Compliant wheels are not intended for moving robots, but moving objects. Compliant wheels give way to allow rigid objects to be manipulated easily. A line of multiple wheels on a driven hex axle creates a very effective roller that ignores variations in the objects being driven. This makes for high-performance intakes and internal conveyors.

Different durometer ratings give each wheel unique characteristics. Green wheels (35A durometer) are the softest and most compliant around objects, while orange (40A), maroon (45A), blue (50A), and black (60A) wheels are increasingly firm. The increased firmness also allows the latter wheels to carry a higher RPM rating. Check out the downloads tab for a chart showing wheels and their maximum RPM. 

Please note maroon wheels are only intended for use in FTC. If more powerful motors are used to drive it the spokes may fail.

Specifications

• Bore: 1/2 in. Hex, 3/8 in. Hex, Nub Bore, 5 mm Hex
• Diameter: 4 in.
• Durometer: 35A (Green), ⠀40A (Orange), ⠀45A (Maroon), ⠀50A (Blue), ⠀60A (Black), ⠀80A (Gray)
• Hole Pattern: Qty 4 3.5 mm Holes on a 16 mm Circle for 8 mm bore wheels
• Material: TPU, ⠀Polycarbonate
• Maximum RPM: 3000-9000
• Weight: 0.228 - 0.269 Lbs
• Width: 1 in.

Documents

Layout Print(s)

am-3562 4IN 375Hex Compliant Wheel REV3.PDF

am-3563 4IN 8mm Compliant Wheel REV4.PDF

am-3480 4IN 500Hex Compliant Wheel REV3.PDF

am-4538 4IN 5mm Hex Compliant Wheel.PDF

CAD File(s)

am-3562 4IN 375Hex Bore Compliant Wheel REV2.STEP

am-3563 4IN 8mm Round Compliant Wheel REV2.STEP

am-3480 4IN 500Hex Bore Compliant Wheel REV2.STEP

am-4538 4IN 5mm Hex Compliant Wheel.STEP

Guide(s)

4 inch Compliant Wheel Expansion.pdf

• Material Durometer: 60A
• Diameter: 4"
• Width: 1"
• Bore: 0.314" (8mm)
• Maximum RPM: 9000 RPM
• Weight: 0.268 Lbs

These rollers are used in the 4" DuraOmni Wheel. Eight of these roller are used to allow the wheel to roll smoothly and omni-directionally.

Eight replacement rollers are included in this set. No other hardware is included.

Specifications:

• Number of Rollers: 8
• Roller Material, Outside: Gray TPU rubber
• Roller Durometer: 80A
• Roller Material, Inside: white nylon
• Roller Bearing Material: nylon spinning on steel (dowel axle not included)
• Roller Length: 1.62 inches
• Roller Diameter: 0.9 inch
• Roller Weight: 0.032 pounds each.

This heavy duty omni wheel is a vast improvement over our older 4" omni wheels and other wheels on the market. The body has been totally redesigned with durability and mobility in mind. The design intent is to provide a smooth roll along with the ability to handle impacts very well.

The body is made from black polycarbonate, while the rollers are each molded with a nylon core and TPU tread. These rollers spin smoothly on a captured 1/8" x 1.875" dowel pin.

This image shows how to attach the DuraOmni to the AM14U2

Specifications: 

• Diameter: 4"
• Width Across Middle: 2.0 inches
• Bore: 1.125 inch diameter x 0.36" deep with a 0.96" diameter thru hole
• Bolt Pattern: 6 holes (0.157 in.) on a 1.875 inch bolt circle
• Body Material: Black polycarbonate
• Load Capacity: 120 pounds (rollers don't spin past this point)
• Weight: 0.59 pounds
• Number of Rollers: 8
• Roller Material, Outside: Gray TPU rubber
• Roller Durometer: 77A
• Roller Material, Inside: white nylon
• Roller Bearing Material: nylon spinning on steel
• Roller Axle: 1/8" diameter steel dowel pin
• Roller Length: 1.62 inches
• Roller Diameter: 0.9 inch
• Assembled and Repairable by installing or removing 10-24 screws

Included Hardware:

• One - Interior polycarbonate body piece
• Two - Outer polycarbonate body pieces
• Eight - Gray Rollers
• Eight - 1.875x1/8 Steel Dowel Pins
• Eight - #10-24 x 0.50" Hex Head Screws, thread-forming

Usage: 
With Axle and Hub:

• To drive this wheel with an axle and hub, pick any of the AndyMark hubs to this wheel. Hubs are NOT included in the price of the wheel. No bearings are needed when driving with an axle.

