Lingo Tutorial - Novice
Last updated - July 2006
DISCLAIMER: Combat robotics is a dangerous sport by it's nature. Extreme caution should be taken when performing any operation explained on this site. Any injury or death resulting from the use of these pages is the sole responsibility of the user and not totalinsanity.net. By undertaking the construction of a combat robot you assume all responsibility for your actions. When building a combat robot, always make sure you are, or are with, a responsible adult.
This isn't a tutorial so much as it is a dictionary of commonly used combat robotics words. Below is an alphabetical list of all commonly used words in the sport of combat robotics. If you have a question about a word not listed below, please, ask us! We recommend going over this list and reviewing any terms you don't recognize before reading our other tutorials.
2.4 GHz Radios - These just started showing up in R/C sports around the year 2006. Eliminating the need for crystals, these radios will almost never cause, or receive, any interference. These are the cream of the crop as far as ease of use is concerned. PCM radios still seem to have more features, but $200 2.4 GHz radios will do almost anything you will ever need, and completely avoid the hassle of crystals.
AntWeight - Abbreviated AW, this is a weightclass for robots weighing 1 pound or less.
AM Radios - These are the cheapest, and worst radios. These should NOT be used for robot combat, even in the antweight class. They simply pick up too much interference and cause iratic robot movement. These radios are found in most cheap toy R/C cars.
Amperage - Electricity is measured in voltage, and amperage. Amperage is also referred to as current. An easy way to think of this is that in relation to water flow in a pipe, amperage would be the flow rate, and voltage would be the pressure. As far as what you need to know about this and motors: Voltage will spin a motor faster, and amperage will make it spin with more force behind it. If you increase the voltage to a motor, it will automatically draw more amperage.
Amp Hours - Ah - This is a rating unit for batteries. A rating of 2 Ah means a battery can deliver 2 amps for 1 hour continuously. Theoretically it should also mean that you can divide the Ah rating by the amps you want to use, to find how long your battery will last. So a 2 Ah battery, when delivering 4 amps, should last for a half hour. Batteries tend not to work as well at high amperages however.
AWG - "American Wire Gauge" is a wire rating standard. Lower numbers are thicker wires.
BeetleWeight - Abbreviated BW, this is a weightclass for robots weighing 3 pounds or less.
Brushes - Brushes are an internal part in an electric motor. An electric motor works with electro magnets attached to the spinning shaft. Brushes power these electro magnets by running along a metal ring as the shaft spins.
Brushless Motor - An electric motor that has no "brushes." Since there is no friction from the brushes, these motors are much more efficient, but require advanced (and expensive) controllers.
Channel - A Channel, in reference to an R/C unit, can refer to one of two things.
A "4 channel" radio refers to a way to control something on your robot. Each individually actuated part of your robot will require a free channel. Make sure to have enough channels on your radio to control all of your systems. Most robots only need a 3 channel radio, but more may be necessary depending on your design.
When in reference to radio crystals, it refers to which part of the frequency band your radio operates on. Say, 75.1mhz or 75.2mhz if using a 75 MHz radio. The crystals are given easy to understand numbers, and if you want to fight another robot, just make sure you are on a different numbered channel.
Commutator - This is an internal component in a brushed DC electric motor. The brushes in an electric motor run along a commutator which is how the inner workings of a DC motor are powered.
Crystals - Crystals are used in FM & PCM style radios to control which channel a radio operates on. They look like a small metal rectangle with two prongs coming out. If two FM or PCM radios are on the same channel, they will interfere. If you have an FM or PCM radio you must bring extra crystals to any competition to make sure you won't interfere with your opponent's robot.
Current - see Amperage
Delrin - A very slippery plastic, great for skidplates.
ESC - Electronic Speed Control - This is what is used to directly control your robot's motors. They take the signal output of the receiver, and use it to control how fast your motor spins by varying the voltage output to the motor. You cannot simply plug your motor into the receiver, you must have an ESC to interpret the output of the receiver.
FairyWeight - Abbreviated IW, this is a weightclass for robots weighing 150 grams or less.
FeatherWeight - Abbreviated FW, this is a weightclass for robots weighing 30 pounds or less.
Frequency - This refers to how your radio operates, and is measured in Hz. What is important to note is that 72 MHz systems are NOT legal for use in combat robotics. 27 MHz, 75Mhz or 2.4 GHz systems must be used.
FM Radios - These are used in many of the lower weightclasses, sometimes as high as the 30 or 60 pound classes. These radios are better than AM in range and amount of interference, but cannot compare to PCM or 2.4 GHz radios.
HeavyWeight - Abbreviated HW, this is a weightclass for robots weighing 220 pounds or less.
HobbyWeight - Abbreviated YW, this is a weightclass for robots weighing 12 pounds or less.
Invertible - A robot is invertible if it is able to run upside down.
Kilobot - Abbreviated K, this is a weightclass for robots weighing 1 kilogram or less.
Lexan - A type of polycarbonate made by Dupont. See polycarbonate.
LightWeight - Abbreviated LW, this is a weightclass for robots weighing 60 lbs or less.
Linear Actuator - This can be powered by either electricity or pneumatics. They are used to power anything which needs to be "pushed" on. Flippers, overhead hammers, and spikes/ram rods are their most common use. They can be easily described as an extending rod.
