In an electric car, the electronic speed control performs this function. In a nitro car, braking is normally provided by a disc brake and brake pads.
- Brake Check --A driving tactic that is used to disturb a racer's concentration. A car that is being followed closely by another car can abruptly slow down in a section of the track where braking normally doesn't occur, causing the following car and other cars to swerve to avoid the car in front. Sometimes this works, sometimes it doesn't!
- Brake Disc - Brake Rotor --Refers to the rotating disc of a nitro model's brake system that the calipers squeeze to slow or stop the model. Rotors are commonly drilled, slotted, or vented (an open, vaned type of system sandwiched by 2 discs) to help dissipate heat.
- Brake Fade --A term used when a car's brakes heat up and provide less stopping power, forcing the driver to learn to brake earlier as a long race progresses. Upgrading to our Fiber Brake Disk will prevent brake fade for racers. Drilled brake disks look really cool, but we are not aware of any actual performance advantages they may have.
- Braking --Usually used in sentences like ""under braking"" or ""need more/less braking"", this simply refers to the time when the car is actually using its brakes.
- Braking Zone --The area of a track where cars are slowing down to approach a corner. Easiest to find at the end of a straight section. A track can have many braking zones.
- Break Out --A drag racing term that refers to a model completing the run in a quicker time than predicted during a bracket (handicap) race. A break out usually results in a race loss unless the opponent crosses the center line or red lights.
- Break-In --The process of running a nitro powered engine at idle speeds to prepare it for general use. The generally accepted method is to run the engine very rich (the exact needle valve adjustment will vary from engine to engine) for at least 3-4 tanks while the car is on a car stand. Running a fan over the engine and varying the idle speed slightly during break-in is also generally accepted. NOTE: As the engine breaks in, the speeds will pick up and you may have to richen the air/fuel mixture slightly. An engine isn't fully broken-in until it has run about 10-15 tanks, at which point you will see its full potential.
- Brush --The small alloy 'block' attached to the end of a brush shunt. Brushes are usually made from a copper (soft) or a high silver content (hard) alloy, and they slide into the brush hoods on a brushed electric motor. The brush is what makes contact with the comm, transferring power from the battery to the motor (via the speed controller). Brushes are available in many styles (such as square, rectangle, round, and octagon), and often come with serrations or grooves cut into the contact face, affecting their resistance and power distribution. Larger brushes (more face area) transmit more voltage, but may cause shorting if they are too big. Smaller brushes transmit less voltage, but help reduce arcing. A brush spring presses against the back of the brush to hold it against the comm. In some cases, such as with micro motors and closed endbell (cheapie) motors, the brushes may be copper strips or 'fingers' that are not replaceable. The following represents common RC brush shapes and alignments :
LAYDOWN - This is a rectangular brush that is wider than it is tall. Good for low end and mid range power, but may produce arcing (reduced power) at high RPMs. Laydown brushes are the RC car standard.
OCTAGON - A good compromise between square and round brushes - an octagon brush can provide some of the benifits of a round brush on any motor that uses square brushes.
ROUND - Commonly used in 'V' endbells, round brushes offer great mid-range power with reduced arcing at high RPMs.
SQUARE - An all around brush meant to offer the best between power and torque.
STAND UP - This brush is taller than it is wide, basically a brush laid on it's side. This may reduce low end torque (as well as reducing arcing) but increases top end potential power.
- Brush Face --This is the side of the brush that makes contact with the comm (commutator). The brush face is often serrated, slotted, or grooved to alter current transfer and brush performance.
- Brush Hood --The part of a motor's endbell that houses the brushes, keeping them aligned to the comm. Depending on the endbell design, the brush hood may be arranged to hold the brushes in a stand up, lay down, or V configuration. Brush hoods may be squared (for stand up or lay down brushes) or rounded (for round brushes). For optimal performance, the brush hoods need to be in alignment with the comm - this can be achieved with the use of a brush hood alignment tool. The industry standard material for brush hoods is copper due to it's increased conductivity.
- Brush Hood Alignment Tool --This is basically a square 'stick' that is pressed into both brush hoods on the endbell to align them with the comm.
- Brush Hop --The tendency of electric motor brushes to bounce (hop) at high RPMs, causing the brushes to loose contact with the comm. This causes arcing and increased heat, which robs power. Truing the comm or installing stiffer brush springs help to eliminate brush hop.
- Brush Shunt --A flexible, braided wire that connects the brush to the positive or negative side of a motor's endbell. The shunt is usually connected to the brush at the factory, and is soldered or screwed to the endbell. Some brushes even use double (2) shunts to help move more current.
- Brush Spring --The spring found on a motor endbell that holds the brush against the comm. Brush springs are offered in a variety of rates (stiffness) to fine tune the power output of the motor. Basically, lighter springs = less pressure on the comm and higher RPMs, while heavier springs = more pressure on the comm and higher torque. Using a softer spring on the negative (-) side of the motor increases comm life without a loss of performance.