With Sprocket:

• To drive this wheel with a sprocket, the sprocket needs to be attached to the side of the wheel with screws, and two ball bearings are to be pressed into the wheel, one on each side.

With Bearings, as a Caster:

• Bearings can be pressed in to the 1-1/8" diameter pockets on each side of the wheel. This setup creates a nice caster.

4" DuraOmni Wheel with 1/2" id bearings. This new heavy duty omni wheel is a vast improvement over our older 4" omni wheels and other wheels on the market. The body has been totally redesigned with durability and mobility in mind. The design intent is to provide a smooth roll along with the ability to handle impacts very well. 

The body is made from black polycarbonate, while the rollers are each molded with a nylon core and TPU tread. These rollers spin smoothly on a captured 1/8" x 1.875" dowel pin. 

Specifications: 

• Diameter: 4 inches
• Width Across Middle: 2.0 inches
• Bore: 0.500 inch
• Bolt Pattern: 6 holes (0.157 in.) on a 1.875 inch bolt circle
• Body Material: Black polycarbonate
• Load Capacity: 120 pounds (rollers don't spin past this point)
• Weight: 0.72 pounds
• Number of Rollers: 8
• Roller Material, Outside: Gray TPU rubber
• Roller Durometer: 77A
• Roller Material, Inside: white nylon
• Roller Bearing Material: nylon spinning on steel
• Roller Axle: 1/8" diameter steel dowel pin
• Roller Length: 1.62 inches
• Roller Diameter: 0.9 inch
• Assembled and Repairable by installing or removing 10-24 screws
• Half inch id bearings pre-pressed into hub

Individual Components within this Part:

• One - Interior polycarbonate body piece
• Two - Outer polycarbonate body pieces
• Eight - Gray Rollers
• Eight - 1.875x1/8 Steel Dowel Pins
• Eight - #10-24 x 0.50" Hex Head Screws, thread-forming
• Two - 1/2" id Bearing, Shielded (R8ZZ) (am-0181)

Usage:
With Axle and Hub:

• If you wish to drive one of these wheels with an axle and hub, then no bearings are needed. Use am-3047 instead.

With Sprocket:

• To drive this wheel with a sprocket, the sprocket needs to be attached to the side of the wheel with screws. This setup will work nicely spinning over a 1/2" diameter axle.

This is our 4" aluminum omni wheel. This wheel features the 8mm center bore with 4-hole pattern used in multiple building systems used in FIRST Tech Challenge.

Specifications: 

• Diameter: 3.96 inches
• Width Across Middle: 0.375 inches
• Bore: 0.315"
• Bolt Pattern: Four 0.157" holes on a 0.630" circle.
• Body Material: Aluminum
• Load Capacity: 50 pounds (rollers do not spin past this weight)
• Weight: 0.412 pounds
• Number of Rollers: 9
• Roller Material: Black SBR rubber
• Roller Bearing Material: Brass
• Roller Axle: Steel dowel pin
• Roller Diameter: 3/4 inch
• Roller Durometer: 80A
• Repairable by removing perimeter #10 screws

Included Hardware:

• One - 4" Aluminum Omni Inner Plates
• Two - 4" Aluminum Omni Outer 8mm Hub Plate
• Nine - Black SBR Rollers
• Nine - 1x1/8 Steel Dowel Pins
• Eighteen - Omni-roller Sleeves
• Six - Individual #10-32 x 3/8" Button Head Phillips Screws
• Six - #10-32 Pem Nuts
• One - FTC Wheel Conversion Plate
• Six - Individual #10-32 x 5/8" SHCS

4 inch, HEAVY DUTY Mecanum wheel set, these come assembled as shown in the picture. This is a set of 4 wheels, consisting of 2 "right" wheels and 2 "left" wheels. All 4 wheels are required to make a Mecanum drive holonomic system to work properly. This version of the wheel can handle a 200 pound load per wheel. The interior body of this wheel is made of molded black poycarbonate, while the perimeter side plate is made of 1/8 inch thick steel, zinc plated. The perimeter plate is riveted to the interior body, and each perimeter bent tab rests on the interior body rim. This support allows for the wheel to handle more load. 

