REV ION was created to minimize the required tools, hardware, and cost to build a robot. To accomplish this the REV ION System has standardized the following throughout its products:

#10 Clearance Holes

• All hardware is #10-32 sized

• Any tapped holes are #10-32

• Can use 3/16in rivets

1/2 in Hole Pitch

• Linear pattern or grid on structural components

• Radial pattern on circular components

• Some circular components also have the linear pattern for ease of attaching to structure

• Combined with MAX Spline to form the MAX Pattern

1/2 in Rounded Hex Shaft

• 13.75mm diameter rounded corners for ease of assembly in bearings

• Fits standard 1.125in OD Bearings

Fractional Axial Width

• Components together along a shaft always have a total width on a fractional interval

Tackling the challenges of FRC requires rapid iteration, multiple revisions and adaptation to the games challenges. Recognizing that not all teams have access to the same equipment or resources, we created REV ION to enable all teams to be competitive. REV ION is a system of mechanical and electrical components that are perfectly compatible with each other, allowing for complex robot designs without the need for large budgets or extensive manufacturing resources. With just basic tools, teams can build affordable, competitive machines, while preserving the ability to infinitely re-configure and iterate on their designs.

We built the REV ION mechanical system around the MAXSpline shape. This unique shape allows us to do things like combine a bearing support with a torque transfer feature for unrivaled configurability of motion components. We've also created the MAX Pattern, this pattern features the MAXSpline with an array of #10 clearance holes on either side. This pattern frees teams from cutting and drilling with easy installation of bearings for different live axle applications, as well as correct center-to-center distances for simple 1:1 power transmission with #25 chain or RT25 belting.

REV ION includes 300+ new and existing products that work within the existing FRC ecosystem, while introducing new features and functionality not currently available to teams. To see how ION can help with your next build, look for the bright blue ION logo next to compatible products on our website.

If you have any questions, please reach out to our support team via email: support@revrobotics.com

With the release of the REV ION Build System, the team at REV Robotics wanted to create a resource that introduces you to some of the basic components and techniques used within the FIRST Robotics Competition. Included in this guide are tips and tricks for building sturdy structures, how to transfer motion, and more!

The majority of a robot’s structural elements can be divided into two main categories:

• Extrusion

  • Patterned

  • T-Slot

  • Plain Stock

• Brackets

  • Motion

  • Structure

Structure Basics

All REV ION structural components are #10 hardware compatible.

MAXTube with MAX Pattern vs. 1in Extrusion

Fixed pitch based systems, like the MAX Pattern on MAXTube, have a set pattern of holes to use for mounting; everything that is attached is spaced on a multiple or a set fraction of the standard pitch.

In contrast, the 1in Extrusion System allows for flexible mounting positions along its slots. Simply slide any brackets that need to be mounted into the appropriate slot and adjust to the desired position. Because there is no fixed pitch, you can have the bracket in an infinite number of positions along your 1in Extrusion.

We believe that the easier it is to adjust your design, the easier it is to iterate and improve that design.

MAXSpline Brackets

In the REV ION Build System, motion brackets are referred to as MAXSpline Brackets because within the ION System, the MAXSpline shape is the core to transmitting motion. The major distinguishing feature of MAXSpline brackets are a MAXSpline bore, or a full MAX Pattern to support bearings and MAXHubs.

MAXSpline Bracket Specifications

• Material: Aluminum 5052

• Weights:

  • MAXSpline Bracket - Stacked: 35g (0.08lbs)

  • MAXSpline Bracket - Offset Mount: 91g (0.20lbs)

  • MAXSpline Bracket - Parallel Top Mount: 49g (0.11lbs)

  • MAXSpline Bracket - MAX Pattern T: 39g (0.09lbs)

Application Examples

MAX Pattern T Brackets

MAX Pattern T Brackets are ideal for creating a perpendicular joint of MAX Pattern MAXTube, as seen in the example below:

Alternatively, the two MAXSpline openings allow for unique gearbox mountings, such as with the MAX 90 Degree Gearbox as shown here:

Parallel Top Mount Bracket

The Parallel Top Mount Bracket can be used to provide support to the end of a shaft that may be cantilevered otherwise:

Offset Mount Bracket

The Offset Mount Bracket is perfect for allowing a motor to be mounted parallel to the axis of a MAXTube:

Stacked Bracket

The extra row of holes on the Stacked Bracket can be used to tile the MAXSpline pattern on a MAXTube in 2D, keeping the holes and the spline on pitch with the mounting tube. The Stacked Bracket is recommended when the goal is to offset a motor from a tube while wanting to remain on pitch with the original tube spline openings.

#10 Hardware Basics

Hardware Specifications

Button Head Socket Cap Screws

#10-32 Socket Hex Cap Screws

Standoffs

Structure brackets are designed to secure pieces of structure together at varying angles. There are different hole patterns available to accommodate the different extrusion types and patterns. In the REV ION Build System, structure brackets are any bracket that does not have a MAXSpline Bore.