Mantis - Abbreviated M, this is a weightclass for robots weighing 6 pounds or less.
Mecanum Wheels - A type of omni wheel that is mounted the same way as a normal 4wd robot's drive train. The rollers on the wheel are oriented at 45*. These wheels must be custom made, as no source for them is currently available.
Melty Brain - This is a method used to translate a thwack bot across the floor while it is spinning. This is accomplished by pulsing the motors. If you slow down a wheel, the robot will start to travel in that direction if it is spinning. By doing this many times a second and keeping track of the robots rate of rotation, a thwack bot can be piloted while spinning. There are many different ways of accomplishing this.
MiddleWeight - Abbreviated MW, this is a weightclass for robots weighing 120 pounds or less.
Motors - Usually powered by electricity, and rarely pneumatics, these power most anything that is spun.
Omni Wheels - Omni wheels allow a robot to translate in any direction, without rotating in place. To do this rollers are placed around the perimeter of the wheel. Advanced mixing techniques along with varying wheel/roller angles allow translation in all directions. These wheels are rare in combat robotics because of their usual lack of traction and complexity. However, they do offer a significant advantage in control.
Overhead Thwack Bot - These robots have two wheels, and a center of gravity just above their axle. They have a hammer extending out the back. The chassis is designed so that it is contained within the diameter of the two wheels, only the hammer extends past the wheels. The hammer acts as a wheely bar when going forwards. If the robot reverses, the hammer will swing around overhead, and come down on anything in front of it, before actually moving backwards.
PCM Radios - A step up from FM radios, these radios encode their transmissions to further reduce interference. These radios are normally used in expensive R/C airplanes and helicopters. Models of this type of radio have up to 9 different channels. They still operate on FM frequencies.
Permanent Magnet DC Motor - PMDC Motor - The standard type of motor used in robotic combat. This type of motor uses permanent magnets mounted to the case of the motor, with windings around a magnetic core spinning inside of them. These motors use brushes and are not as efficient as brushless motors. However, brushed motors are much cheaper, and also use cheaper controllers.
Piston - A pneumatically powered linear actuator.
Polycarbonate - A clear plastic, used in bullet proof "glass." A popular trade name of polycarbonate is "Lexan." Polycarbonate is a decent lightweight armor because of it's impact resistance, but it is not very resistant to cutting.
Pulley - Belts run along pulleys in belt drive systems.
Rack and Pinion - This is the same mechanism that is used to steer in a car. A standard gear, runs along a metal plate with gear teeth on it. This can serve one of two purposes. It can turn rotational motion into linear motion, or linear motion into rotational motion.
Radio - The control system used to control your robot. Similar to those used in R/C cars, boats, and planes. Types include PCM, FM, AM, and 2.4 GHz.
R/C - stands for "radio control" or "remote control."
RPM - stands for "rotations per minute." This is a measurement of how fast something is spinning.
Solenoid - A type of switch. Instead of being activated by someone externally flipping it on and off, an electromagnet is used to flip the switch on and off. The magnet is then powered by another external switch. The advantage is that a solenoid can switch large amperage draws, while the switches used to activate solenoids are generally very small.
Sprocket - Looks similar to a gear, but does not directly mesh together as gears do. Sprockets are used in chain drive systems, and they mesh with the chain links.
SuperHeavyWeight - Abbreviated SHW, this is a weightclass for robots weighing 340 pounds or less.
Tank Drive - This is a term for the type of drive used in most combat robotics. Each side of a drive is independently controlled. This is explained in our drive tutorial.
Thor - A popular single channel ESC produced by IFI Robotics. These can handle more amperage than a Victor.
Thwack Bot - This is a common type of robot for the novice builder. The designs consist of a chassis with two wheels, with static hammers mounted to the frame. The wheels are spun in opposite directions, which causes the robot to spin in place. The static hammers attacked to the frame are now spinning with the robot chassis, and become the weapons. The downside of this is that it requires the opponent to come up and hit you, while you are spinning in place.
Timing Belt - Similar to a normal belt, these belts have teeth. They are used in cars and other systems to make sure that the pulley's attached to the belt stay in "time" with each other and do not come out of sync. In robot combat this is not normally important, and it is better to use a normal belt. The teeth on timing belts tend to tear off in high torque situations.
Torque - Torque is like, force, except in relation to rotational systems. If a shaft is spinning, the more force is behind it, the more torque it has.
UHMW - A great plastic to use for mounting motors. Easily machineable and strong enough to hold a motor in place.
UniBody - A type of frame made of welded together plates of metal. These frames are not bolted together but instead are one solid piece of metal.
Vantec - A company that produces ESCs.
Veteran - A person who has competed in many competitions. If you want to ask someone a question, a veteran would be the person to ask.
Victor - A popular single channel ESC produced by IFI Robotics.
Voltage - Electricity is measured in voltage, and current. Current is also referred to as amperage. An easy way to think of this is that in relation to water flow in a pipe, amperage would be the flow rate, and voltage would be the pressure. As far as what you need to know about this and motors: Voltage will spin a motor faster, and amperage will make it spin with more force behind it. If you increase the voltage to a motor, it will automatically draw more amperage.
Weightclass - Just like in boxing, there are weightclasses in combat robotics. Your robot must weigh less than the limit for the class in order to legally fight.