MAXPlanetary System Overview

The MAXPlanetary System (REV-21-2100) is a cartridge-based modular planetary gearbox designed from the ground up for NEO-class motors. The design of the MAXPlanetary has been carefully optimized to provide torque density unavailable in FRC up until now.

The MAXPlanetary is intended for use with the NEO, NEO 550, Falcon 500, and 775 motors. Building on the ability to iterate and adjust designs easily, the MAXPlanetary System consists of lubricated cartridges, allowing for swapping gear ratios on the fly and with ease. Users can configure a single-stage planetary using one of five different reduction cartridges or build multi-stage gearboxes by stacking individual cartridges together. The user can use the included 1/2in hex shaft or use a custom length of hex shaft best suited for the application. The gearbox also provides two mounting options, face mount and side mount, for ultimate flexibility in your robot design.

MAXPlanetary Gearbox Features

The REV Robotics MAXPlanetary Gearbox includes the following features:

• Three different, self-contained gear ratio cartridges providing twenty-seven gear ratios ranging from 2:1 to 125:1

• High torque density

• Easy assembly without modifying the motor

• A Socket 1/2in Hex Output with the ability to retain a shaft blind

• Assembled front to back for ease of changing the gear ratio, while the MAXPlanetary Gearbox is mounted on the robot

MAXPlanetary Gearbox Cartridge Options

• 2:1 Cartridge (REV-21-2140)

• 3:1 Cartridge (REV-21-2101)

• 4:1 Cartridge (REV-21-2102)

• 5:1 Cartridge (REV-21-2103)

• 9:1 Cartridge (REV-21-2129)

MAXPlanetary 1:1 Brake Cartridge

The MAXPlanetary 1:1 Brake Cartridge enables your MAXPlanetary System to mechanically hold its position. A steel internal ring housed in a lightweight aluminum case provides excellent strength and durability while maintaining a compact standard cartridge size. The cartridge integrates seamlessly with all other MAXPlanetary stages and occupies only a single slot. Designed around the principles of a sprag clutch, sometimes referred to as a torque diode, clutch, or overrunning clutch, this cartridge prevents backdriving in either direction by locking the output whenever the motor or input is stationary. The brake engages automatically when the output velocity exceeds the motor velocity, and it can be reliably released because the unlocking torque is approximately eighty percent of the locking load.

The Brake Cartridge can be added anywhere within the gear stack assembly, however it is recommended to use the Brake Cartridge as the first cartridge, closest to the motor, before any gear reduction to maximize its life.

Specifications - MAXPlanetary 1:1 Brake Cartridge

MAX 90 Degree Gearbox

Designed with an efficient right-angle configuration, the MAX 90 Degree Gearbox offers a robust and high-performance solution to building a more compact robot. Connect the MAX 90 Degree Gearbox to the MAXPlanetary System in a 90-degree orientation for maximum flexibility and ease of use in tight spaces. The through bore design of the gearbox allows for easy mounting and integration into a wide range of applications. Its 90-degree output orientation provides a compact and efficient way to transmit power and torque at right-angle configurations.

The REV Robotics MAXPlanetary System includes the following features:

• Five different self-contained gear ratio cartridges that provide ultimate gearbox customization

• High torque density

• Easy assembly without modifying the motor

• A Socket 1/2in Hex Output with the ability to retain a shaft blind

• Assembled front to back for ease of changing the gear ratio, while the MAXPlanetary Gearbox is mounted on the robot

Cartridge Features

Input Spline - Accepts torque from the previous stage while being easy to insert and remove.

Output Spline - Provides torque transfer between one stage and the next while being easy to insert and remove.

Assembly Holes - The screws holding the gearbox together pass through these holes.

Shields - Keeps the internal components of the gear stage in their place when the stage isn’t assembled into a gearbox. Also retains grease to keep the gear stage lubricated throughout its service life.

Alignment Tabs - Alignment features that engage with the alignment notches on the previous stage. The directional nature of the alignment features prevents the user from assembling any gearbox components backwards.

Alignment Notches - Provides a socket for the alignment tabs to engage with. These features keep the rotating components concentric as well as providing angular alignment to keep the flat faces of the gearbox in plane.

Input Features

Side Mounting Holes - These 10-32 holes allow the gearbox to be mounted on top of structural components without obstructing the front of the gearbox.

Assembly Holes - The screws holding the gearbox together pass through these holes.

Alignment Notches - Provides a socket for the alignment tabs on the first gear stage to engage with. These features keep the rotating components concentric as well as providing angular alignment to keep the flat faces of the gearbox in plane.

NEO Mounting Holes - These holes are for mounting NEO-class motors to the input block.

550 Mounting Holes - These holes are for mounting the NEO 550 to the gearbox.

775 Mounting Holes - These holes are for mounting 775-series motors to the gearbox

775 Vent Holes - These holes line up with the vent holes on the face of 775-series motors and allow cooling air to pass through the motor.

MAXPlanetary Universal Input Stage V2 Additional Features

The MAXPlanetary Universal Input Stage V2 (REV-21-2146) is a redesigned mounting solution for integrating a wide range of FRC motors into the MAXPlanetary System. Built as the next evolution of the original universal input stage, V2 enhances strength, expands motor compatibility, and enables even more compact gearbox configurations.

