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

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!

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

Brackets are used to join different parts of the robot together. Most brackets can be divided into two categories: Motion and Structure. Motion brackets help create strong attachment points for your motion components and any parts of your robot that move. Structure brackets are designed to hold pieces of extrusion together.

Bracket Basics

In the REV ION Build System, there are two major groupings of brackets: MAXSpline and construction. The major distinguishing feature of MAXSpline brackets is a MAXSpline bore or MAX Pattern to support bearings and MAXHubs. Construction brackets are essentially any bracket in the REV ION Build System that does not have a MAXSpline bore. Because the term construction bracket encompasses a broad range of REV ION products, it can be further subdivided as structural brackets and actuator brackets.

Structural brackets act as connectors between structural components. For example, these are the type of brackets you will want to use when connecting MAXTube and Extrusion elements. Actuator brackets on the other hand are intended to mount and support motors and servos.

Follow through the following sections to learn more about brackets:

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

The REV ION Build System's structural components are comprised of a collection of aluminum extrusions. This includes MAXTube, a family of rectangular tubes that are available in a variety of sizes, thicknesses, and hole patterns. MAXTube hole patterns are compatible with #10 Hardware and the MAXSpline. Our slotted 1in Extrusion comes in a 1x1in size and features t-slots that allow for brackets and other items to be adjusted to any position along the rail. MAXSpline Shaft is an extrusion with the same outer profile as the MAXSpline that provides a high strength shaft alternative where more torque is needed.

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.

With REV ION, we made it easy to calculate center-to-center distances for standard reductions along the fixed pitch. Gear reductions that add up to 80 teeth and 1-to-1 sprocket/pulley combinations will work by default. For ratios that don't fit on the fixed pitch, we have created Ratio Plates that feature an adjusted version of the MAX Pattern.

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

MAXSpline Brackets are compatible with the REV ION System and are designed to mount to pieces of 2x1in MAXTube - with MAX Pattern while maintaining proper pattern spacing.

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.

You can also use MAXSpline Brackets to mount motion components such as motors and pulleys, as seen below. A MAXPlanetary Gearbox fits perfectly on the 2in hole pattern of the Offset Mount MAXSpline Bracket (REV-21-2351).

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.

MAX Pattern Plates featuring the MAX Pattern: a MAXSpline surrounded by #10 clearance holes on a 1/2in pitch grid. The plates are available in various lengths, with the pattern repeating every 2in.

Differential Drivetrain Bumper Bracket Kit

The Differential Drivetrain Bumper Bracket Kit is designed to be a quick and convenient way to install FRC legal bumpers on the REV ION West Coast Drivetrain or an AM14U based drivetrain with included Bumper Adapters (REV-21-3067).

MAXTube Extrusion

is compatible with the REV ION System and is a strong extruded aluminum tubing (Aluminum 6061) that features positional hole patterns that make robot structures easier to build.

MAXTube comes in three extrusion profiles: 1x1in Tube, 2x1in Tube, and 2x1in Light Tube.

All 1in sides of the MAXTube extrusion have a nut groove inside to fit #10 nuts, making assembly easier by helping to retain nuts where a wrench can't reach.

MAXTube Hole Patterns

MAX Pattern

Some MAXTube features the MAX Pattern, combination of #10 holes in a 1/2in pitch grid and the MAXSpline bore every 2in. This repeats down the length of channel to mount bearings, MAX Hubs, shafts, brackets, and more.

Grid Pattern

2x1in MAXTube that features Grid Pattern has three rows of #10 holes on a 1/2in pitch. The Grid Pattern is ideal for rapidly prototyping structures with our 1in brackets.

MAXTube Available Sizes

1in Extrusion

The flexibility of T-Slot Extrusion makes using it a great option for builds that won’t fit on the pattern of your patterned extrusion. Teams are not locked into a pitch, so there are virtually infinite options for mounting other components. T-Slot Extrusion is also a great option for adding linear motion to your robot.

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

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

MAXSpline Shaft () is compatible with the REV ION System and is an extruded aluminum MAXSpline that provides a high strength alternative to 1/2in hex shaft that can interface with any REV ION system components. The inner diameter is 1in and can fit a Needle Bearing for dead axle applications.

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

MAXHubs

MAXHubs provide a way to transfer torque to a MAXSpline pattern from shafts of various shapes and sizes. Other MAXHub variants allow for different bores or structural patterns to populate within an existing MAXSpline. MAXHubs are available in plastic and aluminum.

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.

The ION Pivot Joint (REV-21-2395-PK2) can be used in numerous ways within the ION Build System. One example is a Pivot Joint being used as a bearing for a shaft to support a wheel, like in the picture below. Another example is a Pivot Joint being used as a hinge for a pivoting mechanism.

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

All REV ION Gears are 20DP, made of 4140 Steel, and pocketed to reduce weight. Our REV ION 20DP Gears (Product Family Page) come in a wide range of sizes and bores including MAXSpline, 1/2in Hex, and 1/2in Rounded Hex. Larger gears include #10 clearance hole patterns, 2in bolt circle, and MAXTube mounting pattern.

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.

Flanged Bearing

The Flanged Bearing (REV-21-1916) for 1/2in Rounded Hex is compatible with the REV ION System and provides a way of locating and supporting a 1/2in Rounded Hex Shaft while it rotates. The flange on the outer space of the bearing allows the bearing to be installed in a hole or MAXSpline with no other means of retention.

Needle Bearing

The Needle Bearing (REV-21-2386) with 3/4in ID and 1in OD, fits into MAXSpline Shaft (REV-21-2520) and is used for dead axle applications. Hold it in place securely using a 3/4in Needle Bearing Carrier (REV-21-2385).

Bearing Blocks

Bearing Retaining Plate

The Bearing Retaining Plate (REV-21-2286-PK10) is compatible with the REV ION System and is designed to securely hold bearings in place, ensuring that they remain stable and aligned during use.

• 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.

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

The below tables provide the mathematical performance possibilities, and assume 1:1 gearing and 100% vertical load. Cantilever load and gear reductions will change these numbers. We recommend using a lead screw calculator such as the AMB Robotics Calculator for Lead Screws to find the numbers for your application.

NEO Vortex Brushless Motor

NEO Brushless Motor V1.1

Gear Physics

Gears 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 which consider the trade-off between torque and speed for a system with a given power.

Gear Train

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.

Gear Ratio

When a larger gear drives a smaller one, for one rotation of the larger gear the small gear must complete more revolutions - so the output will be faster than the input. If the situation is reversed, and aa smaller gear drives a larger output gear, then for one rotation of the input the output will complete less than one revolution – so the output will be slower than the input. The ratio of the sizes of the two gears is proportional to the speed and torque changes between them.

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). To calculate exactly how the gear ratio effects the relationship from input to output, find the ratio for the number of teeth between the two gears. In the image below, the ratio of the number of teeth from the input gear to the output gear is 72T:15T which means the input needs to turn 4.8 rotations for the output to complete one rotation.

Idlers

What happens when a 45 tooth idler gear is inserted into the gear example? An idler gear is any intermediate (between input and output) gear which does not drive any output (work) shaft. Idler gears are used to transmit torque over longer distances than would be practical by using just a single pair of gears. Idler gears are also used to reverse the direction of the rotation of the final gear.

Regardless of the number or size of idler gears in the chain, only the first and last gear determine the reduction. Since idler gears do not change the gear reduction, the reduction in the example remains 72:15, but the direction of the output stage is now reversed from the previous example.

Idler gears are a good way to transmit power across distances in your robot. A common example of this is an all gear drivetrain. In this example the gears on the end are linked to the drive wheels and one of the center gears would be driven by a motor (not shown). The orange arrows indicate the relative rotation of each of the gears showing that the two wheels are mechanically linked and will always rotate in the same direction.

Because idler gears reverse the direction of rotation, it is important to pay attention to the number of gears in the drivetrain. In the picture below there is an even number of gears, and because of this the wheels will always spin in the opposite direction.

Compound Gearing

Some designs may require more reduction than is practical in a single stage. The ratio from the smallest gear available to the largest in the REV ION Build System is 80:10, so if a greater reduction than 8 is required, multiple reduction stages can be used in the same mechanism, and this is called a compound gear reduction. There are multiple gear pairs in a compound reduction with each pair of gears linked by a shared shaft. Below is an example of a two-stage reduction. The driving gear (input) of each pair is highlighted in orange.

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 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 gears.

Center-to-Center Distance

To ensure that you have a proper amount of gear teeth mesh, it is important to calculate the center-to-center distance in between your gears. You can do this by first calculating the pitch diameter (PD) of each gear using some combination of module (M), number of teeth (N), or outside diameter (OD).

• PD = M × N

• PD = (OD × N) / (N + 2)

• PD = OD - (2 × M)

Then, use the pitch diameters to calculate the center-to-center distance (CCD).

• CCD = ((PD1) / 2) + ((PD2) / 2)

Addendum Shifting

ION UltraPlanetary Bracket

The ION UltraPlanetary Face Mount Bracket (REV-21-2046) allows for easy mounting of our UltraPlanetary Gearbox to any of our MAXTube products. The plate features 2 x #10-32 tapped inserts for easy mounting on any structure.

Specifications:

• Material: Glass-Filled Nylon

• Weight: 6g (0.01lb)

MAXSpline Bracket - Motor Mount - Flat

The MAXSpline Bracket - Motor Mount - Flat (REV-21-2360) facilitates quick mounting of motors or gearboxes with a 2in bolt pattern to MAXTubing or structures. It includes a MAXSpline Bore for accommodating bearings, shaft integration, or other MAXSpline Bore-compatible components.

Specifications:

• Material: 5052 Aluminum

• Thickness: 3mm (0.12in)

• Motor Mounting Holes: #10-32 on 2in bolt circle

• Mounting Holes: 5mm (0.196in) holes on 0.5in grid

• Weight: 33g (0.073lb)

MAXSpline Bracket - Motor Mount - Bent

The MAXSpline Bracket - Motor Mount - Bent (REV-21-2361) offers similar functionality to the flat version but features a 90-degree bend on the mounting tabs for versatile positioning. It also includes a MAXSpline Bore for bearing and shaft integration or other compatible components

Specifications:

• Material: 5052 Aluminum

• Thickness: 3mm (0.12in)

• Motor Mounting Holes: #10-32 on 2in bolt circle

• Mounting Holes: 5mm (0.196in) holes on 0.5in grid

• Weight: 27g (0.060lb)

Universal Motor Bracket

The Universal Motor Bracket (REV-21-2804) is compatible with most motors or gearboxes, allowing rapid attachment to structures. It features 5mm (0.196in) holes on 0.25in pitch horizontal spacing for precise positioning without the risk of plate slippage. This bracket is ideal for quick problem-solving and efficient prototyping systems.

Specifications:

• Material: 6061 Aluminum

• Thickness: 4.76mm (0.188in)

• Length: 108mm (4.252in)

• Width: 63.5mm (2.5in)

• Mounting Holes: 5mm (0.196in) holes on 0.5in vertical and 0.25in horizontal grid

• Compatible with the following motors and accessories:

  • NEO 1.1, NEO 550, SPARK Flex/ NEO Vortex, MAXPlanetary, UltraPlanetary, Falcon 500, Kraken X60, Kraken X44, Minion, CIM/Mini CIM, 775pro/redline, MAX 90, MAX 180

• Weight: 70g (0.154lb)

MAXPlanetary Kraken X44 & Minion Adapter Plate

The MAXPlanetary Kraken X44 & Minion Adapter Plate (REV-21-4444) is designed with counterbored motor mounting holes and #10-32 tapped holes on a 2-inch bolt circle for seamless REV ION compatibility. Its compact footprint ensures a streamlined setup no matter if you are using it as an input for MAXPlanetary or mounting directly to MAX Pattern.

• Material: 6061 Aluminum

• Finish: Black Anodized

• Thickness: 9.5mm (0.374in)

• Motor Mounting Holes: #10 clearance

• Motor Hole Counterbore: 10mm (0.394in) diameter, 5mm (0.196in) depth

• Mounting Holes: #10-32 on 2in bolt circle

• Through Bore Diameter: 19mm (0.752in)

• Mounting Footprint Narrow Side Width: 50.8mm (2in)

• Mounting Footprint Rounded Side Diameter: 60mm (2.362in)

• Weight: 50g (0.11lb)

ION Servo Face Mount Bracket

The ION Servo Face Mount Bracket (REV-21-2896) allows for easy integration of Servo Motors into the ION System. Mount a servo motor, such as our Smart Robot Servo (REV-41-1097), on a 1/2in pitch and line up perfectly with the MAXPattern on MAXTube.

1in Flat Universal Motor Bracket V2 [Discontinued]

The 1in Flat Universal Motor Bracket V2 (REV-21-1841) changes the holes on the 25mm bolt circle from an M4 to an M3 tight fit hole to accommodate 550 style motors, including the NEO 550 Brushless Motor. To use a BAG Motor, the holes on the 25mm bolt circle need to be drilled out to a M4 tight fit.

Specifications:

• Material: 5052 Aluminum

• Thickness: 3mm (0.12in)

• 0.196in holes on 0.5in grid

• Compatible with the following motors:

  • NEO 1.1, NEO 550, Falcon 500, CIM/Mini CIM, 775Pro/Redline, BAG

• Weight: 46g (0.102lb)

1in Bent Universal Motor Bracket V2 [Discontinued]

The 1in Bent Universal Motor Bracket V2 (REV-21-1842) This bracket is designed to work seamlessly with the most popular motors in FRC. The Bent Universal Motor Bracket V2 changes the holes on the 25mm bolt circle from an M4 to an M3 tight fit hole to accommodate 550 style motors, including the NEO 550 Brushless Motor. To use a BAG Motor, the holes on the 25mm bolt circle need to be drilled out to a M4 tight fit.