- Brushed Motor --An electric motor that uses brushes to transfer battery power to the comm, which energizes coils of wire wrapped around an armature. This creates a magnetic field that 'pushes' against fixed magnets mounted in the motor can, causing the armature to rotate as needed. After every 180* of rotation, the polarity is reversed. Brushed motors are available in a variety of sizes, and are usually rated by turn and wind, such as 10x4 (10 turns, 4 winds - or 10 quad). Brushed motors may also be rated as stock or modified, as well as machine wound or hand wound. Brushed motors commonly temp at about 200* to 240* after a good full run. If the motor is running hotter, it may be overgeared - try dropping a few teeth on the pinion gear. Some brushless ESC's can also run brushed motors - when using this kind of set up, always make sure you install the correct capacitors on the motor. Also See - MOTOR CONVERSION
- Brushless Motor --First introduced in 1962, it took brushless technology a long time to reach the RC car market. These electric motors have stationary wire coils mounted on the inside of the motor can. A rotor (i.e. magnet) spins in the center of these coils. The coils are energized in sequence by the ESC, creating a magnetic field that 'pushes' the rotor, causing it to rotate as needed. Since the coils are stationary, this eliminates the need for brushes to transfer power to a rotating part (as the brushes transfer power to the comm in a brushed motor), hence the name 'brushless'. Brushless motors tend to be more efficient, quieter, smoother, and more powerful than brushed motors, as well as requiring virtually no maintenance. Compared to brushed motors, brushless motors excell at low to medium load applications, but are comparable at high load applications (such as crawling or pulling). However, cogging may be more evident with brushless motors at low speeds. They have a higher power band than brushed motors, so try gearing down a few teeth on the pinion (i.e. go from a 16T pinion to a 14T pinion) than you would with an equivelent brushed motor. A brushless motor reduces EMI (ElectroMagnetic Interference) compared to brushed motors, wich helps reduce glitching. Brushless motors are available in a variety of sizes, and are rated in 1/2 turns (6.5, 7.5, 8.5, ect) or kv (kilovolt), such as 2200 kv or 4200 kv. They come in 2 basic flavors - sensored or sensorless. Brushless motors are 3 phase motors (the A, B, and C wires are each connected to one of the 3 coils (phases) inside the can). Each phase makes up 120* of the 360* of rotation. Most brushless motors run happily at a temperature around 150* to 170*. Never run a schottky diode with a brushless motor (just in case you're wondering). Also See - MOTOR CONVERSION
- Buggy --Among the more popular types of RC cars, buggies are durable cars that can run on most surfaces. The most popular are rear-motor two-wheel drive (2WD) electric buggies, but four-wheel drive (4WD) nitro and electric buggies are popular also.
- Bulkhead --A part of the car that is generally connects to the chassis. During assembly, other parts are connected to the bulkhead, making the bulkhead one of the primary foundation pieces of the car.
- Bump Box (Electric) --A device, such as a charger?and battery pack configuration, used to quickly 'top off' the batteries of an electric ride just before a race. This eliminates any loss of voltage since the last charge, ensuring maximum punch off the line.
- Bump Handling --Refers to the response characteristics of a model while navigating bumps and rollers.
- Bump Start - (1) Engine --Refers to a nitro engine that requires a starter box to be started. This type of engine offers lower weight and less rotating mass, but you must always have a glow driver and starter box (with batteries) handy to start it.
- Bump Start - (2) Starting --Refers to starting a nitro engine with the use of a starter box.
- Bump Steer --A condition caused by steering linkage or suspension geometry, causing the steering angle to move due to suspension compression, altering the model's heading. Bump steer may be caused by a steering bellcrank or servo that doesn't match the angle of the hinge pin or king pin, unequal upper and lower suspension arm lengths, or a turnbuckle or tie rod that is at a different height inboard (such as at the ackerman link) than outboard (at the hub). Keeping all steering linkages at 90* to each other also helps eliminate bump steer. Increased bump steer may help a model recover after jumps, but too much will make it seem 'twitchy' in the corners, especially on rough tracks. Bump steer can be adjusted by raising or lowering the mounting location of the steering links on the steering arms with the use of spacers.
- Bushing --A metal ""donut"" that supports a rotating shaft (like an axle). Most bushings are metal, with most metal bushings made out of something called Bronze Oilite. This is a metal that is permanently lubricated.
- Button Head Screw --A screw with a convex rounded head, usually used in moderate torque applications or where clearance is an issue.
- Bypass Channel --A passage way, or 'tunnel', between the engine block and sleeve of a nitro engine. Bypass channels transfer the air / fuel mixture from the crankcase to the transfer ports.