edit

# 4WD Mecanum Wheel Robot Kit Series

4WD Mecanum Wheel Robot Kit series products are 4 wheel drive mobile platforms based on Mecanum wheels. Each kit contains two left mecanum wheels as well as two right mecanum wheels. The four Mecanum wheels are each connected to a separate motor with independent control. Depending on each individual wheel direction and speed, the mobile platform can move forward, backward, sideways and any other desired directions or spin. Two remote control modules – BLE module and RF module – can be added on this kit to allow remote control.

The Mecanum wheel is one design for a wheel which can move a vehicle in any direction. It is a conventional wheel with a series of rollers attached to its circumference. These rollers each have an axis of rotation at 45° to the plane of the wheel and at 45° to a line through the centre of the roller parallel to the axis of rotation of the wheel. There are two types of Mecunum wheels, left-handed and right-handed Mecunum wheel; the difference between them is the orientation of rollers. For left-handed Mecunum wheel, as shown below, rollers are orientated from lower right to upper left. Rollers for right-handed wheels are installed in the opposite way.

The installation of the 4WD Mecanum Wheel kit should demand some carefulness. A correct configuration requires each of four wheels is set in the way as shown below, where the rotation axis of each wheel’s top roller points to the center of the platform. Please notice that all the dynamic analysis and prewritten codes are based on this configuration.

The angled peripheral rollers translate a portion of the force in the rotational direction of the wheel to a force normal to the wheel direction. Depending on each individual wheel direction and speed, the resulting combination of all these forces produce a total force vector in any desired direction. Let the radius of the wheel to be R, the angular velocity of four wheels to be ω1, ω2, ω3, ω4, the speeds of rollers on each wheel to be _ν_g1, _ν_g2, _ν_g3 and _ν_g4, and the speed of platform in x-direction, y direction and angular velocity to be _ν_x, _ν_y, and ω0. The global coordinate origins at О, the center of the platform, and local coordinate systems at each wheel have origin of O1, O2, O3 and O4. The distance from the mid of platform to the mid of wheel is L1, and L2 is for the distance between mid of the platform to the wheel’s axis of rolling. α is the angle of the rollers: 45º in this case.

In the global coordinate, the speed at the center of wheel 1, O1, is

While in the local coordinate at wheel 1, the speed of O1 is

Combine equation (1) ~ (4), we have

Solving (5) and (6), then the angular velocity of wheel 1 is

Similarly, the velocity of other 3 wheels can be calculated as

The equation (8) shows the relationship between the rotation speeds of the wheels and the movement of the platform. Theoretically, the platform can move in any direction by a proper combination of the four wheels'angular velocity. In fact, For this platform, The most common used movements are quite limited. Here we give out a simplified working principle of the platform. If you are disgusted with the numbers or equations, just ignore the dynamic analysis section, and read the figure below.

Moving all four wheels in the same direction causes forward or backward movement, running the wheels on one side in the opposite direction to those on the other side causes rotation of the vehicle, and running the wheels on one diagonal in the opposite direction to those on the other diagonal causes sideways movement.

## Features¶

• Mecanum Wheel Inside

• Omni-directional Mobility

• Flexibility & Extendibility

• RF/BLE Control Choices

## Part List¶

1. Left Mecanum Wheel Kit

`
Parts Name Specification Material Quantity
1 Left Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 1 pcs
2 DC Motor 25GA 370 Metal 1 pcs
3 Motor Support for DC Motor 25 Series Metal 1 pcs
4 Shaft Connector Ф13.9mm*23mm/6mm Aluminum 1 pcs
5 Set Screw M3×5 Metal 2 pcs
6 Screw, Spring Lock Washer and Plain Washer assemblies M4×18 Metal 1 pcs
7 Cross Recessed Pan Head Screw M3×8 Metal 2 pcs
8 Cross Recessed Pan Head Screw with Washer M3×8 Metal 4 pcs
9 Hexagon Nut M3 Metal 4 pcs
1. Right Mecanum Wheel Kit

Parts Name Specification Material Quantity
1 Right Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 1 pcs
2 DC Motor 25GA 370 Metal 1 pcs
3 Motor Support for DC Motor 25 Series Metal 1 pcs
4 Shaft Connector Ф13.9mm*23mm/6mm Aluminum 1 pcs
5 Set Screw M3×5 Metal 2 pcs
6 Screw, Spring Lock Washer and Plain Washer assemblies M4×18 Metal 1 pcs
7 Cross Recessed Pan Head Screw M3×8 Metal 2 pcs
8 Cross Recessed Pan Head Screw with Washer M3×8 Metal 4 pcs
9 Hexagon Nut M3 Metal 4 pcs
1. Basic Version

Parts Name Specification Material Quantity
1 Chassis 250*145*5mm, Black PMMA 1 pcs
2 Upper Deck 192*145*5mm, Black PMMA 1 pcs
3 Battery Cover 68*47*2mm, Black PMMA 1 pcs
4 Left Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
5 Right Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
6 DC Motor 25GA 370 Metal 4 pcs
7 Motor Support for DC Motor 25 Series Metal 4 pcs
8 Shaft Connector Ф13.9mm*23mm/6mm Aluminum 4 pcs
9 Set Screw M3×5 Metal 8 pcs
10 Screw, Spring Lock Washer and Plain Washer assemblies M4×18 Metal 4 pcs
11 Screw, Spring Lock Washer and Plain Washer assemblies M2×8 Metal 20 pcs
12 Cross Recessed Pan Head Screw M3×8 Metal 26 pcs
13 Cross Recessed Pan Head Screw with Washer M3×8 Metal 16 pcs
14 Hexagon Nut M3 Metal 16 pcs
15 Hexagon Distance Holder M3×40 Metal 5 pcs
16 Hexagon Distance Holder M3×10 Metal 4 pcs
17 Hexagon Distance Holder M2×15 Metal 4 pcs
18 Hexagon Distance Holder M2×10 Metal 6 pcs
1. RF Version