#10 Hardware Basics

The REV ION build system uses #10 Hardware to connect, or fasten, brackets and structure together on a robot. Different applications require different length screws. When attaching a bracket to extrusion, shorter screws are generally required. Use longer screws to connect Control System components and other thicker materials.

Hardware Specifications

Button Head Socket Cap Screws

#10 Low Profile Nylon Lock Nut (REV-29-1016)

#10-32 Socket Hex Cap Screws

Shaft End Screw (REV-21-2056)

Standoffs

Aluminum threaded standoffs (Product Family Page) are an easy way to assemble structural components like plates, brackets and tubes. Tapped on each end with a #10-32 thread and a 3/8in flat to flat dimension similar to a #10-32 nut.

Dead Axle Tube - 3/4in

Dead Axle Tube (REV-21-2510) is compatible with the REV ION System and can be used with 3/4in Needle Bearing Carrier (REV-21-2385) and MAXSpline Shaft (REV-21-2520) as the dead axle in a dead axle roller. Can also be used with custom rollers and as structural support.

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

3/4in Dead Axle Tube (REV-21-2510) acts as the structural member in this MAXSpline Shaft (REV-21-2520) dead axle application. Supporting the Dead Axle Tube is a Needle Bearing (REV-21-2386) (3/4in ID, 1in OD) that fits into MAXSpline Shaft. Tube nuts (REV-21-2382-PK10) for the 5/8in ID of the Dead Axle Tube makes mounting your assembly easy. Alternatively you could use a Stepped Bushing (REV-21-2396) to mount your MAXSpline Shaft to your Dead Axle Tube.

Bushing

This Stepped Bushing (REV-21-2396) in conjunction with the MAXSpline Shaft and the 3/4in tube can be used to build robust and effective rollers and intakes for your FRC robot. It can also be used as a pivot point when combined with a MAXTube and 3/4in dead axle.

Endcaps

This MAXSpline Shaft Endcap (REV-21-2393-PK2) enables you to convert MAXSpline Shaft into a live axle driven by a 1/2in Hex shaft.

Ratio Plates

When you need a ratio other than 1:1, Ratio Plates make it easy to position sprockets and pulleys at the perfect center-to-center distance for the given ratio and length of #25 chain or RT25 belt.

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.

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.

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.

Sprockets consist of a disk with straight teeth projecting radially. Sprockets will only work correctly with chain and other sprockets if they are on parallel shafts and the teeth are in the same plane. A chain consists of a continuous set of links that ride on the sprockets to transmit motion. The REV ION Build System is designed around #25 Roller Chain () using compatible #25 Sprockets.

ION Sprockets

Our are compatible with the REV ION system and designed for use with These sprockets are flat and feature a MAXSpline and a 2in bolt circle that patterns outward radially, allow for bolting to structure easily. #25 Hub Sprockets feature a 1/2in hex bore or MAXSpline and transfer torque through a shaft. 1/2in Hex - 16 Tooth - Double sprockets available for chain in tube applications.

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.

NEO Vortex

The is a high-power, high-performance, and high-resolution sensored brushless motor from REV Robotics. It features a dockable controller interface that can be mounted directly to the or a allowing control from any brushless motor controller, like the SPARK MAX. Its through-bore rotor is the heart of its unique interchangeable shaft system, facilitating easy integration with various robot mechanisms.

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

Servo Basics

Servo motors are a specialized kind of motor which can be controlled to move to a specific angle instead of continuously rotating like a DC motor. Instead of a hex output shaft like the DC motor, servos have an output spline. A spline is a specific groove pattern cut into the shaft which allows the rotation of the servo motor to be transmitted to the attached Aluminum Servo Horn or . Splines are like keys, so only matched types will fit together. The REV Robotics Servos all use a 25T spline pattern. If the gears or spline of the REV Robotics Smart Robot Servo () become damaged, they are replaceable using a Replacement Gear Set ().

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.

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

REV Robotics offers three types of ION wheels: , and . There are two types of ION Traction wheels available: the standard and the . The main focus of the traction wheels is to pull a robot (or create traction) in a forward/backwards motion.

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

This custom-designed #25 Chain Tool () also commonly referred to as a "chain break" or "chain breaker", allows teams to easily break and re-assemble #25 Chain (). The mandrel is used to push out the chain pin. If using Master Links (), the pin can be completely removed, but the depth guide screw allows the option of partially pressing out the pin and then re-assembling without master links.

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