Specifications:

• Diameter: 4 in.
• Width Across Middle: 2.18 in.
• Bore: 1.124 in.
• Bolt Pattern: 6 holes (0.2 in. diameter) on a 1.875 in. diameter circle
• Body Material, Outer: 0.12 in. thick steel, zinc plated
• Body Material, Inner: molded black polycarbonate
• Load Capacity: 200 pounds per wheel
• Forward / Reverse Coefficient of Friction: 0.7 (on tight pile carpet)
• Sideways Coefficient of Friction: 0.6 (on tight pile carpet)
• Weight: 0.9 pound (each wheel)
• Number of Rollers: 9
• Roller Material, Outside: Urethane rubber (gray)
• Roller Material, Inside: Nylon (white)
• Roller Durometer: 80A
• Roller Bearing Material: Nylon spinning over brass tube
• Roller Axle: Brass tube

Individual Hardware within Each Wheel:

• Two - HD Mecanum Plates
• Two - Hubs
• Nine - Individual 4 in. Wheel Rollers
• Nine - Brass axle tubes
• Nine - M3 x 55MM SHCS
• Nine - M3 x 0.5" Nyock Nut
• Eighteen - 1/8 in. dia. rivets

Roller and Axle Design:
The gray urethane rubber roller (am-3027) has a durometer rating of 80A. The roller has a Nylon core, and rides on a stationary brass tube. 

Wheel Structure:
9 rubber rollers are sandwiched between 2 steel plates. The steel plates are riveted to two interior polycarbonate hubs, which form the interior of the wheel. The two interior pieces are held together by the fastening technique of the rollers being attached. 

These wheels can be purchased individually as Left (am-3026L) or Right (am-3026R) wheels. They are sold without hubs, sprockets, or bearings. 

Usage: 

For FTC Robots: If attached to a shaft or NeveRest motor, these parts are needed for each wheel

• A wheel conversion plate can be used to allow for mounting to smaller shaft sizes
• #10-24 thread-forming screws are used to fasten the conversion plate to the wheel (6 per wheel).
• 6mm D Bore AndyMark Nub or other 6mm Hub are needed to attach each wheel to a 6mm axle or NeveRest motor shaft.
•  

With Axle and Hub: If driven by a shaft, these parts are needed for each wheel

• A hub that matches the size of the drive shaft. For 1/2 in. dia. shafts, use a 1/2 in. Key Hub (am-0077a) for each wheel.
• #10-24 thread-forming screws are used to fasten a hub to the wheel (we suggest 6).
• 1/8 x 1/8 x 3/4 steel machine key (am-1043) is needed, one per wheel

With Sprocket: If driven by a sprocket, these parts are needed for each wheel

• Flanged ball bearings (qty. 2) with 1.125 in. od: either 3/8 in. inside diameter (am-0209), or 1/2 in. i.d. (am-0181)
• A sprocket (type A) with a bolt hole circle of 1.875 in. diameter mounts to the wheels' interior bolt pattern.
• #10-24 thread-forming screws are used to fasten a hub to the wheel (we suggest 6).

FTC Note: This product is NOT legal for FTC, we recommend our Stealth Wheel.

Product Overview: 
This is a 4 inch diameter wheel with HiGrip tread. The design of this wheel is very similar to our popular 6" HiGrip wheel, but with a smaller, 4" diameter. We feel that these wheels are a more durable option for teams' drivetrains. While they provide good traction, they make for a maintenance-free wheel for the average team. Under normal circumstances we feel that these wheels will last most FIRST Robotics Competition teams the entire season. No bearings or hubs are included in this wheel. 