• Updated universal input stage for MAXPlanetary System integrations

• New 1.375 inch bolt circle supports additional motor mounting (e.g. Kraken X44)

• CIM class motor pattern clocked 45 degrees for improved fitment and packaging

• Allows NEO 2.0 Brushless Motor flats to align flush for extremely compact assemblies

• Reinforced mounting tabs increased from 0.125 inch to 0.25 inch thickness

• Direct motor compatibility with no additional input kits required for:

  • NEO 2.0, NEO 1.1, NEO 1.0

  • Kraken X60, Kraken X44

  • Pulsar 775

  • CIM

• Compatible with additional motors when used with corresponding input kits:

  • NEO 550 (REV-21-2117)

  • Minion (REV-21-2139)

  • 775 and 775pro (REV-21-2118)

Output Features

Socket 1/2in Hex Output - Engages with a 1/2in hex shaft to drive a robot mechanism. The output includes a #10 clearance hole through the middle, which allows a shaft to be retained in the output.

Face Mounting Holes - These 10-32 holes allow the gearbox to be mounted to the face of a bracket or tube in several useful orientations.

Side Mounting Holes - These 10-32 holes allow the gearbox to be mounted on top of structural components without obstructing the front of the gearbox.

Threaded Assembly Holes - The screws holding the gearbox together thread into these holes to clamp the gearbox stack together.

Input Spline - Accepts torque from the last gear stage while being easy to insert and remove.

Alignment Tabs - Alignment features that engage with the alignment notches on the last stage. The directional nature of the alignment features prevents the user from assembling any gearbox components backwards.

MAXPlanetary MAXSpline Output Coupler

The MAXPlanetary MAXSpline Output Coupler (REV-21-3630) provides a compact and reliable way to interface a MAXPlanetary Gearbox’s 1/2 inch hex output with MAXSpline Shaft systems.

One side of the coupler accepts up to 0.47 inch of 1/2 inch hex shaft and uses a #10-32 screw that threads into the shaft end to lock it in place. The opposite side is machined for MAXSpline Shaft and provides 0.5 inch of engagement, secured using a removable two piece clamping collar tightened by two M3 socket head screws. The collar can be opened or removed without fully disassembling the system, making assembly and maintenance easier while ensuring strong, consistent shaft retention

Additional Input Coupler Options

8mm Keyed Input Coupler Kit (REV-21-2108) - Compatible with NEO Vortex, NEO V1.1, NEO 550 and CIM motors.

1/2in Hex Input Coupler (REV-21-2110) - Compatible with 2 Motor Gearbox - Through Bore and the MAX 180 Degree Gearbox, all designed to drive the MAXPlanetary

14T Spline Input Coupler (REV-21-2124) - Compatible with Falcon 500 and other 14T spline motors.

15T Spline Input Coupler (REV-21-2138) - Compatible with the SplineXS (Kraken and Minion) shaft spline, and other motors that have a 15T output.

• All 10-32 Screws used for Assembly and Mounting

• 10-32 Face Mounting Holes on a 2in Bolt Circle with 2 Orientations

• 2in Gearbox Height

  • Gearbox does not protrude above or below common FRC structural tubes

  • Output shaft stays on 1.0in pitch when the gearbox is mounted using the side holes

• Side Mounting Holes are on a 0.5in pitch regardless of number of stages

MAXPlanetary Cartridge Ratings

Static Load Ratings

The following torque measurements are for a static load condition. The torque values listed are for the output of the stage.

2:1 Cartridge Specifics

The MAXPlanetary 2:1 Cartridge (REV-21-2140) is designed for lower torque applications. Due to its lower failure rating, it should generally be placed closest to the input or motor in a multi-stage MAXPlanetary stack. It is ideal for intakes and faster mechanisms that need a small or specific amount of reduction, while keeping the flexibility to quickly swap cartridges and adjust the total ratio.

Cartridge Configuration

The following chart shows which gear cartridge configurations are allowable with different motors. Cells shown in GREEN are allowed and cells shown in RED are not allowed.

REV Motors

Other Motors

MAX 90 Degree Gearbox

Static Load Rating

Gearbox ultimate strength - Failure at 180 NM +/- 5%

The MAXPlanetary is a modular planetary gearbox designed for use with NEO-class motors and is optimized for torque density. By following these tips and tricks, you can ensure that your gearbox is assembled properly and functions efficiently. With the help of this guide, you will be able to assemble your MAXPlanetary gearbox with confidence and ease.

Recommended Order of Assembly

Follow the guide and install the MAXPlanetary 1:1 Brake Cartridge in your gearbox just like you would a gear cartridge. There are two places you can place your Brake Cartridge:

• Before Gear Reduction (Closest to Motor): This is the recommended assembly. This will decrease the shock loading done to your Brake Cartridge and increase its longevity.

• After Gear Reduction (Furthest from the Motor): This will decrease the shock loading affecting your gear cartridge(s) and is only recommended for high gear ratio applications.

To help teams properly align their Bevel Gear while assembling the MAX 90 Degree Gearbox we developed an Assembly Wedge tool. This tool can be 3D printed and reused to assemble multiple MAX 90 Degree Gearboxes.

Begin this process after Step 8 of the

1) With all screws in the MAX 90 Degree Gearbox installed slightly loose, insert an Assembly Wedge on either side of the gearbox ensuring the flat side of the wedge is in contact with the bottom plate.

2) While applying pressure to both Assembly Wedges, tighten the screws in the MAX 90 Degree Gearbox on alternating sides. Use the image below as a guide for tightening the screws.

3) Once all of the screws are secure, remove the Assembly Wedges and spin the gearbox to ensure it moves smoothly.