Bracket Specifications

• Material: Aluminum 5052

• Thickness: 3mm (0.118in)

• Grid Pattern: 5mm (0.196in) holes on 0.5in grid

1in Brackets

3-4-5 Brackets

Create a sturdy triangle with our 3-4-5 Brackets to support your robot. When using 3-4-5 Brackets any 3 lengths of tube that make a 3-4-5 triangle will allow the holes to line up with the brackets and for the holes to stay on pitch relative to one another.

There 3-4-5 Brackets come in both external and internal versions. Both brackets form the same structure of a 3-4-5 triangle, it is just secured in different places.

Full Structural Brackets List and Weights

What is MAXComposite?

MAXComposite is made from self-reinforced polypropylene (SRPP), a pure thermoplastic material combining two molecular weights of polypropylene with different melting points.

During production, polymer chains are stretched and aligned into individual sheets, which are stacked and heat pressed under precisely controlled temperature, time, and pressure. This causes only the lower melting point polypropylene to bond, forming a matrix that secures the unmelted fibers (thus “self-reinforced”). The result is an exceptionally strong and rigid sheet with significantly higher strength than standard polypropylene.

MAXComposite is available in 0.1-inch and 0.2-inch thicknesses with sheet sizes of 47 by 23 inches. MAXComposite is 25% lighter than polycarbonate and impervious to Loctite, making it a durable and lightweight choice for various mechanisms and builds.

How to Use

Prototyping & Test Cuts

To reduce material waste and optimize designs, it is highly recommended to prototype using similar thickness materials such as 5mm (0.2-inch) underlayment or plywood before committing to MAXComposite.

Before cutting large parts, perform:

• Small test cuts with simple shapes to dial in laser or CNC settings.

• Critical tolerance tests, such as press-fit bearing holes or shaft clearances, to ensure accuracy.

Cutting & Fabrication

Laser Cutting

CO₂ laser cutting is the most effective method for precise fabrication. Proper laser settings are essential to achieve clean cuts without excessive melting or rebonding. The laser also seals the edges, preventing delamination. A higher flow air assist is recommended for best results. Ensure adequate ventilation as moderate smoke is produced during cutting.

Recommended Laser Cutting Settings (Based on a 100W CO₂ Laser):

• 0.2-inch sheets: 90-100% power, 5-10 mm/s speed (lower-powered lasers may require slower speeds)

• 0.1-inch sheets: 90-100% power, 20-25 mm/s speed (adjust speeds accordingly for lower-powered lasers)

Manual Cutting Methods

For resizing sheets to fit laser cutter beds, conventional tools such as table saws, bandsaws, or jigsaws can be used. However, be cautious of overheating and rapid air cooling, which may cause jamming in high-speed tools.

Processing Techniques:

• Table saw / Circular saw – effective for straight cuts and resizing for laser beds

• Jigsaw – useful for intricate or curved cuts or quick edits

• Bandsaw - slightly more controlled cuts than a jigsaw, but may not remelt edges

• Edge remelt techniques – reapplying heat to edges can help prevent delamination

Fitment & Finishing

Testing & Fitment

Before cutting larger parts, test fitment for bearing presses and hardware clearance. On our laser, a 1.1-inch diameter hole results in a snug arbor press fit for a rounded hex bearing.

Finishing Techniques

Some melted plastic may accumulate on the back of cut parts. Consider which surfaces need to remain smooth and use the following techniques for cleanup:

• Sanding

• Deburring tools

• Knife trimming

Note: Keep edges slightly melted together to prevent delamination.

Drilling & Adhesion

• Drilling: Sharp drill bits work for additional holes, and hole saws or jigsaws are effective for non-precision cuts.

• Adhesion: Due to polypropylene’s low surface energy, most adhesives do not bond well. Stickers and graphics require large surface areas, and for aesthetic purposes, you can mask and paint MAXComposite using plastic primers and paints.

CNC Machining

CNC Routing Considerations

While CNC machining is possible, CO₂ laser cutting provides the best results. If CNC routing is necessary, compression bits and proper workholding are critical.

Best CNC Machining Practices:

• Use a compression bit for optimal edge quality.

• Secure material with a vacuum table or screw it into a spoil board.

• Maintain a slight melt on edges to prevent delamination.

Tested CNC Settings:

• 1/8-inch compression bit

• 18,000 RPM spindle speed

• 108 in/min feed rate (0.003 inches per tooth)

Bending MAXComposite

Heat Bending Guidelines

MAXComposite can be heat-formed best using fixturing at 230-240°F. Avoid exceeding 250-260°F + to prevent degradation. Polypropylene melts at 320°F, so staying within the recommended range ensures proper bending without compromising strength.

For best results, use a heat source such as a strip heater or heat gun, applying even heat across the bending area. Secure the part in a bending jig immediately after heating to achieve the desired shape and prevent warping.

Chemical Resistance

MAXComposite is made entirely of polypropylene blends, making it highly resistant to chemicals. It remains unaffected by:

• Threadlockers (e.g., Loctite)

• Solvents (e.g., acetone)

This chemical resistance ensures that builds using Loctite remain secure and durable, even in the most intense competitions.

Best Practices & Recommendations

General Guidelines:

• Prototype with plywood to reduce material waste.

• Test laser settings on small cuts before full-scale production.

• Ensure proper ventilation when laser cutting.

• Use proper tools to maintain material integrity.