Specifications:

• Diameter: 4 inches
• Body Material: Polycarbonate, black
• Tread Material: TPU (thermoplastic polyurethane)
• Bore: 0.95 inch
• Width: 1.375 inch
• Weight: 0.31 pound
• Bolt Pattern: six holes (0.17 inch diameter) on a 1.875 inch diameter bolt circle
• Static coefficient of friction on tight pile carpet: 1.07
• Static coefficient of friction on HDPE: 0.31
• Load capacity: 100 pounds

Usage: 

• Use #10-24x3/4 thread forming screws to attach sprockets or hubs to this wheel. Many thread locking materials are not compatible with polycarbonate and can eat away at the plastic. Be sure to check which adhesives are okay to use with this product. This link will allow you to check which materials are okay to use with what adhesives, http://bit.ly/loctitematerialcheck

With Axle and Hub:

• If you wish to drive this wheel with an Axle and Hub, you can pick your hub by fitting any of the AndyMark hubs (not included) to this wheel. If this is your choice, then no bearing is needed. Use #10-24x3/4 thread forming screws to fasten a hub to this wheel.

With Sprocket:

• If you wish to drive this wheel with a sprocket, then the sprocket needs to be attached to the side of the wheel, and two ball bearingsneed to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209. Use #10-24x3/4 thread forming screws to fasten the sprocket to the wheel.

With Bearings:

• To press bearings into this wheel (for a free spinning wheel or for use with a sprocket), two ball bearings need to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209.

HiGrip wheels provide superior traction for robot movement. HiGrip wheels feature an aggressive tread pattern providing maximum transfer of gearbox power to the ground. A robust polycarbonate core means these wheels are up to the challenge for high impact and speed applications. Varying durometers mean you can choose just how grippy these wheels can be. White or 77A durometer HiGrip wheels have a long life and provide good traction. Black or 60A durometer HiGrip wheels have an intermediate life and higher grip than white. Blue or 60A durometer HiGrip wheels provide the most traction and will wear quickly as a result. The bolt pattern and bore of these wheels allow for convenient bearing placement and easy attachment to other motion parts such as sprockets and pulleys. 

Product Usage: 
Many thread locking materials are not compatible with polycarbonate and can eat away at the plastic. Be sure to check which adhesives are okay to use with this product. This link will allow you to check which materials are okay to use with what adhesives, http://bit.ly/loctitematerialcheck

Specifications:

• Diameter: 4" or 6"
• Body Material: Polycarbonate
• Tread Material: Thermoplastic Polyurethane
• Durometer: 77A (Grey), 60A (Black), 50A (Blue)
• Bore: 0.95", with bearing pockets of 1.124" diameter x 0.25" deep on both sides
• Bolt Circle: Six holes (0.17" diameter) on a 1.875" diameter bolt circle
• 77A Carpet CoF: 0.95-1.0 Static
• 60A Carpet CoF: 0.77 Static
• 50A Carpet CoF: 0.97 Static
• 4" Wheel Load Capacity: 100 Pounds
• 6" Wheel Load Capacity: 90 Pounds

Usage: 
Use #10-24x3/4 thread forming screws to attach sprockets or hubs to this wheel. Many thread locking materials are not compatible with polycarbonate and can eat away at the plastic. Be sure to check which adhesives are okay to use with this product. This link will allow you to check which materials are okay to use with what adhesives, http://bit.ly/loctitematerialcheck

With Axle and Hub:

• If you wish to drive this wheel with an Axle and Hub, you can pick your hub by fitting any of the AndyMark hubs (not included) to this wheel. If this is your choice, then no bearing is needed. Use #10-24x3/4 thread forming screws to fasten a hub to this wheel.

With Sprocket:

• If you wish to drive this wheel with a sprocket, then the sprocket needs to be attached to the side of the wheel, and two ball bearings need to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209. Use #10-24x3/4 thread forming screws to fasten the sprocket to the wheel.

With Bearings:

• To press bearings into this wheel (for a free spinning wheel or for use with a sprocket), two ball bearings need to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209.

