pic: 2605 Mecanum Drive

[Culvan Van Li]

Originally Posted by Mr. Lim

Yep:
http://youtu.be/pRc0LtIe5VI

It's hard to see, but when the robot sprints straight forwards or backwards, the wheels are spinning faster than the robot is moving. We expected it to happen when you are moving sideways or diagonally, but were surprised to see it happening when we moved straight forwards and backwards too.

This is an old movie from when I was a mentor on 1310. This was the last time I was personally involved with a mecanum drivetrain, so it was some time ago.

You are absolutely correct. The robot will move slower than the wheels are spinning. The forces are applied at a 45 degree angle to the movement of the wheel so the robot will move at a speed = wheel speed * Sin(45 degrees). That's 70.7% of the speed of the wheels.

If the rollers are too stiff then the robot may move faster than that forwards and backwards and slower sideways. If the rollers have low friction then a meccanum robot will drive the same speed sideways as forward.