• Remelt edges slightly after cutting to prevent delamination.

• For CNC machining, prioritize compression bits and stable workholding.

By following these best practices, MAXComposite offers exceptional strength, weight savings, and fabrication ease, making it an ideal choice for a variety of applications.

MAXHubs

One of the oldest and least used shaft types is a D-shaft - a round shaft with one flat side that makes a D shape. To transmit motion with a D-shaft, shaft collars and motion components are secured to the flat side of the shaft using a set screw. Transferring torque through a set screw can cause failure in hightorque applications, and the set screws require re-tightening under the best of circumstances, so this method is generally not recommended

Another shaft type commonly found on motors and gearboxes are Keyed Shafts. These consist of two parts: a round shaft with a groove called a keyway, and a key that fits into that groove. Components attached to keyed shafts will also have a keyway, as the key is how torque is transferred from the shaft.

Shafts

MAXSpline Shaft

1/2in Rounded Hex Shaft

1/2in Hex Shaft Adapters

Convert different output types to 1/2in Hex Shaft to interface with the REV ION Build System using our different 1/2in Hex Shaft Adapters.

UltraPlanetary 1/2in Hex Adapter

8mm to 1/2in Hex Adapter

Spacers

MAXSpline Spacers

MAXSpline Spacer with MAX Pattern

1/2in Hex Shaft Spacers

8mm Shaft Spacer

#10 Spacers

Collars / Shaft End Screw

Transmitting Motion is the act of getting motion from one part of the robot to another using shafts, sprockets, gears, etc.

Transforming Motion is the act of changing the turning force (torque) and speed. Torque and speed are inverse to each other, meaning when one increases the other decreases. Several of the same components that transmit motion are also used to transform motion (sprockets and chain, belts and pulleys, and gears).

The core component to transmitting motion on a robot is a shaft. They come in many shapes and styles, but the goal of each shaft is to transmit motion to other components

One of the main components in transmitting motion in the REV ION Build System is 1/2in Hex (hexagonal, six sided) shape. 1/2in Hex is featured in components where a MAXSpline is too large or when motion needs to be directly transmitted to a 1/2in Hex shaft. 1/2in Hex shafts are available in a number of different lengths and can be cut to length if needed.

Another important shape for transmitting motion in the REV ION Build System is the MAXSpline. This shape is incorporated into the other main motion components such as: MAXHubs, sprockets, gears, wheels, pulleys, and MAXSpline shaft.

The two primary systems used for transmitting motion in the REV ION Build System are gears and sprockets with chain.

Dead Axle Tube - 3/4in

What is a Dead Axle?

A Live Axle is an axle that transmits torque to a wheel. This can be done through a 1/2in hex hub, gear, pulley, or sprocket. In a live axle assembly, the axle will rotate along with the wheel. Live axles are commonly used in drivetrains or as a flywheel.

In comparison, a Dead Axle is an axle that only supports the wheels and does not move. Generally, bearings are used to support the wheel on the dead axle so it can spin freely. Dead axles remain stationary while the supported wheel is in motion. Some applications include free-spinning intake rollers and non-powered drivetrain wheels.

Application Example

Bushing

Endcaps

Flanged Bearing

Needle Bearing

Bearing Blocks

Bearing Retaining Plate

• Material: Glass-filled nylon

• Weight: 3g (0.01lb)

• Compatible with MAX Pattern

• Uses #10 screws or 3/16in rivets

• Compatible with ION bearings or bushings

The bearing retaining plate can be aligned to sit parallel or at an angle along the MAXTube.

Sprockets and Chain are ideal for transmitting motion over long distances. A chain consists of a continuous set of links that ride on the sprockets to transmit motion. The two most commonly used sizes of chain in FIRST Robotics Competition are #25 and #35. When choosing between chain sizes, it is important to consider the pitch of the chain and the weight and forces that your mechanism will be experiencing. The REV ION Build System is designed around #25 chain using compatible #25 sprockets.

Sprocket Basics

Sprockets are rotating parts that have teeth and can be used with a chain and another sprocket to transmit torque. Sprockets and chain can be used to change the speed, torque or direction of a motor. For sprockets and chain to be compatible with each other, they must have the same thickness and pitch.

ION Sprockets

Anatomy of a Sprocket

The most common and important features of a sprocket are called out in the figure below.

Anatomy of Chain

Roller chain is used to connect two sprockets together and transfer torque. Roller chain is made up of a series of inner and outer links connected together which forms a flexible strand.

Using Sprockets and Chain as a Powertrain

Transforming the torque and speed of the motion is accomplished by changing the size of the sprockets.

A sprocket size ratio is the relationship between the number of teeth of two sprockets (input and output). In the image below, the input sprocket is a 15 tooth sprocket and the output is a 20 tooth. The sprocket size ratio for the example is 20T:15T. The ratio in size from the input (driving) sprocket to the output (driven) sprocket determines if the output is faster (less torque) or has more torque (slower).

Chain Tension

In order for sprockets to work effectively, it’s important that the center-to-center distance is correctly adjusted. The sprocket and chain example with the red 'X', in the image below, may work under very light loads, but they will certainly not work and will skip under any significant loading. The sprockets in this example are too close together so chain is loose enough that it can skip on the sprocket teeth. The sprockets, with the green check mark, are correctly spaced which will provide smooth reliable operation.

Sprocket and Chain Physics

Sprockets are one common way to transmit power and change the output torque or speed of a mechanical system. Understanding these basic concepts is required to make optimized design decisions. This section will briefly cover the definition of these concepts and then explain them in relationship to basic sprocket and chain designs.

Chain Drive

Selecting sprockets with different sizes relative to the input sprocket varies the output speed and the output torque. However, total power is not effected through these changes.

Sprocket and chain is a very efficient way to transmit torque over long distances. Modest reductions can be accomplished using sprockets and chain, but gears typically provide a more space-efficient solution for higher ratio reductions.

Sprocket Ratio

When a larger sprocket drives a smaller one, for every rotation of the larger sprocket, the smaller sprocket must complete more revolutions, so the output will be faster than the input. If the situation is reversed, and a smaller sprocket drives a larger output sprocket, then for one rotation of the input, the output will complete less than one revolution- resulting in a speed decrease from the input. The ratio of the sizes of the two sprockets is proportional to the speed and torque changes between them.

The ratio in size from the input (driving) sprocket to the output (driven) sprocket determines if the output is faster (less torque) or has more torque (slower). To calculate exactly how the sprocket size ratio effects the relationship from input to output, use the ratio of the number of teeth between the two sprockets.

Compound Reduction

Some designs may require more reduction than is practical in a single stage. The ratio from the smallest sprocket available to the largest is 64:16, so if a greater reduction then 4x is required, multiple reduction stages can be used in the same mechanism which is called a compound gear reduction. There are multiple gear or sprocket pairs in a compound reduction with each pair linked by a shared axle. When using sprockets and chain in a multi stage reduction, it’s very common to use gears for the first stage and then use sprockets and chain for the last stage. The figure below is an example of a two-stage reduction using all gears, but one of the pairs could be replaced with sprockets and chain. The driving gear (input) of each pair is highlighted in orange.

Reduction is calculated the same for gears and sprockets based on the ratio of the number of teeth. To calculate the total reduction of a compound reduction, identify the reduction of each stage and then multiply each reduction together.

Where:

• CR is the total Compound Reduction

• Rn is the total reduction of each stage

Using the image above as an example, the compound reduction is 12:1.

For any gear system, there are a limited number of gear and sprocket sizes available, so in addition to being able to create greater reductions using compound reductions, it is also possible to create a wider range of reduction values or the same reduction of a single stage, but with smaller diameter motion components.

Spacing and Center to Center Distances

Chain Loops can be used with ION Sprockets and structure featuring the MAX Pattern. Any 1:1 ratio will have the correct center-to-center distance for a properly tensioned chain, without the need for tensioning bushings. To calculate how many links you will need, multiply the center-to-center distance by eight, and add the number of teeth on one sprocket.

• Links of #25 chain = (Center-to-center Distance x 8) + Teeth in one sprocket

If a ratio other than 1:1 is needed when using the REV ION Build System, use our Ratio Plates to accommodate for the change in center-to-center distance. An ION Ratio Plate provides an offset from the standard MAX Pattern pitch that creates the center-to-center distance.

Spacing

In order for sprockets to work effectively, it’s important that the center-to-center distance is correctly adjusted. The sprocket and chain example with the red "X" in the image below may work under very light loads, but they will certainly not work and will skip under any significant loading. The sprockets in this example are too close together, so the chain is loose enough that it can skip on the sprocket teeth. The sprockets with the green check mark are correctly spaced, which will provide smooth and reliable operation.

Gear Basics

Gears have teeth that mesh with other gears in order to transmit torque. Gears can be used to change the speed, torque (turning force), or direction of a motor’s original output. For gears to be compatible with each other, the meshing teeth must have the same shape (size and pitch). Gears are ideal for use in more compact spaces and are also used for changing the direction of rotation.

There are many different types of gears; one of the simplest and most commonly used is a spur gear, and that is the gear type used in the REV ION System. Spur gears consist of a disk with straight teeth projecting radially (outward from the center) and these gears will only mesh correctly with other gears if they are on parallel shafts.

Anatomy of a Spur Gear

20DP Pocketed Gears

Gear Alignment Mark

Sometimes in a design it may be desirable to stack together multiples of the same gear on a shaft to increase the load carrying capacity of the gears. In the case where the number of teeth on the gear is not divisible by six, because of how they are oriented when put onto the hex shaft, the teeth may not be aligned between the two gears. To ensure all of the gears are clocked the same way, use the alignment shaft notch to put all the gears on the shaft with the same orientation.

Using Gears as a Powertrain

Meshing two or more gears together is known as a gear train. Selecting the gears in the gear train as larger or smaller relative to the input gear can either increase the output speed, or increase the output torque but the total power is not affected.

A gear ratio is the ratio of the sizes of two gears. For instance, in the image below, the input gear is a 15 tooth gear and the output gear is a 72 tooth gear. So, the gear ratio is 72T:15T. The ratio in size from the input (driving) gear to the output (driven) gear determines if the output is faster (less torque) or has more torque (slower). The gear ratio is proportional to the speed and torque changes between them.