HiGrip wheels provide superior traction for robot movement. HiGrip wheels feature an aggressive tread pattern providing maximum transfer of gearbox power to the ground. A robust polycarbonate core means these wheels are up to the challenge for high impact and speed applications. Varying durometers mean you can choose just how grippy these wheels can be. White or 77A durometer HiGrip wheels have a long life and provide good traction. Black or 60A durometer HiGrip wheels have an intermediate life and higher grip than white. Blue or 60A durometer HiGrip wheels provide the most traction and will wear quickly as a result. The bolt pattern and bore of these wheels allow for convenient bearing placement and easy attachment to other motion parts such as sprockets and pulleys. 

Product Usage: 
Many thread locking materials are not compatible with polycarbonate and can eat away at the plastic. Be sure to check which adhesives are okay to use with this product. This link will allow you to check which materials are okay to use with what adhesives, http://bit.ly/loctitematerialcheck

Specifications:

• Diameter: 4" or 6"
• Body Material: Polycarbonate
• Tread Material: Thermoplastic Polyurethane
• Durometer: 77A (Grey), 60A (Black), 50A (Blue)
• Bore: 0.95", with bearing pockets of 1.124" diameter x 0.25" deep on both sides
• Bolt Circle: Six holes (0.17" diameter) on a 1.875" diameter bolt circle
• 77A Carpet CoF: 0.95-1.0 Static
• 60A Carpet CoF: 0.77 Static
• 50A Carpet CoF: 0.97 Static
• 4" Wheel Load Capacity: 100 Pounds
• 6" Wheel Load Capacity: 90 Pounds

Usage: 
Use #10-24x3/4 thread forming screws to attach sprockets or hubs to this wheel. Many thread locking materials are not compatible with polycarbonate and can eat away at the plastic. Be sure to check which adhesives are okay to use with this product. This link will allow you to check which materials are okay to use with what adhesives, http://bit.ly/loctitematerialcheck

With Axle and Hub:

• If you wish to drive this wheel with an Axle and Hub, you can pick your hub by fitting any of the AndyMark hubs (not included) to this wheel. If this is your choice, then no bearing is needed. Use #10-24x3/4 thread forming screws to fasten a hub to this wheel.

With Sprocket:

• If you wish to drive this wheel with a sprocket, then the sprocket needs to be attached to the side of the wheel, and two ball bearings need to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209. Use #10-24x3/4 thread forming screws to fasten the sprocket to the wheel.

With Bearings:

• To press bearings into this wheel (for a free spinning wheel or for use with a sprocket), two ball bearings need to be pressed into the wheel (one on each side). The ball bearing must have a 1.125" od. For a 1/2" id, use am-0181 or am-0029. For a 3/8" id, use am-0209.

The 4 in. Performance Wheel is a virtually indestructible wheel made out of solid 6061 aluminum. This competition-proven design has been used on FIRST Robotics Competition robots for many years. This new iteration of the wheel has been designed to keep costs down, as it is made from a custom extrusion instead of being fully machined from billet. This wheel can take anything an FRC robot can throw at it, and much more. Additionally this new version also includes a 1/8 in. thick boss on the rear (flat) side of the wheel to prevent unwanted friction in bearing outer races. This also reduces the part count on drivetrains.

This wheel is designed to be driven by a 1/2 in. Hex shaft, but also allows for other motion hardware that utilizes a 1.875 in 6-hole bolt circle found in many AndyMark and competition robotics products. To mount one of these to the rear (flat) side, use a 250 Sprocket and Pulley Spacer. To mount one to the front, use a 550 Sprocket Spacer. This wheel does not include tread material, which is available separately to tailor this wheel's performance to your application.

Note: This wheel is designed to utilize rivets to attach the tread to the wheel. AndyMark recommends steel 1/8" diameter rivets with a 0.251" - 0.312" grip range. The wheel has been manufactured with no holes on the rim, as it is intended to be a blank canvas for teams to install rivets freely. An installation video is coming soon.

Specifications:

• Material: 6061 Aluminum
• Weight: 0.35 lbs
• Diameter: 4 in. (with tread)
• Tread Width: 1 in.
• Bore: 1/2" hex
• Hub Mounting Holes: 6 threaded holes for #10-32 screws on a 1.875 in. diameter bolt circle

The 4 in. Performance Wheel is a virtually indestructible wheel made out of solid 6061 aluminum. This competition-proven design has been used on FIRST Robotics Competition robots for many years. This new iteration of the wheel has been designed to keep costs down, as it is made from a custom extrusion instead of being fully machined from billet. This wheel can take anything an FRC robot can throw at it, and much more. 

