Motor Wiring And Mounting

Power Connections

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

JST VH is probably easiest to use, as it is the same connector used by REV Control/Expansion Hubs. It is also locking. PowerPoles are very reliable and sturdy but somewhat bulky. 3.5mm Bullet connectors are very compact, making cables easy to route through openings, but can be disconnected.

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 Wiring Guide.

Encoders

Note

Encoder cables are very fragile. Take care to protect them from snagging and sharp impacts! It may be prudent to inspect encoder wires once in a while.

If using encoders, you need to connect them to the REV hub by a 4-wire cable. REV Hub uses 4-pin JST PH connector for encoder ports. REV motors also use JST PH encoder ports, so you can connect them to the hub by JST PH 4-wire cable, available from REV Robotics.

goBILDA and AndyMark motors use JST XH 4-pin encoder port (note the difference: XH vs PH), so to connect them, you need a JST PH to JST XH cable, available from goBILDA and AndyMark.

Mounting Motors

There are two ways to mount a motor: using a clamping mount (such as 32mm goBILDA clamping mount ) or face mounting, using threaded holes in the front face of the gearbox.

Clamping Mount

  • Not as secure as face mounting, as clamp friction is looser than face mounting using screws.

  • Some gearboxes (particularly spur gear) do not place the output shaft in the center of the gearbox.

    Thus, motors with offset shafts are particularly sensitive to clamp mounts, as any rotation of the motor will alter the shaft position. This may have the consequence of losing chain or belt tension.

  • It is possible to double clamp a motor - one in front, and one in the back.

  • To increase friction and reduce the chance of loosening, one can wrap electrical tape around the area of the motor that will be clamped down. Use a couple wraps of tape.

Face Mount

  • Face mounting is much more reliable than clamp mounting, as the screws hold the motor in place very tightly.

  • Teams can use BLUE Loctite on high-vibration motors to ensure the motor does not jar loose.

Tip

Face mounting is recommended for high-load and/or high vibration use cases such as drivetrain. This is as clamp mounted motors can shift and come loose easier than face mounted motors. It is also recommended to use BLUE Loctite when face mounting, if possible.

Note that the pattern of face mounting holes is different for different vendors. For example, goBILDA uses 4 M4 holes in a square with side 16 mm, whereas AndyMark classic motors use 6 M3 holes on a 31 mm diameter circle. Thus, face mounting NeveRest motors to goBILDA parts requires use of special adapters, and vice versa. Similarly, gearbox diameter also varies between motors, so when choosing a clamping hub, make sure to use the right diameter.