What motors are legal in FTC and how do they compare?

All legal FTC motors use a 12V RS-555 type bare motor, with a free speed of approximately 6,000 RPM and a stall current of around 10A . The primary differences between motors from various vendors lie in their gearboxes, including the gear ratio, output shaft type, and ease of mounting .

Legal motors include:

AndyMark NeveRest motors
REV Robotics HD Hex motors
goBILDA motors

The bare motors used by these manufacturers are virtually identical, with slight differences in specifications mainly due to varying testing methods .

Key components of these motors include:

Bare motor A 12V RS-555 type motor .
Gearbox Attached to the front of the motor, it reduces speed and increases torque. Gearboxes also contain the output shaft, which can be an 8mm REX shaft, 5mm hex shaft, or 6mm D shaft . Gearboxes can be replaced and this is FTC legal . Spur gearboxes are not recommended for motors due to shorter lifespan and lower mechanical resilience compared to planetary gearboxes, especially in high-load applications like drivetrains . Planetary gearbox motors are suggested for new purchases .
Encoder Attached to the back of the motor, it contains a sensor that registers motor shaft rotation. Encoders can be connected to REV hubs for precise control of motor speed or position . These are relative encoders, meaning position information is lost between power cycles, and they must be plugged into encoder ports near the motor ports .

Motor connectors vary by vendor:

JST VH connector (REV motors, some AndyMark NeveRest motors)
3.5mm Bullet connector (goBILDA motors)
Anderson PowerPole (some AndyMark NeveRest motors)

Adapters are available from REV Robotics, goBILDA, and AndyMark to connect motors with 3.5mm Bullet or Anderson PowerPole connectors to REV hubs, which use JST VH connectors . Motor power cables can be extended or shortened using 18 gauge or thicker cables, or by purchasing extender cables .

goBILDA motors, specifically their Yellow Jacket motors, use orbital gearboxes and offer a wide selection of 10 different gear ratios, ranging from 30 RPM to 1620 RPM, which is a broader range than other manufacturers provide out of the box . goBILDA motors can also face mount natively into channel .

Was this right?

Sources6

Choosing a Motor > Legal Motors

Game Manual 0·CC BY-NC 4.0

Bare motor. In all cases above, this is a 12V motor of RS-555 type, with free speed around 6,000 RPM and stall current around 10A. The motor specs posted by different vendors might be slightly different, but the difference is mainly due to different testing methods. In real life, the bare motors used by AndyMark NeveRest motors, REV Robotics HD Hex motors, and goBILDA motors are virtually identical. The most reliable specs can be found in the motor-data section.
Gearbox. The gearbox is attached to the front of the motor and reduces the speed while increasing the torque. For example, a 20:1 gearbox reduces the speed by a factor of 20, resulting in a no-load speed of around 300RPM. See Gear Reduction. A gearbox also contains the output shaft (typically a 8mm REX shaft, 5mm hex shaft, or 6mm D shaft) and mounting holes. The gearbox can also be replaced; this is FTC legal but requires some skill.
Encoder. Attached to the back of the motor and protected by a plastic cap, the encoder contains a sensor registering motor shaft rotation. It can be connected to REV hubs and used for precise control of motor speed or rotating to a specific position.

Since the bare motor is similar for all motors discussed above, the choice of the right motor is dictated by the gearbox: the gear ratio, output shaft type, and ease of mounting.

Open Game Manual 0

Control Systems

Game Manual 0·CC BY-NC 4.0

The FTC® control system is based around a "Robot Controller" and a "Driver Station". The Robot Controller is mounted on the robot. It is either embedded within or connected to special "Hub(s)", which in turn connect to motors, servos, and sensors. The Robot Controller is linked to the Driver Station through WiFi or WiFi Direct.

REV Robotics is the sole manufacturer of legal FTC control system components. The REV Expansion Hub connects to motors, servos, sensors, and a Robot Controller. A REV Control Hub has the same functionality of an Expansion Hub but with a built-in Robot Controller.

