REV Robotics for FRC: NEO Motors, Spark MAX/Flex, PDH & MAXSwerve

If you have opened an FRC kit of parts in the last few seasons, you have almost certainly touched a REV Robotics part. REV makes the motors, controllers, power distribution, sensors, gearboxes, and swerve modules that a huge share of teams now build on. For a rookie deciding what to buy, or a veteran weighing REV against Cross The Road Electronics (CTRE), the hard part is not finding REV gear — it is understanding how the pieces relate and which part number you actually need.

This guide walks the REV FRC ecosystem: the NEO motors, the Spark MAX and Spark Flex controllers, the Power Distribution Hub, the MAXSwerve module, and the sensors and gearboxes that tie a drivetrain together. Every part number and spec below was checked against REV's own product pages and documentation — but use it as a map, not a datasheet, and confirm the current spec on the product page before you order.

Who is REV Robotics, and why teams build on their ecosystem

REV Robotics is a US-based company that designs and sells parts for FIRST programs (FRC, FTC, and FLL) and general robotics. In FRC, REV rose to prominence by making a brushless motor — the NEO — that was cheaper, lighter, and more powerful than the brushed motors teams had relied on for years, and pairing it with an affordable smart controller, the Spark MAX. Once a team could buy a capable brushless drivetrain for roughly the price of an old brushed setup, adoption snowballed.

The bigger reason teams standardize on REV is that the parts are designed as a system. REV markets much of the FRC line under the "REV ION" umbrella: structure, motion components (MAXPlanetary gearboxes, MAXSwerve), electronics (NEO motors, Spark controllers, the PDH), and software (REV Hardware Client, REVLib) share hole patterns, connectors, shaft standards, and one configuration workflow. That is worth a lot to a time-strapped student team: fewer adapters to fabricate, fewer wiring surprises, and one app that talks to every device on the robot.

REV FRC product quick-reference

Students search REV parts by exact part number, so here is the core FRC lineup with verified part numbers and one-line roles. Specs for each follow below.

The motors: NEO, NEO Vortex, and NEO 550

REV's FRC motor family is three brushless motors that cover most of what a robot needs. All three carry an integrated Hall-effect sensor, which lets the Spark controllers do closed-loop velocity and position control without a separate encoder for basic use. For how these stack up against CTRE's Kraken and Falcon, see our FRC motors comparison.

NEO Brushless Motor (REV-21-1650)

The NEO is the workhorse — the motor most teams use for drivetrains, elevators, arms, and anything that needs sustained torque. The V1.1 is the current revision.

Verified specs at 12V nominal:

• Free speed: 5676 RPM
• Stall torque: 2.6 Nm
• Stall current: 105 A
• Free running current: 1.8 A
• Peak output power: 406 W
• Motor Kv: 473
• Integrated Hall-sensor encoder: 42 counts per revolution
• Output shaft: 8 mm keyed
• Weight: about 0.938 lb (0.425 kg)

The 8 mm keyed shaft mates directly with REV's gearbox input couplers. The 42-count Hall encoder is fine for velocity control and rough position; for precise positioning you will usually add a higher-resolution encoder.

NEO Vortex (REV-21-1652)

The NEO Vortex is REV's high-performance motor, designed alongside the Spark Flex. Its headline feature is a dockable controller interface: a Spark Flex mounts directly onto the motor, or a NEO Vortex Solo Adapter lets any brushless controller (like a Spark MAX) drive it.

Verified specs at 12V nominal:

• Free speed: 6784 RPM
• Stall torque: 3.6 Nm
• Stall current: 211 A
• Free running current: 3.6 A
• Peak output power: 640 W
• Motor Kv: 565
• 7 pole pairs
• Encoder resolution: 42 counts/rev with Spark MAX; 7168 counts/rev with Spark Flex
• Weight: about 0.99 lb (447 g)

That jump to 7168 counts per revolution with a Spark Flex is why the Vortex-plus-Flex combination is compelling for precise closed-loop control — high-resolution feedback with no external sensor.