In the image above, the 15 tooth input gear is rotating clockwise. As the input gear rotates, it pushes down on the output gear where the teeth are meshed. This action transmits the motion to the output gear, but forces the output gear to rotate in the opposite direction of the input gear.

Gear Spacing

In order for gears to work effectively, and not become damaged, it’s important that the center-to-center distance is correctly adjusted. The gears in DETAIL A of the figure below may work under very light load, but they will certainly not work and will skip under any significant loading. The gears in that example are too far apart, and the teeth of each gear barely contact each other. The gears in DETAIL B are correctly spaced and will provide smooth and reliable operation.

Creating a loop of chain requires breaking off the correct number of links by removing a specific chain pin and joining the ends together. Chain can be broken using many methods, including a Chain Tool or various steel cutting blades, like a dremel. Once you have counted the number of links necessary for your application, the chain can be joined using a master link or by replacing the chain pin.

#25 Chain Tool Basics

Kit Contents

• 1 Chain Tool Block

• 2 Set Screw Mandrels

• 1 Depth Guide Screw

• 1 Cup Point Set Screw

• 1 4mm Allen Wrench

Manipulating Chain

In almost all applications, chain links are connected to form a loop. While chain can sometimes be purchased in specific length loops, it is more common and economical to buy chain by the foot and make custom loop lengths to fit the application. It’s recommended to use a specialized tool, a chain breaker, to cut chain into desired lengths to prevent accidental damage.

Chain breakers do not actually cut the chain; instead, they are used to press out the pins from an outer link. After the pins have been removed, the chain can be separated, leaving inner links on both ends of the break.

Using the Chain Tool

Using Master Links

Resetting Chain Pins

Linear actuators are a device that creates motion in a straight line, as opposed to the rotational motion of a motor. It consists of a motor, a lead screw, and a moving rod or shaft. The rotation of the motor turns the lead screw, this screw is threaded in a way that converts the rotational motion of the motor into linear motion, causing the rod or shaft to extend or retract. Linear actuators are commonly used in applications that require precise and controlled straight-line movement, such as climbing tasks, driving arms, actuating intakes, and deploying other diverse mechanisms. Their design allows for efficient, reliable, and smooth operation in various mechanical systems.

Linear Actuator - 12in Stroke

Specifications

Lead Screw Specifications

Motor Tables

NEO Vortex Brushless Motor

NEO Brushless Motor V1.1

Ratio Plates

Each ratio plate is designed for the indicated sprocket or pulley combination and a loop of chain or belt that is the indicated length. For example, 56PL equates to a 56 link loop of #25 chain or a 56 tooth RT25 belt.

• Alignment Markings show the intended direction for the run of chain/belt to have the correct spacing needed for the ratio.

• The ½ in Pitch Grid allows the Ratio Plate to match up with the desired MAXTube pattern used for the connected structure

• The shifted area marked by the white box allows for the mounting of a motor or bearing and the shaft setup at the denoted ratio spacing

Applications Examples

Standard MAXSpline, present in the MAX Pattern and MAX Tube, has 2in center to center spacing. This is designed for very convenient 1:1 ratios using #25 chain or RT25 belts which have a 0.25in pitch.

If you want to have more specific ratios on pitch (down the tube) you may run into issues due to belt or chain lengths being too loose or too tight due to the correct center to center distance not being a multiple of 2in. To allow for a few specific ratios that teams may want to use, Ratio Plates are designed to give you that very specific spacing while still mounting to the MAX Pattern of MAX Tube!

Ratios

(REV-21-2567-PK2) Ratio Plate - 2:1

• Designed for a 2:1 ratio using a 12T and a 24T sprocket/pulley

• The pitch needed for the belt or roller chain is 56 pitches (56 tooth RT25 belt, or roller chain with 28 links)

(REV-21-2574-PK2) Ratio Plate - 3:1

• Designed for a 3:1 ratio using a 16T and a 48T sprocket/pulley

• The pitch needed for the belt or roller chain is 72 pitches (72 tooth RT25 belt, or roller chain with 36 links)

(REV-21-2575-PK2) Ratio Plate - 4:1

• Designed for a 4:1 ratio using a 16T and a 64T sprocket/pulley

• The pitch needed for the belt or roller chain is 80 pitches (80 tooth RT25 belt, or roller chain with 40 links)

Onshape Examples

As seen in the Onshape example, generally three standoffs are used to mount the ratio plate to the MAXTube. One is in the middle towards the alignment markings pointing for direction and the remaining two stand on the opposite side to support the plate and allow clearance for the belts/chain.