Parts Name Specification Material Quantity
1 Chassis 250*145*5mm, Black PMMA 1 pcs
2 Upper Deck 192*145*5mm, Black PMMA 1 pcs
3 Battery Cover 68*47*2mm, Black PMMA 1 pcs
4 Remote Control Panel 165*90*4mm, Transparent PMMA 1 pcs
5 Left Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
6 Right Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
7 DC Motor 25GA 370 Metal 4 pcs
8 Motor Support for DC Motor 25 Series Metal 4 pcs
9 Shaft Connector Ф13.9mm*23mm/6mm Aluminum 4 pcs
10 Set Screw M3×5 Metal 8 pcs
11 Screw, Spring Lock Washer and Plain Washer assemblies M4×18 Metal 4 pcs
12 Screw, Spring Lock Washer and Plain Washer assemblies M2×8 Metal 32 pcs
13 Cross Recessed Pan Head Screw M3×8 Metal 34 pcs
14 Cross Recessed Pan Head Screw with Washer M3×8 Metal 16 pcs
15 Hexagon Nut M3 Metal 16 pcs
16 Hexagon Distance Holder M3×40 Metal 5 pcs
17 Hexagon Distance Holder M3×10 Metal 8 pcs
18 Hexagon Distance Holder M2×15 Metal 4 pcs
19 Hexagon Distance Holder M2×10 Metal 12 pcs
20 [Grove - I2C Motor Driver](http://www.seeedstudio.com/depot/Grove-I2C-Motor-Driver-p-907.html) 2 pcs
21 [RF Bee](http://www.seeedstudio.com/depot/RFbee-V11-Wireless-arduino-compatible-node-p-614.html?cPath=19_22) 2 pcs
22 [Grove - XBee Carrier](http://www.seeedstudio.com/depot/Grove-XBee-Carrier-p-905.html?cPath=98_16) 2 pcs
23 [Grove - Thumb Joystick](http://www.seeedstudio.com/depot/Grove-Thumb-Joystick-p-935.html?cPath=85_51) 2 pcs
24 [Grove - Universal 4 Pin Buckled 20cm Cable](http://www.seeedstudio.com/depot/Grove-Universal-4-Pin-Buckled-20cm-Cable-5-PCs-pack-p-936.html) 2 pcs
25 [Grove - Branch Cable](http://www.seeedstudio.com/depot/Grove-Branch-Cable-5PCs-pack-p-847.html) 1 pcs
26 Power Cable 100mm, Black 3 pcs
27 Power Cable 100mm, Red 3 pcs
28 RockerSwitch 1 pcs
29 T-shape Plug 1 pcs
1. BLE Version

Parts Name Specification Material Quantity
1 Chassis 250*145*5mm, Black PMMA 1 pcs
2 Upper Deck 192*145*5mm, Black PMMA 1 pcs
3 Battery Cover 68*47*2mm, Black PMMA 1 pcs
4 Left Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
5 Right Mecanum Wheel Φ60mm H32mm Aluminum&Rubber 2 pcs
6 DC Motor 25GA 370 Metal 4 pcs
7 Motor Support for DC Motor 25 Series Metal 4 pcs
8 Shaft Connector Ф13.9mm*23mm/6mm Aluminum 4 pcs
9 Set Screw M3×5 Metal 8 pcs
10 Screw, Spring Lock Washer and Plain Washer assemblies M4×18 Metal 4 pcs
11 Screw, Spring Lock Washer and Plain Washer assemblies M2×8 Metal 20 pcs
12 Cross Recessed Pan Head Screw M3×8 Metal 10 pcs
13 Cross Recessed Pan Head Screw with Washer M3×8 Metal 32 pcs
14 Hexagon Nut M3 Metal 16 pcs
15 Hexagon Distance Holder M3×40 Metal 5 pcs
16 Hexagon Distance Holder M3×10 Metal 4 pcs
17 Hexagon Distance Holder M2×15 Metal 4 pcs
18 Hexagon Distance Holder M2×10 Metal 6 pcs
19 [Grove - I2C Motor Driver](http://www.seeedstudio.com/depot/Grove-I2C-Motor-Driver-p-907.html) 2 pcs
20 [Grove - BLE](http://www.seeedstudio.com/depot/Grove-BLE-p-1929.html) 1 pcs
21 [Seeeduino](http://www.seeedstudio.com/depot/Seeeduino-V30-Atmega-328P-p-669.html) 1 pcs
22 [Base Shield](http://www.seeedstudio.com/depot/Base-Shield-V2-p-1378.html) 1 pcs
23 [Grove - Universal 4 Pin Buckled 20cm Cable](http://www.seeedstudio.com/depot/Grove-Universal-4-Pin-Buckled-20cm-Cable-5-PCs-pack-p-936.html) 1 pcs
24 [Grove - Branch Cable](http://www.seeedstudio.com/depot/Grove-Branch-Cable-5PCs-pack-p-847.html) 1 pcs
25 Power Cable 100mm, Black 3 pcs
26 Power Cable 100mm, Red 3 pcs
27 RockerSwitch 1 pcs
28 T-shape Plug 1 pcs

Specs for Motor

## Tech Support¶

Please submit any technical issue into our forum.