Mecanum Wheels: Why Forklifts (and Robots) Move Sideways
Have you seen those weird wheels with rollers on forklifts? Those are Mecanum wheels. They allow omnidirectional movement using vector physics.
Mecanum Wheels: Why Forklifts (and Robots) Move Sideways
You’re in a warehouse (or watching a sci-fi movie), and a heavy forklift drives sideways into a tight aisle. It doesn’t turn like a car. It slides. You look at the wheels. They aren’t normal tires. They are made of angled rollers. These are Mecanum Wheels (invented by Bengt Ilon in 1973).
The Vector Physics
A normal wheel pushes force Front/Back. A Mecanum wheel has rollers at 45 degrees. When the wheel spins forward, it pushes the robot Forward and Diagonal.
- Front Left + Rear Right spin Forward.
- Front Right + Rear Left spin Backward.
- The Math: Typical vector addition. The “Forward/Backward” forces cancel out. The “Sideways” forces add up.
- The Result: The robot moves purely to the Right.
The Trade-off: Grip vs. Agility
Why don’t all cars have them?
- Bumpiness: Driving on rollers vibrates.
- Efficiency: You lose about 30% of your power fighting the vectors.
- Traction: They have poor pushing power. A normal wheel beats a Mecanum wheel in a tug-of-war every time.
In warehouses, space is money. Being able to strafe sideways means you can pack aisles tighter. In robotics competitions, time is money. Being able to strafe sideways means you can dodge a defender without turning, keeping your shooter locked on the target. It is the ultimate “Agility Build.”