This wheel is designed to be supported by 1.125 in. OD (FR8) flanged bearings, but also allows for other motion hardware that utilizes a 1.875 in. 6-hole bolt circle found in many AndyMark and competition robotics products. To mount one of these to the rear (flat) side, use a 250 Sprocket and Pulley Spacer. To mount one to the front, use a 550 Sprocket Spacer. This wheel does not include tread material, which is available separately to tailor this wheel's performance to your application. 

Note: This wheel is designed to utilize rivets to attach the tread to the wheel. AndyMark recommends steel 1/8" diameter rivets with a 0.251" - 0.312" grip range. The wheel has been manufactured with no holes on the rim, as it is intended to be a blank canvas for teams to install rivets freely. 

Specifications:

• Material: 6061 Aluminum
• Weight: 0.30 lbs
• Diameter: 4 in. (with tread)
• Tread Width: 1 inch
• Bore: Press for 1.125 in OD (FR8) Flanged Bearing
• Hub Mounting Holes: 6 threaded holes for #10-32 screws on a 1.875" diameter bolt circle

The 4" Performance Wheel is a virtually indestructible wheel made out of solid 6061 aluminum. This competition-proven design has been used on FIRST Robotics Competition robots for many years, and is now available in a version friendly to FIRST Tech Challenge robots. This new iteration of the wheel has been designed to keep costs down, as it is made from a custom extrusion instead of being fully machined from billet in past versions of this wheel. This wheel can take anything an FRC or FTC robot can throw at it, and much more. 

This wheel is designed to be driven by an AndyMark Nub and a 6mm D shaft, but also allows for other motion hardware that utilizes a 1.875" 6-hole bolt circle found in many AndyMark and competition robotics products. To mount one of these to the rear (flat) side, use a 250 Sprocket and Pulley Spacer. To mount one to the front, use a 550 Sprocket Spacer. This wheel does not include tread material, which is available separately to tailor this wheel's performance to your application.

Note: This wheel is designed to utilize a zip-tie to attach and tension the tread to the wheel. While the method is similar to the previous version of this wheel (am-3434) a new guide on how to attach tread to this wheel is coming soon.

Specifications:

• Material: 6061 Aluminum
• Weight: 0.35 lbs
• Diameter: 4 in. (with tread)
• Tread Width: 1 in.
• Bore: 8mm
• Hub Mounting Holes: 4X #6-32 clearance on 16mm bolt circle, 6 threaded holes for #10-32 screws on a 1.875" diameter bolt circle

Plaction wheels are a lightweight wheel made of strong molded polycarbonate. This four inch diameter wheel has high traction blue nitrile roughtop tread. High performance plastic and high traction, Plaction.

Specifications: 

• Diameter: 4 inches
• Width: 1.00 inch
• Width at Hub: 1.64 inches
• Bore: 1.124 inch bore, 0.25 inches deep on either side
• Bolt Pattern: 6 Holes around a 1.875" diameter circle
• Body Material: Black Polycarbonate
• Load Capacity: 200 pounds (estimated)
• Weight: 0.55 pounds
• Tread Capture: 0.9 inch wide (clamps tread)
• Tread Width: 1 inch
• Tread Type: Roughtop Conveyor Belting, Nitrile Material
• Coefficient of Friction on tight-pile carpet:

Included Hardware:

• Two - 4" Plaction Wheel Halves
• Six - Individual #10-32 x 1.5" SHCS (am-1014)
• Six - Individual #10-32 Nylock Nuts
• One - 4" Wheel Roughtop Tread
• Two - Individual Alligator Clips
• One- Individual Alligator Clip Pins

Usage: 

There are two ways to drive this wheel. One way is with a Axle and Hub, and the other is with a Sprocket. To install a sprocket or hub onto a Plaction wheel, use 10-32 x 1.75" socket head screw (qty. 3 or 6), and 10-32 nylock nuts. To use one sprocket on each side of a Plaction wheel (2 sprockets total) use 10-32 x 2.5" screws(3 or 6) and 10-32 nylock nuts. 