More information about the FTC Control System can be found below:

Official Control System Documentation on FTC Docs (https://ftc-docs.firstinspires.org/en/latest/programming_resources/shared/control_system_intro/The-FTC-Control-System.html)
REV Control System Documentation (https://docs.revrobotics.com/duo-control/)
Official troubleshooting guide (https://ftc-resources.firstinspires.org/ftc/archive/2026/team/robot-troubleshooting)

There are two possible control systems that can be run on an FTC robot legally:

REV Control Hub + REV Expansion Hub
RC Phone + REV Expansion Hub(s)

Open Game Manual 0

Gearbox Internals > Spur Gearboxes > Advantages of Spur Gearboxes

Game Manual 0·CC BY-NC 4.0

Danger: Spur gearboxes are NOT recommended for motors due to their shorter lifespan and lower mechanical resilience compared to planetary gearboxes. If you are purchasing new motors, it is highly suggested to purchase planetary gearbox motors instead. Care should be taken to not put load on the output shaft of a spur gearbox. In particular, spur gear motors should NOT be used in high load applications, such as a drivetrain.

Generally, spur gearboxes are cheaper than planetary gearboxes. However, in FTC that price change is often minimal. An HD Hex Motor + UltraPlanetary gearbox kit from REV is only ~$10 more than an HD Hex Motor + Spur gearbox, and offers significantly more flexibility/customizability.

Spur gearboxes from different vendors are not interchangeable. However, they are comparable and practically indistinguishable in performance. The main thing to consider here is your desired reduction, your desired motor connections, and your desired output shaft type.

Open Game Manual 0

Motor Wiring And Mounting

Game Manual 0·CC BY-NC 4.0

Depending on the vendor, the motors can come with one of the following connectors:

JST VH connector (REV motors, some AndyMark NeveRest motors)
3.5mm Bullet connector (goBILDA motors)
Anderson PowerPole (some AndyMark NeveRest motors)

Since REV hubs use JST VH connectors, to connect a motor with 3.5mm Bullet or Anderson PowerPole connectors, you need adapters which you can purchase from REV Robotics, goBILDA, and AndyMark.

You can extend or shorten motor power cables by soldering additional length of cable. This is legal as long as you use 18 gauge or thicker cables. Teams can also purchase extender cables to chain multiple pieces of cable together.

For more tips on wiring the robot, see /docs/power-and-electronics/wiring.

Open Game Manual 0

Encoders > What Are Encoders? > Relative Encoders

Game Manual 0·CC BY-NC 4.0

Ranging from the built in encoder in every FTC legal motor to common external encoders like the REV Through Bore encoder, these encoders track the relative position of the shaft or mechanism they are attached to. What this means is that the position output is relative to the initial position at robot power on, meaning position information is lost between power cycles.

Tip: Relative encoders don't reset to zero at the beginning of OpModes! You can use STOP_AND_RESET_ENCODERS to ensure that your encoders are always at zero at the beginning of an OpMode (see below).

All relative encoders in FTC use the "quadrature" protocol to send position information to the expansion hub. As a result, relative encoders must be plugged into the encoder ports located near the motor ports in order to function.

Open Game Manual 0

goBILDA > Kit of Parts

Game Manual 0·CC BY-NC 4.0

2023-2024 Kit Parts (https://www.gobilda.com/ftc-starter-kit-2023-2024-season/)

goBILDA's Low-Side U-channel opens up many new possibilities due to its flexibility and compactness. For example, one can now make a parallel plate drivetrain without custom machining, or make custom width U-channel.
goBILDA also has Servoblocks (identical to Actobotics other than hole pattern) which drastically increase servo life.
goBILDA has native large bore hex shaft support (12 mm REX is comparable to 3/8" rounded hex) which is one of the main advantages of custom fabrication brought to a kit based system.
goBILDA also is able to interface with TETRIX channel because they share some holes. For more information about TETRIX-goBILDA compatibility, check out this website (https://gobildatetrix.blogspot.com/). It is also quite compatible with REV's ecosystem.
goBILDA has a well thought-out ball bearing based motion system with smart motion transfer. It is easy to do chain or belt in channel.

Note: 8mm chain, HTD 3, and HTD 5 mm belt can do perfect C2C (center to center) on the goBILDA pattern. This saves a lot of headache when needing to calculate C2C distances.

goBILDA has plenty of shaft, ball bearing, and pillow block options.
goBILDA motors can face mount natively into channel, eliminating the need for motor mounts and providing a robust, reliable way to mount motors.
goBILDA has some special parts are unavailable in other systems, like square beam shafts.
goBILDA provides a large selection of 12V DC motors. Their Yellow Jacket motors use orbital gearboxes and are available in 10 different gear ratios ranging from 30 RPM to 1620 RPM. No other manufacturer offers such varied gear ratios out of the box.

Open Game Manual 0