NEO Vortex

Features

• High-resolution encoder

• Integrated motor parameter and calibration memory

• Through-hex bore with taper for numerous quick-change shafts

• No motor wires - reliable and robust docking connections for motor phases and sensor

• Dual sensor, direct contact winding temperature sensing

• 560KV (RPM per volt)

• 640 Watts (375 @ 40A)

• #10-32 threaded holes on a 2in bolt circle

• The motor and motor controller's silhouette fits behind a standard 2in rectangular tube

• 1/2in hex through-bore rotor compatible with any length hex shaft or application-specific Vortex Shafts:

  • 8mm keyed

  • Falcon compatible spline

  • MAXSwerve with integrated key

  • 7-tooth 20DP gear

  • MAXPlanetary input

  • Others to be announced

Motor Specifications †

NEO V1.1

Features

• Drop-in replacement for CIM-style motors

• Shielded out-runner construction

• Front and rear ball bearings

• High-temperature neodymium magnets

• High-flex silicone motor wires

• Integrated motor sensor

  • 3-phase hall sensors

  • Motor temperature sensor

New to NEO V1.1

• A tapped #10-32 hole on the end of the shaft, allowing teams to retain pinions on the shaft without using external retaining rings

• A tapped #10-32 hole on the back housing of the motor, making it no longer necessary to remove the motor housing to press pinions

• Additional holes on the front face of the motor for added mounting flexibility

Motor Specifications

NEO 550

The REV NEO 550 Brushless Motor runs a 0.12in output shaft which, when combined with its 550-style mounting features, allows for easy installation in many off-the-shelf gearboxes.

Its small size and weight make it easy to put power where you need it, whether that is on intakes, end-effectors, or other weight-sensitive mechanisms. However, keep in mind that this motor has a lower thermal mass than a NEO, CIM, or Mini CIM, and thus it may not be ideal for some drivetrain applications.

Features

• Mounting features match other 550 series DC motors

• Front and rear ball bearings

• High-temperature neodymium magnets

• High-flex silicone motor wires

• Integrated motor sensor (3-phase hall sensors)

• Motor temperature sensor

Motor Specifications

Documentation Links

Servo Power Module

The REV Robotics SRS Programmer is the key to unlocking all the smart features of the Smart Robot Servo (SRS). Switching between continuous rotation, standard servo, and custom angular modes is easy as pressing a button. The SRS Programmer can not only program the SRS, but it is also acts as a standalone servo tester for any standard RC servo.

Servo Power Module

Most wheels used in FIRST Robotics Competition can be divided into four categories; Standard, Omni, Mecanum, and Compliant. One element to consider when choosing a wheel is the bore size, and if you will need any additional hubs to convert your wheel to the needed input or output.

Most sizes of ION wheels feature a MAXSpline bore that can fit standard 1.125in OD bearings or easily be adapted to other bores using MAXHubs. Smaller wheels feature 1/2in hex bore. Larger sizes of ION Traction, Grip, and Omni Wheels have spokes with a bolt circle of #10 clearance holes patterned outward at 1/2in pitch. They also have a 3/8in-wide nut groove that eliminates the need for a wrench when utilizing the holes on the spokes.

Wheel Basics

Belts and pulleys are a great, lightweight option for building a smooth-running mechanism. They are very similar to chain and sprockets, with the belt replacing chain and pulleys replacing sprockets. The biggest difference is that belts are a set size and can not be adjusted, so you lose some flexibility in spacing options. If you want to change the spacing of your pulleys or use a different size pulley to increase speed, you will likely need a different sized belt.

In the REV ION Build System, we created a new standard of belt called RT25. Unlike many common metric belt standards, RT25 Belts haves a 1/4in pitch just like #25 chain. With this pitch, both RT25 belts and #25 chain work natively within the ION build system. Since they are both on a 1/4in pitch, they can be swapped out 1:1 for rapid prototyping and iteration of designs. The pitch compatibility with MAX Pattern also makes it easier to swap in different belt lengths when you want to make changes. These belts are comparable in strength to the belts that teams are accustomed to using while working on the same pitch as the ION Build System.

Servo Basics

Common servo motors take a programmed input signal range and map that to an angular range. For example, for a servo with a 270° range, if the input range was from 0 to 1 then a signal input of 0 would cause the servo to turn to point -135°. For a signal input of 1, the servo would turn to +135°. Inputs between the minimum and maximum have corresponding angles evenly distributed between the minimum and maximum servo angle.

Servo Accessories / Adapters

REV Robotics Servo Adapters fit 25T spline servos like the REV Robotics Smart Robot Servo. In addition to the variety pack of generic servo horns which come with the Smart Robot Servo, there are five other custom servo adapters which make using servos with the REV ION Build System easy.

Gearboxes are a very common way to transform motion in FIRST Robotics Competition. They are generally compact and modular, able to be mounted on your robot wherever they’re needed. Some have fixed gear ratios, and some can be easily changed for the needed application.

A popular style of gearbox is the adjustable, modular, planetary gearbox. In this kind of planetary gearbox, cartridges of different gear ratios are stacked to create an overall reduction. This is a fantastic option for teams to prototype with because they can quickly change the gear ratio without needing to redesign the entire mechanism.

2 Motor Drivetrain Gearbox Through Bore

2 Motor Gearbox - Through Bore

MAXPlanetary System

UltraPlanetary System (NEO 550)

Flap Wheels are used for intakes and conveyor systems to pick up irregular game pieces, playing a similar role to compliant wheels. ION Flap wheels feature cut marks every 3.2mm on the flaps for consistent cutting, allowing for versatility and adaptability for unique game pieces. The ION Flap wheels have a solid 1/2in Hex Hub molded into the wheel making sure more power is driven by the wheel. These wheels come in three different durometers, outlined below. As the tread durometer increases the compliant flap gets harder which will change traction, wear, and compliance of the flap.

