Electric Skateboard Glossary of Terms
ABEC – Annular Bearing Engineers’ Committee. ABEC is an American method for rating the accuracy and precision of bearings. The standards used is governed by the ABMA (American Bearing Manufacturers Association). It is a scale from 1 to 9, and only consists of odd numbers. In terms of cost, ABEC 1 bearings are the cheapest and ABEC 9 are the most expensive (can be hundreds of dollars for one bearing). In the world of skateboarding, bearings are the circular metal rings that fit inside the hub of the wheels and are the same size. Each wheel has two bearings with a spacer in between them. The more precise the bearing, the more smoother and faster the wheels turn. Cheap skateboards use ABEC 3, most use ABEC 5, and very high end ones use ABEC 7. The rating is determined by four factors: 1) Bore accuracy, 2) outside diameter, 3) width, and 4) rotating accuracy. All accuracies are measured in microns (one millionth of a meter). Although ABEC is American, there is also an international rating (ISO – International Standards Organization) system as well. ABEC 1 = ISO Normal, ABEC 3 = ISO Class 6, ABEC 5 = ISO Class 5, ABEC 7 = ISO Class 4, ABEC 9 = ISO Class 2. Note that there are wheels labeled ABEC11. In this case, it is not a rating designation, but the name of the company.
ASTM 1492 - ASTM (American Society for Testing and Materials). The ASTM 1492 specification applies to helmets used for bicyclists, skateboarders, and trick roller skaters. A proper helmet should be certified to this standard which includes the ability to protect against multiple impacts.
AWD – All Wheel Drive. An electric skateboard with 4 motors, one for each wheel.
Baseplate - The flat part of the truck which is screwed to the skateboard.
BLDC – Brushless Direct Current. This refers to the type of motor used by all electric skateboards, whether it is hub or belt drive. When paired with a VESC, the definition is applied in conjunction with a tool used to setup the controller. Note that as there are different flavors of VESCs, there are different versions of the BLDC tool as well. To pair the right VESC version with the right BLDC tool version, the firmware versions of the VESC and BLDC tool must match. A more recent tool, VESC tool, is much more flexible with a more friendly user interface, and will have the ability to update firmware. Only drawback currently is that it will not run on Mac OS, (only Linux, Windows, and Android).
Image from diyelectricskateboard.com
BMS – Battery Management System. A circuit board which interfaces with the Lithium battery packs for charging cells evenly.
Bushings - A pair of urethane rings which wrap below the end of the kingpin and above the other end to facilitate the turning of the skateboard when carving. They come in two basic shapes: Barrel and Cone. Although these are little guys, their placement and combination used will impact the performance of the skateboard.
Deck – The board where you stand which are usually constructed of various woods or carbon fiber materials.
DIY – Do-It-Yourself. There is a vast community of electric skateboarders who like to custom build their own boards.
Dual Drive – An electric skateboard with two mounted motors, usually placed to power each of the rear wheels. A less seldom configuration is one at the front and the other at the back diagonally to the front wheel with the first motor.
Enclosure – also known as components housing. The enclosure houses the board’s electronics components (battery, ESC, etc..) and is usually attached underneath the board. Usually the enclosure is made of plastic (sprayed with a protective coating) or a light metal, and is attached using screws, strong glue, or strong tape.
ESC – Electronic Speed Controller. This is the control center of an electric skateboard. In other words, the ESC is the smart interface between the skateboard’s motor and its batteries. It supplies the appropriate voltages and amps to control the motor’s speed, direction, and braking among other management functions. For electric skateboards, the two choices of ESCs are ones built for hobby car’s and the Vedder ESC (VESC).
Grip – The part of the surface of the board which you stand on to provide traction to prevent you from sliding or slipping off the board.
Hangar - The elongated part of the truck that holds the axle for the wheels.
Indiegogo – one of two major fund (see kickstarter) raising platforms used by many electric skateboard startups. Indiegogo is less known, but more widely used by electric skateboard startups due to its greater flexibility. There is no approval process and anyone can start a campaign as long as a bank account is provided. Two fund raising options are provided: a) flexible which allows the project to keep the funds even if the target amount is not met, or b) fixed which means that funds must be returned if the target amount is not met. Indiego charges 4 percent if the target amount is met and 9 percent if the target amount is not reached. Companies who have used Indiegogo include Acton, Huger, and Riptide.
