Mecanum wheels provide easy and efficient omni-directional motion for robots.

Description
Specifications
Documentation

The 4 in. HD Mecanum wheel comes fully assembled and ready to go and comes in three different bore sizes.

A full set consists of 2 "right" wheels and 2 "left" wheels. The "right" and "left" refer to the direction the rollers are pointing when viewing the wheel as if your about to get run over by the wheel itself. If the roller in the middle of the wheel points up and to the right, it's a "right" wheel, and up and to the left would be a "left" wheel.

The configuration of these "right" and "left" wheels is important to a mecanum drive system! Be aware that the "right" wheel should not mean that it goes on the right side of your robot. The proper configuration would be to have the wheels create an "X" pattern when viewing your robot from above and drawing lines parallel to the rollers as viewed.
This means that a "right" wheel would be the FRONT RIGHT, and the REAR LEFT position, while the "left" wheel would be in the FRONT LEFT, and REAR RIGHT, of your robot when viewed from above. All 4 wheels are required to make a Mecanum drive holonomic system to work properly.
Using these for an intake? This has been a great use of these wheels as well! The angle of these wheels help drive the object in one direction, so you can pull in the object at the same time as pushing at an angle from the intake.
This version of the wheel can handle a 200 pound load per wheel for a total 800 pound load if using as drive wheels! The interior body of this wheel is made of molded black polycarbonate, 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.
Wheel Bores:
- Bearing Bore
  - the Original 4 in. HD Mecanum wheel
  - Use with a 1/2 in. hex hub for Heavy Duty and hex applications
- Nub Bore
  - Perfect for FTC robots
- 1/2 in. Hex
  - Bore molded directly into polycarbonate center body
  - While still being able to handle 200lbs of load, BE AWARE: these have a limited torque capacity. Recommended use in light duty applications (FTC robots or non-drive train FRC items such as an intake)
- 3/8 in. Hex
  - Bore molded directly into polycarbonate center body
  - While still being able to handle 200lbs of load, BE AWARE: these have a limited torque capacity. Recommended use in light duty applications (FTC robots or non-drive train FRC items such as an intake)
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 or Right wheels. They are sold without hubs, sprockets, or bearings.

Included Items:
Individual Hardware within Each Wheel:
- 2 - HD Mecanum Plates
- 2 - Hubs
- 9 - Individual 4 in. Wheel Rollers
- 9 - Brass Axle Tubes
- 9 - M3 x 55 mm SHCS
- 9 - M3 x 0.5 in Nylock Nut
- 18 - 0.125 in diameter Rivets
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Usage:
Nub Bore Wheels
For FTC Robots: If attached to a shaft or NeveRest motor, these parts are needed for each wheel.
- Attach an AndyMark Nub or Tetrix Motor Hub directly to the Nub Bore version of this wheel.
  - Four 2in long 6-32 screws such as am-1499 are required per wheel for this method.
Bearing Bore Wheels
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.
- #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.
- 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).
Hex Bore
Direct Drive:
- Simple! with a hex shaft
Learn how to position these wheels by watching this video.
- Body Material, Inner: Molded black polycarbonate
- Body Material, Outer: 0.12 in. thick steel, zinc plated
- Bolt Pattern: 6 holes (0.2 in. diameter) on a 1.875 in. diameter circle
- Bore: Bearing Bore, Nub Bore, 1/2 in. Hex, 3/8 in. Hex
- Diameter: 4 in. [100 mm]
- Forward / Reverse Coefficient of Friction: 0.7 (on tight pile carpet)
- Load Capacity: 200 lbs. per wheel
- Number of Rollers: 9
- Roller Axle: Brass Tube
- Roller Bearing Material: Nylon spinning over brass tube
- Roller Durometer: 80A
- Roller Material, Inside: Nylon (white)
- Roller Material, Outside: TPU
- Sideways Coefficient of Friction: 0.6 (on tight pile carpet)
- Weight: 0.9 lbs. per wheel
- Width Across Middle: 2.18 in.

Wheel Bores:

Roller and Axle Design:

Wheel Structure:

Included Items:

Usage: