Super Servo for FTC Swerve

I found this super servo that works like a DC motor, I ordered some to test but I’m not sure if the competition will limit this like the VEX EDR 393 since part 1 of the manual has already been released.

“ Servos – A maximum of twelve (12) servos are allowed. Any servo that is compatible with the
attached servo controller is allowed. Servos may only be controlled and powered by a REV Expansion Hub,
REV Control Hub, or REV Servo Power Module. Servos may be rotary or linear but are limited to 6V or less. All
servos must have a three-wire servo connector compatible with the REV Control Hub and REV Expansion Hub
servo ports and may also have an optional additional sensor position output interface.
The VEX EDR 393 motor is considered a servo for the purposes of actuator allocation. It must be used in
conjunction with a VEX Motor Controller 29 and a REV Servo Power Module. A maximum of two (2) VEX EDR
393 Motors per REV Servo Power Module is allowed.”

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Given the lack of absolute encoder support on the FTC control system (at least last I checked), wouldn’t a standard non-continuous servo be better for swerve applications since you could more accurately control your module direction?

Still, good to know about this. My only complaint is the D-shaft output.

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FTC rules on allowed servos are fairly loose. Under <RE10>, basically anything that:

  • takes 6 volts
  • uses the three-wire PWM interface for position and power

is fair game. There isn’t even the $75 cost cap that FRC has (yet.)

There are continuous position servos sold to the FTC market that do have that additional analog output, such as Axon’s MAX+ and MINI+ offerings. These also have pretty high output power as well.

Generally, FTC swerves use the analog outputs as position feedback for continuous servo configuration, but due to constraints on the control system, they can be tricky to control.

Personally, I wouldn’t really consider FTC swerve anywhere near as necessary as it is in FRC. The difference between swerve and mecanum in FTC is like the difference between diffy and COTS swerves in FRC – you theoretically might get some marginal benefits but it’s going to be a lot of hassle to do right.

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