Specifications

Durometer Specs

Application Examples

On the 2024 REV ION FRC Starter Bot, the flap wheels on the intake aid in grabbing the CRESCENDO game pieces to be secured for the launcher.

The flap wheels spin while the intake is lowered to sweep game pieces into the compliant wheel rollers providing a further reach.

Features

• Allows user to adjust gear ratio by changing pinion and cluster gear (12:60, 18:54, 24:48, or 36:36)

• Output shaft is 1/2in Hex through bore

• Output gears have MAXSpline bore

• Motor Plate contains 2 pairs of 2in pitch #10-32 tapped holes for mounting the Through Bore Encoder

• Output Plate has array of holes for mounting to structure, as well as mounting an input to MAXPlanetary

• 5:1 ratio can be micro-adjusted by swapping a 12T pinion for an 11T or 10T

Base Kit Contents

Ratio Gear Bundle Contents

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

MAX 90 Degree Gearbox Assembly Wedge

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.

Using the Assembly Wedge

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.

Features

• Adjustable speed based on pinion gears

• Adjustable wheel size based on second stage gear pairs

• Mountable in a variety of options to allow for chain-in-tube and chain/belt outside tube designs

Kit Contents

MAXPlanetary System Overview

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 three 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.

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.

MAX 90 Degree 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 3:1 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

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 prevent 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.

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 prevent the user from assembling any gearbox components backwards.

MAXPlanetary System

Static Load Ratings

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

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 REV Robotics MAXPlanetary System includes the following features:

• Three different, self-contained gear ratio cartridges providing twenty-seven gear ratios ranging from 3:1 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

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 prevent 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.

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 prevent the user from assembling any gearbox components backwards.

• 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

MAXSwerve Code Templates

Below are two GitHub Repositories for template projects that will control an FRC swerve drivetrain built with REV MAXSwerve Modules.

Note that this is meant to be used with a drivetrain composed of four MAXSwerve Modules, each configured with two SPARK MAXs, a NEO as the driving motor, a NEO 550 as the steering motor, and a REV Through Bore Encoder as the absolute turning encoder.

Adjusting Slew Rate Parameters

Within the Constants file for both the Java and C++ MAXSwerve Templates, there are three variables that your team can tune for your robot's Slew Rate needs. To determine the default values we loaded a test MAXSwerve Drivetrain to approximately 140lbs (Including bumpers and battery) and tuned the parameters until we found values that made the MAXSwerve Wheels last the longest amount of time.

DirectionSlewRate

DirectionSlewRate is the most important parameter for reducing MAXSwerve Wheel failures. Lower values limit the rate of change of the direction of the robot. This avoids high-speed J turns that put destructive side loads on the wheels. Note that direction changes faster than the slew rate are allowed at lower speeds. The value here is the slew rate at 100% linear speed.

MagnitudeSlewRate

The MagnitudeSlewRate, or acceleration, in the linear direction. Generally, adjustments to the direction slew rate should be applied here as well (i.e. both should be increased or both should be reduced).

RotationalSlewRate

RotationalSlewRate is not a major contributor to wheel wear but may help smooth other motions out. If the robot has to do a lot of spinning due to defense or a particular style of mechanism, reducing this could help reduce tread wear.

// Driving Parameters - Note that these are not the maximum capable speeds of
// the robot, rather the allowed maximum speeds

public static final double kMaxSpeedMetersPerSecond = 4.8;
public static final double kMaxAngularSpeed = 2 * Math.PI; // radians per second

public static final double kDirectionSlewRate = 1.2; // radians per second
public static final double kMagnitudeSlewRate = 1.8; // percent per second (1 = 100%)
public static final double kRotationalSlewRate = 2.0; // percent per second (1 = 100%)

// Driving Parameters - Note that these are not the maximum capable speeds of
// the robot, rather the allowed maximum speeds

constexpr units::meters_per_second_t kMaxSpeed = 4.8_mps;
constexpr units::radians_per_second_t kMaxAngularSpeed{2 * std::numbers::pi};

constexpr double kDirectionSlewRate = 1.2;   // radians per second
constexpr double kMagnitudeSlewRate = 1.8;   // percent per second (1 = 100%)
constexpr double kRotationalSlewRate = 2.0;  // percent per second (1 = 100%)

MAXSwerve Template Changelog:

V2023.1

• Added a configurable rate limiting system to prevent excessive loads from causing premature wheel failure.

The following images will describe a rating system we have developed for determining if a MAXSwerve Wheel should still be used on your robot.

MAXSwerve Wheel V1 - Plastic Evaluation

Green Wheels

Okay to keep using this wheel because it is still in good shape. There is minor wear or damage to the tread but no signs of too much axial force or scrub.

Yellow Wheels

The affected wheel should be monitored closely because it is showing signs of wear that could lead to delamination of the tread. Please be sure to check the wheel again after your next match!

Red Wheels

Red Wheels need to be replaced right away and before the next match if possible. Delamination is very likely to occur with continued use beyond this state.

Quick Reference

Axial vs. Radial

In this section, we will describe different features of the MAXSwerve Wheel and wear patterns as Axial or Radial. Here are some descriptions of what these terms mean on a MAXSwerve Wheel.