With Axle and Hub:

• If you wish to drive this wheel with an Axle and Hub, you can pick your hub by fitting any of the AndyMark hubs (except the Small DD Globe Hub) to this wheel. Hubs are NOT included in the price of the wheel. If this is your choice, then no bearing is needed.

With Sprocket:

• If you wish to drive this wheel with a sprocket, then the sprocket needs to be attached to the side of the wheel, and two ball bearings need to be pressed into the wheel (one on each side). The smallest sprocket that will work with these wheels is a S35-24 tooth and a S25-36 tooth sprocket. 

With Bearing:

If your design needs this wheel to spin on a stationary axle (and possibly be driven by a sprocket), you will need 2 bearings with a 1.125" od pressed into this wheel. Use am-0029 for a 1/2" bore and am-0209 for a 3/8" bore. One bearing is pressed into each side of the wheel. Bearings are NOT included in the price of this wheel.

With Tread:

This wheel is designed to capture 1" wide conveyor belt tread (Roughtop or Wedgetop) between 2 wheel halves. The 6 perimeter screws can be loosened by 1/8 inch to install the desired tread. We recommend using Alligator Clips to hold the tread together on the wheel. One 4" wheel Roughtop Tread is included in the price of the wheel.

For a Wider Wheel: 

This wheel is designed so that a 3" PVC schedule 40 pipe can be inserted between the two wheel halves, and a wider wheel can be created (additional tread may be needed).

This is the rubber roller and spindle used in the 4" Mecanum Wheels. 

Specifications:

• Material (roller): TPU polyurethane
• Material (axle): Nylon
• Weight: 0.04 pounds

Included Hardware:

• Two - Individual 4-40 x 1/2" PPHS
• Two - Individual Rollers
• Two - Individual Washers
• One - Wheel Spindle

This is a single AndyMark Mecanum-style wheel, 4" in diameter, sold in an unassembled kit. The left and right-handed wheels use the same parts, and simply need to be assembled in different fashions in order to be made into the correct left and right wheels. This wheel is perfect for your FTC robot. If you're looking for an FRC drive train mecanum solution in a 4" form factor, check out the 4" HD Mecanum Left (am-3026L) and Right (am-3026R) Wheels.

A set of four wheels is available as a kit found here, am-2626(Wheel Set).
Replacement rollers can be found here: 4" Standard Mecanum Roller Kit, Single Axle (am-2539)


Specifications:

• Diameter: 4 inch (100mm)
• Width across middle: 1.125 inch (28.6 mm)
• Width at rollers: 2.0 inch (50 mm)
• Bore: 0.315 inch (8 mm)
• Bolt Pattern - Inner: 0.138 inch (3.5 mm) diameter holes on 0.630 inch (16 mm) bolt circle
• Bolt Pattern - outer: 0.200 inch (5.1 mm) diameter holes on 1.875 inch (47.6 mm) bolt circle
• Body Material: 50/50 ABS & PC
• Load Capacity: 17 pounds (7.7 kg) per wheel or 50 pounds (31.6 kg) per set of 4
• Forward / reverse coefficient of friction: 0.51 on FTC Soft-tile
• Sideways coefficient of friction: 0.67 on FTC Soft-tile
• Weight: 0.35 pounds per wheel (0.16 kg)
• Number of rollers: 6, with each being 2 independent rollers
• Roller material, outside: TPU polyurethane
• Roller durometer: 80A
• Roller axle material: Nylon

Included Hardware:

• Two - Mecanum Body Halves
• Twelve - Individual 4-40 x 1/2" PPHS
• Twelve - Individual Rollers
• Twelve - Individual Washers
• Six - Wheel Spindle
• Six - Individual 4-40 x 1" STS

Usage:
This wheel is designed to directly mount to a Tetrix Wheel Hub.

To use with Axle and Hub:

• If you wish to drive this wheel with an Axle and Hub, you can pick your hub by fitting any of the AndyMark hubs (except the Small DD Globe Hub) to this wheel. Hubs are NOT included in the price of the wheel. If this is your choice, then no bearing is needed.