IPxy - IP stands for Ingress Protection. It is a rating consisting of the two digits after the IP. The first digit denotes the degree of solids protection and the second digit denotes the degree of liquids protection. Some of the manufacturers commonly state the enclosure (containing the batteries and controllers) is IP65, 6 is the highest rating which means it is dust tight and 5 means water projected by a nozzle (6.3mm) against enclosure from any direction shall have no harmful effects (8 is the highest which means the object is protected from water when immersed under 1 m). So IP65 means the enclosure is protected from 100% dust ingress and low water jets from any direction.
Kickstarter – one of two major fund (see Indiegogo) raising platforms used by many electric skateboard startups. Kickstarter is more known, but has more limitations. All projects must be approved by Kickstarter and they have stricter requirements (residents of certain countries, age 18 and over, etc…). Kickstarter retains 5 percent of the funds raised and also charges 3-5 percent payment processing fee. Every fund-raising campaign must have a target amount and if it is not reached, existing backers will not be charged and the campaign creator will not receive any funds. Notable companies who have used kickstarter include Zboard and Marbel.
Kingpin – a metal bolt (usually about 2.5" in (6.4 cm) length and 3/8" (.95 cm) diameter) which connects the truck's hangar to the baseplate. It is paired with a kingpin nut with a pair of bushings in between the bolt and the nut. The combination used will significantly impact the board's controllability and speed.
Kv – rating of a brushless DC motor expressed as rpm (revolutions per minute) per volt. The higher the Kv, the less torque and vice-versa.
LiPo – Lithium Polymer. LiPo batteries (vs Lithium Ion) are used by many people who build their own electric boards. They are cheaper but can be more volatile (greater risk of catching fire or even exploding) than Lithium Ion batteries. Furthermore, they have a shorter life (300-400 charge cycles on average vs 1000-1500 charges for Lithium Ion). As long as you use properly charge it (using a balance charger) and maintain operation within its specification ranges, LiPo batteries should be relatively safe. The batteries are light and they work well with many of the electrical components used by skateboard do-it-yourself builders.
Li-Ion – Lithium Ion. Li-Ion batteries – used mainly by many mid-range and high-end skateboards. They last 2-3 times longer than LiPo batteries. Battery technology is not simple and there are advantages with both types of batteries. Numerous perspectives exists on how to organize the cells in each battery type to yield the optimal discharge curve. The basic principle is to maintain a near constant voltage discharge when powering the skateboard. To maximize the life of the battery, it should be not be fully discharged - once the discharge reduces to a cutoff value (3.0 V per cell in Lithium batteries), then it should stop supplying power. At this time, Lithium-Ion batteries for electric skateboards are not as prevalent as LiPo batteries and are much more expensive.
Li-FePO4 – Lithium Iron. Third type of electric skateboard battery emerging in the market. Only known board which utilizes it is the Boosted Board. It is safer and lasts longer than LiPo batteries, but much more expensive and not easy to source.
LiPo Battery
Li-Ion Batteries
Motor Part Number - Usually in the form of a four digit number, “xxyy”, where “xx” specifies the diameter of the motor in mm and “yy” specifies the length of the motor in mm.
RC – Remote Control. The main mechanism (usually handheld) used by most electric skateboarders to control the movement (i.e. acceleration, braking, etc…) of the board. Fancier ones can also be used to help guide the user to an intended destination in conjunction with a mobile application.
Regenerative Braking – Capability found in many electric skateboards when means that your battery is charging as you are braking. For do-it-yourself skateboard builders, the capability can be configured using the BLDC tool with a VESC.
Trucks - T-shaped pieces (comes in a pair) which attaches the wheel to the skateboard. Each truck contains an axle, a kingpin, and two bushings. The bushings. made of urethane, fit under and over the kingpin. to facilitate the turning of the skateboard when carving.
VESC® - Vedder Electronic Speed Control. This is a type of ESC designed by a gentleman, Benjamin Vedder, and is considered an open-source ESC. This mean that you can modify the parameters of the ESC using configuration tools (i.e. BLDC) on your computer. This means you can fine tune the performance of the board (i.e. smoother acceleration, braking, etc..). Note that there are many variations of VESC. (i.e. VESC-X (FOCBOX), VESC 4.12 or lower versions (supply up to 27 amps continuous), VESC 6 (supply up to 50 amps continuous))
VESC-X (FOCBOX) - Image from diyelectricskateboard.com
Wh = Watt-hours. It is an unit applied to a battery defining its total capacity and is calculated by Amp-Hours x Nominal Voltage. For example, a 12 Volt battery with 20 Amp-Hours capacity is 240 Wh.