NEO 550 (REV-21-1651)

The NEO 550 is the small, fast motor. It spins far faster and makes far less torque than the full-size NEO, which makes it ideal for lightweight, high-speed mechanisms: intakes, shooters, turrets, and swerve steering.

Verified specs at 12V nominal:

• Free speed: 11,000 RPM
• Stall torque: 0.97 Nm
• Stall current: 100 A
• Free running current: 1.4 A
• Peak output power: 279 W
• Motor Kv: 917
• Weight: about 0.313 lb (0.142 kg)

The NEO 550 stalls easily and can overheat fast because of its small mass. Always current-limit it in software and gear it so it never sits near stall under normal use.

How to choose between them

Rule of thumb: use the NEO for drivetrains and torque-hungry mechanisms, the NEO Vortex for more power or high-resolution feedback in a similar footprint, and the NEO 550 for small mechanisms where speed and low weight beat raw torque. Getting the reduction right is a gear-ratio problem — our FRC gear ratios guide covers converting free speed into the output speed and torque your mechanism needs.

Spark MAX vs Spark Flex: choosing a controller

A brushless motor cannot run without a controller to commutate it, and REV sells two "smart" controllers. Both are closed-loop capable and talk over CAN, USB-C, and PWM. The choice mostly comes down to which motor you are driving and what feedback you want.

SPARK MAX (REV-11-2158)

The Spark MAX is the versatile one. It drives both brushed 12V motors and sensored brushless motors like the NEO and NEO 550 — handy, because you can standardize on one controller across a robot that mixes brushless drive motors and legacy brushed mechanisms.

Verified specs:

• Continuous current: 60 A
• Peak current: 100 A (2-second surge)
• Operating voltage: 5.5–24 V (absolute max 30 V)
• Interfaces: CAN, USB-C, and PWM (locking, keyed 4-pin JST-PH for PWM/CAN)
• Closed-loop velocity control, closed-loop position control, and follower mode
• Roughly 70 x 35 x 25.5 mm, about 113 g

Because it handles brushed motors, the Spark MAX is the controller REV specifies for the MAXSwerve azimuth motor, and it is the safe default unless you are building around a NEO Vortex.

SPARK Flex (REV-11-2159) and the NEO Vortex pairing

The Spark Flex is the newer controller built to unlock the NEO Vortex. Its dockable form factor mounts straight onto a Vortex to cut wiring, and with a Flex Dock it becomes a standalone controller that drives a NEO or virtually any 12V brushed DC motor.

Verified specs:

• Continuous current: 60 A
• Peak current: 100 A (2-second surge)
• Operating voltage: 6–24 V (nominal 12 V, absolute max 30 V)
• Interfaces: CAN, USB-C, and PWM
• Advanced control modes: velocity, position, and current
• A 5V/500 mA supply output and digital/analog inputs on the data port

Reach for a Spark Flex when you want the Vortex pairing: docked to a NEO Vortex it reads that 7168-count encoder, adds a current-control mode, and gives you the ecosystem's highest-performance single-motor package. For plain NEOs, a Spark MAX is all you need.

Compatibility check before you buy: a Spark Flex docks natively to a NEO Vortex, but to run a NEO Vortex from a Spark MAX you need the NEO Vortex Solo Adapter. To run a NEO Vortex or Falcon 500 as the drive motor in a MAXSwerve module you need a replacement drive shaft — confirm the part numbers on the product page for your build.

Powering it all: the Power Distribution Hub (REV-11-1850)

Every FRC robot needs one board that takes the main battery leads and fans power out to every device. REV's answer is the Power Distribution Hub (PDH), their alternative to CTRE's Power Distribution Panel.

