Making Connections¶

This page covers everything needed for you to make successful connections in the FRC Control System.

Crimping Connectors¶

Molex Connectors: These are the preferred choice for CAN and high AWG power wire.
The most common type of Molex connector in FRC is the Molex SL series, though other variants are also sometimes used.
They are low-profile, shrouded connectors available in pin and socket configurations, making them easy to assemble and highly reliable. Their housings also contain latches, which ensure secure connections.
Two-pin Molex SL is the standard for integration into SystemCore and Adapter boards for Krakens.
Using the TPA is also heavily recommended, as it raises the terminal retention from 17.5 N to 50+N, as seen in the poster.
This image shows the Molex SL connector.

Molex SL

Anderson Connectors: For lower AWG power wire, Anderson connectors are the preferred choice, with SB50 for battery wires and Powerpole for 10-12 AWG wires.
The TRIcrimp is recommended for crimping, as well as the tin-plated connectors.
This image shows the Anderson SB50 connector.

Anderson SB50

Anderson Powerpole

Powerpole Adapter Boards
These boards convert Kraken ring-terminal outputs into Anderson Powerpole and Molex SL connections, making wiring cleaner and easier to service.
This image shows the Powerpole adapter board.

Powerpole Adapter Board

JST: JST connectors are commonly used for low-current signal wiring.
These can be found in sensors, encoders, LEDs, and other low-power devices.
Their compact polarized design helps keep them organized while preventing incorrect connections.
The most common type of JST connector in FRC is the JST-PH series.
This image shows the JST-PH connector.

JST-PH

Ferrules: Ferrules are used for stranded wires that connect to the ports of components like the RIO or PDH as well as for connections that involve linear WAGOs.
They prevent stray wires from causing short circuits.
This image shows a ferrule.

Ferrule

Dupont: Dupont crimps were commonly used for roboRIO connections, but are not recommended for new robots. With Systemcore, Molex SL is recommended for connections because of its locking latches that prevent wires from accidental disconnections.
This image shows a Dupont connector.

Dupont

Crimping Molex SL (Guide)
The following pinout is compatible with both SystemCore and the Powerpole adapter boards. It is recommended to use a consistent pinout throughout the robot to avoid having to rewire connections if a CAN device needs to be replaced.

Molex SL Standard CAN Pinout

To prevent accidentally feeding a device -12V instead of +12V, it is recommended to use standard Anderson Powerpole pinout. This standard has been adopted by amateur radio organizations, the Powerpole adapter board, the Powerpole Fused Distribution Board, and permanently bonded housings.

Powerpole Polarity

Powerpole Quality

Solder connections, as opposed to crimped connections, can be made for connections between wires

Warning

FRCElectrical.org does not recommend soldering for FRC robots.

They are more prone to failure under vibration and stress
Repairing solder joints is more time-consuming and difficult in competition stress
Solder can be a good conductor, however, brittle connections can lead to failure that crimped connections do not have.
Similarly, for newer teams, it requires more of a learning curve and practice to get right.
Large gauge wire should not be soldered as it is typically a failure point on the robot.
This is a failure point as it is incredibly hard to apply enough heat to create a proper joint. This can lead to a brittle connection that can fail.
Solder Sleeves: Solder sleeves are not recommended for FRC robots.
They use low-melting-point solder and rely on heat to both solder the wire and shrink the tubing, making it difficult to achieve a consistent, reliable connection.
If not heated correctly, they can create weak electrical or mechanical joints that may fail under the vibration and impacts experienced during competition.
Properly crimped connectors are the preferred solution.

For temporary connections
In Wiring LEDs, where you need to connect an LED strip to the CANchain (if applicable) or power
To create custom 120 Ohm Resistors, which are used to terminate the CAN bus
Soldering is a skill that is used in the workforce. FRCElectrical.org does not recommend it for newer teams that wish to create connections on an FRC Robot.
However, if you are experienced with soldering, it can be a useful skill to have (and teach!)

The Lineman Splice, also known as the NASA Splice, is one of the most widespread types of solder splices in use due to it's reliability and ease of use. The following figure is taken from NASA-STD-8739.4

Lineman Splice

Tips for soldering a lineman splice:
- The stripped section of wire should be pre-tinned to form solid sections with just enough solder to hold the strands together.
- The wires should be wrapped around each other as shown. The wraps should be tight without overlapping, then trimmed flush. The wire should not overlap the insulation.
- Solder should be applied to the wraps. The entire connection should be covered with solder, but the underlying shape should still be visible.
Like all soldered connections, the solder creates a more rigid section of wire which is more vulnerable to breaking. When routing and securing wires, the wire should be secured to prevent repeated bending of the soldered area.

Inline WAGO

Y/G WAGO

A tug test is a method of testing the strength of a connection
It is recommended to perform a tug test on all connections to ensure they are secure
This is especially important for connections that are subject to stress
Performing tug tests on connections can help identify weak points in the robot's wiring before it is on the competition field.
You do not need to pull as hard as possible, just enough to ensure the connection is secure.