• Radial - Describes features that occur radiating from the center of the wheel towards the tread

• Axial - Describes features that occur side to side along the wheel’s axle

Please see the table below for examples of wheels that demonstrate the criteria for each rating.

MAXSwerve Wheel V1 Evaluation Details

We recommend checking the following items before each match to ensure that your MAXSwerve Modules are ready to go!

Inspection Checklist

Please be sure to check all 4 MAXSwerve Modules on your robot for each list item!

• MAXSwerve Wheel wear is within the Green or Yellow range

  • No axial separation of the tread that shows the core's supports
• Forks are secure and screws are tight

• Bevel Gears are securely attached

• Wheel Hub bolts are fully screwed in

• Steering Gears and other greased components are free of debris; if any metal shavings or debris are found, clean thoroughly and reapply grease

• Axle Bolt is in place and secure

• UltraPlanetary Bolts (QTY 6 per module) are secure and thread locker has been applied

  • 4 bolts on the bottom of the MAXSwerve Module

  • 2 Bolts on the inside of the MAXSwerve Module

• Both Motors are securely attached

• Wiring is secure and nothing has become unplugged

  • Ensure the Steering NEO 550’s internal encoder and the Through Bore Encoder are both plugged into the steering SPARK MAX.
• Manually spin each wheel to ensure the motor key is securely in place and is not in contact with the encoder fork

• MAXSwerve Module's driving rotation and steering rotation move independently and do not affect each other

MAXSwerve Module Overview

Greasing Guide

Features

• Metal construction

• 3in wheel diameter

• Module mounting maximizes wheelbase footprint

• Compatible with NEO Brushless Motor or Falcon 500 (with replacement shaft)

• Azimuth driven by NEO 550 Brushless Motor & UltraPlanetary Gearbox

• All steel gears in drive powertrain

• Gear-driven azimuth drive

Specifications

MAXSwerve Resources

Drivetrains

Mechanisms

Panel/Cargo Intake from 2019 Deep Space

Power Cube intake from 2018 Power Up

Full Robots

1in Brackets

Showcases the 1in Bracket - 45deg by fastening MAXTube - 2x1 Tubes together via rivets

Showcases the 1in Bracket - 90deg by fastening MAXTube - 1x1 Tubes together via full length screws

Showcases the 1in Bracket - 90deg by fastening MAXTube - 2x1 Tubes together via screws and captured Nylon Lock Nut

Showcases the 1in Bracket - 135deg by fastening MAXTube - 2x1 with MAX Pattern Tubes together via screws and captured Nylon Lock Nut

Showcases the 1in Bracket - T-Shape by fastening MAXTube - 2x1 Light with Grid Pattern Tubes together via screws and captured Nylon Lock Nut

Dead Axle

Dead Axle interfacing with MAX Pattern

Dead Axle Interfacing with the 1x1in MAXTube Grid Pattern

MAX Pattern Structure

Shows how to mount an angled 1X1 Tube with a horizontal MAX Pattern Tube

Shows how to mount a vertical Max Pattern Tube backed against a horizontal MAX Pattern Tube

MAX Pattern Motion Interface

Shows how to mount a sprocket to a MAX Pattern Tube

Shows how to mount a MAXSpline Gear to a MAX Pattern Tube

Shows how to mount a 1/2in Hex Gear to a MAX Pattern Tube

Shows how to mount a pulley to a MAX Pattern Tube

MAXSpline Motion Interface

MAXSpline interfacing with multiple motion components

MAXSpline interfacing with a grip wheel

MAXSpline interfacing with a traction wheel

MAXSpline interfacing with a compliant wheel

MAXSpline interfacing with a omni wheel

MAXSpline interfacing with a gear

MAXSpline interfacing with a pulley

MAXSpline interfacing with a sprocket

MAXSpline Shaft

Showcases how to interface a MAXSpline to a dead axle in high speed applications

Showcases how to interface a MAXSpline to a dead axle in high load applications

Showcases how to interface a MAXSpline to a 1/2in hex axle

Power Train Mounting

Mounting a NEO Directly to a MAX Pattern Tube

Mounting a NEO driven MAXPlanetary to a MAX Pattern Tube

Mounting a NEO 550 driven UltraPlanetary to a MAX Pattern Tube

Mounting a Smart Robot Servo to a MAX Pattern Tube

Wheel Assemblies

Directly mounting a sprocket to a wheel in a dead axle application

Directly mounting a gear to a wheel in a dead axle application

Directly mounting a pulley to a wheel in a dead axle application

Back-to-back mounting of two traction wheels

Wheels

Interfacing a Traction Wheel with an Aluminum MAXHub

Interfacing a Traction Wheel with flanged bearings

Interfacing a Omni Wheel with an Aluminum MAXHub

Interfacing a Grip Wheel with a Plastic MAXHub

Interfacing a Compliant Wheel with a Plastic MAXHub

From simple joints to fully designed mechanisms, our Onshape CAD examples will help your team to get started planning out your robot using the ION Build System in no time!

The library of low complexity Onshape examples includes wheel assemblies, the use of MAX Pattern and MAXSpline, dead axles, and more!