Verified specs and features:

• 20 high-current channels (40 A max each, sized for ATO breakers/fuses)
• 3 low-current channels plus 1 switchable low-current channel (15 A max, ATM fuses) — 24 channels total
• Toolless latching WAGO terminals, so you push wires in without a screwdriver
• Onboard LED display that shows battery voltage
• CAN and USB-C connectivity for real-time telemetry in the REV Hardware Client
• About 517 g (1.14 lb)

Teams love the PDH for two things: the WAGO terminals (much faster than screw terminals, and one fewer thing to shake loose) and the per-channel current telemetry over CAN for debugging a mechanism that browns out or a motor drawing too much. We go deeper on wiring and channel planning in the dedicated PDH guide.

The PDH reports per-channel current over CAN. Log it during matches — a channel pulling far more than expected is often your first sign of a mechanical jam or a failing motor, well before it becomes a fire drill in the pit.

MAXSwerve: REV's swerve module

Swerve drive — where each wheel can both spin and steer independently — is now the dominant FRC drivetrain, and MAXSwerve (REV-21-3005) is REV's complete swerve module. New to swerve? Start with our swerve drive explainer first.

Verified details for the 3in MAXSwerve Module:

• 3-inch diameter wheel
• Drive motor options: NEO, NEO Vortex (with replacement shaft REV-21-2848), or Falcon 500 (with replacement shaft REV-21-2094)
• Azimuth (steering) motor: NEO 550, driven through an UltraPlanetary gearbox
• Azimuth ratio: about 46.42:1 (exactly 9424:203)
• Steering feedback: a Through Bore Encoder reading absolute angle directly on the turning axis (10-bit resolution)
• Base kit includes three drive speed ratios (low, medium, high); an upgrade kit (REV-21-3008) adds additional high-speed ratios

The azimuth uses a small, cheap NEO 550 because steering needs precision, not torque — and that precision comes from the absolute Through Bore Encoder on the steering axis, so the module knows which way each wheel points at power-on. The drive motor is your choice.

Plan four drive controllers plus four steering controllers — eight motor controllers total — plus the CAN wiring to reach them all, when you budget a swerve robot.

Sensors and gearboxes: Through Bore Encoder and MAXPlanetary

Through Bore Encoder (REV-11-1271)

The Through Bore Encoder is REV's general-purpose absolute encoder, and it shows up all over the ecosystem — most notably as the steering sensor in MAXSwerve. "Through bore" means the measured shaft passes through the middle of the encoder, so you mount it coaxially with a rotating axis instead of off to the side.

Verified details:

• Uses a Monolithic Power Systems MA600 magnetic angle sensor to read the absolute position of a magnet on the shaft
• Provides 10-bit absolute angular resolution
• Ships with hex and round bore inserts (3/8 in hex, 5 mm hex, 1/4 in round) so it fits common FRC shafts
• Multiple cable options for connecting to a controller data port or a roboRIO DIO port

Because the output is absolute, the encoder knows the true angle the instant the robot powers on — no homing routine required, exactly what a swerve steering axis needs.

MAXPlanetary gearbox

The MAXPlanetary is REV's modular, cartridge-based planetary gearbox designed for NEO-class motors (it also supports NEO 550, Falcon 500, and 775 motors). Instead of a fixed-ratio gearbox, you start with a base and stack reduction cartridges to hit the ratio you want, then re-stack them later when your design changes.

Verified part numbers:

• MAXPlanetary Base Kit: REV-25-2109 (universal input stage, 1/2 in hex output, input coupler and shaft)
• 3:1 cartridge: REV-21-2101
• 4:1 cartridge: REV-21-2102
• 5:1 cartridge: REV-21-2103
• 9:1 cartridge: REV-21-2129

Because cartridges stack, a handful combine into a wide range of ratios, and because they are self-contained you can swap a ratio in the pit without tearing down the drivetrain. Choosing the actual reduction is a gear-ratio calculation — our gear ratios guide is the companion piece.

The software: REV Hardware Client and REVLib

REV Hardware Client is a desktop application that talks to REV devices over USB-C or CAN. You use it to update firmware, assign CAN IDs, tune and test motors on the bench, and watch live telemetry from the PDH and Spark controllers — it is the first thing you run on a new device before it ever touches robot code.

REVLib is the vendor library you install into your WPILib robot project so your code can command REV devices. It provides the classes for controlling Spark MAX and Spark Flex — setting output, configuring current limits, reading the integrated encoder, and running the onboard closed-loop velocity and position controllers — and it is available for Java, C++, and Python (RobotPy). You add it as a vendordep URL, like any third-party library.

Firmware and library versions must be compatible. Before each season's first build day, update every device's firmware in the REV Hardware Client and update REVLib to matching versions. Mismatched versions are a classic source of "the motor won't respond" bugs.

Every REV smart device rides on the CAN bus, and a swerve robot can easily have a dozen or more sharing it — if you are chasing intermittent "device not found" errors, read our CAN bus guide before you build the harness.

REV vs CTRE: how to choose

The two ecosystems most FRC teams pick between are REV and CTRE (Cross The Road Electronics, maker of the Kraken X60, Falcon 500, and the Phoenix software stack). Both win events every year, so this is rarely a right-versus-wrong call.

Teams lean REV for lower entry cost, the versatile Spark MAX that also drives brushed motors, the tightly integrated ION build system, toolless PDH wiring, and REVLib's straightforward API. Teams lean CTRE because the Kraken X60 and Falcon 500 integrate the motor and controller into one unit (fewer controllers to wire), the Phoenix 6 software and CANivore tooling are very polished, and the performance ceiling is high — at the cost of price and heavier reliance on one vendor's stack.

The most durable answer for a student team: pick the ecosystem your mentors and nearby teams already know, and standardize on it. A well-supported REV robot beats a half-understood mixed-vendor robot every time — you can always mix specific parts later once you know both stacks.

Frequently asked questions

What is the difference between a NEO and a NEO Vortex?

Both are sensored brushless motors, but the NEO Vortex (REV-21-1652) makes more power — about 640 W peak versus roughly 406 W for the NEO (REV-21-1650) — and supports a dockable Spark Flex controller that reads a 7168-count-per-revolution encoder. The NEO is the cheaper, proven workhorse; the Vortex is the higher-performance, higher-resolution option in a similar footprint.

Can the Spark MAX control brushed motors?

Yes. The Spark MAX (REV-11-2158) drives both 12V brushed motors and sensored brushless motors like the NEO and NEO 550 — one controller can run a brushless drivetrain and a legacy brushed mechanism, which is a big reason teams standardize on it.

Do I need a Spark Flex to run a NEO Vortex?

No, but it is the intended pairing. A Spark Flex (REV-11-2159) docks directly onto a NEO Vortex and reads its high-resolution encoder. You can instead run a Vortex from a Spark MAX by using the NEO Vortex Solo Adapter, though you lose the docked convenience and the higher encoder resolution.

How many channels does the REV PDH have?

The Power Distribution Hub (REV-11-1850) has 24 channels total: 20 high-current channels rated to 40 A each, plus 3 low-current channels and 1 switchable low-current channel rated to 15 A. It also reports per-channel current over CAN for debugging.

What motors does MAXSwerve use?

The 3in MAXSwerve module (REV-21-3005) uses a small NEO 550 for steering (azimuth) through an UltraPlanetary gearbox, and your choice of drive motor — a NEO, or a NEO Vortex or Falcon 500 with the appropriate replacement drive shaft. Steering position is read by an absolute Through Bore Encoder on the turning axis.

What software do I need for REV devices?

Two things: the REV Hardware Client (a desktop app for firmware updates, CAN ID assignment, and bench testing) and REVLib (the vendor library you add to your WPILib project to control Spark MAX and Spark Flex from Java, C++, or Python). Keep firmware and REVLib versions matched to avoid connection bugs.

REV's real advantage is not any single part — it is that the motors, controllers, power distribution, sensors, and gearboxes were designed to work together through one app and one library. Learn the ecosystem as a system, keep firmware and REVLib in sync, and confirm every part number on the product page before you order. When you are ready to go deeper on any one piece, the guides library has companion walkthroughs for motors, swerve, gear ratios, and the CAN bus.