Mecanum Wheel Traction

[spiffyspleen]

I was thinking of ordering a pair of these for my team. Does this provide more traction. Has anyone used these before or have suggestions for adding traction to Mecanum Wheels?

Here is what we are thinking of ordering: (Set of 12 black stepped rollers for 8" Mecanum wheel am-0632)

Here is an image.

http://www.andymark.com/PhotoGallery...ctCode=am-0632

[nitneylion452]

Are you making your own wheels?

Either way, mecanums generally don't have very good traction for pushing, or resisting a push. You can tighten the rollers to make them more resistant, but this will also diminish your strafing speed.

[Nathan Streeter]

Most mecanum wheels provide excellent traction; those rollers appear quite grippy... although I haven't used them...

The reason why mecanum drives can't push hard is not because the wheels have poor traction, but because each wheel pushes diagonally... in order for the robot to go in a straight line the directly opposing forces cancel, leaving a single resultant vector.

Essentially, finding grippier rollers won't significantly improve your pushing power or acceleration, that is a problem inherent to mecanum drives. Some people have improved their pushing through different means... I can see how tightening the rollers so they won't spin as easily would improve pushing force some. 190 (WPI) came up with a cool innovation that essentially used mechanisms like break calipers to lock the rollers to provide the pushing force of a standard drive.

Not sure if this is truly helpful or not, just trying to clear up what may or may not have been a misconception! :-)

[nitneylion452]

Originally Posted by Nathan Streeter

Most mecanum wheels provide excellent traction; those rollers appear quite grippy... although I haven't used them...

The reason why mecanum drives can't push hard is not because the wheels have poor traction, but because each wheel pushes diagonally... in order for the robot to go in a straight line the directly opposing forces cancel, leaving a single resultant vector.

Essentially, finding grippier rollers won't significantly improve your pushing power or acceleration, that is a problem inherent to mecanum drives. Some people have improved their pushing through different means... I can see how tightening the rollers so they won't spin as easily would improve pushing force some. 190 (WPI) came up with a cool innovation that essentially used mechanisms like break calipers to lock the rollers to provide the pushing force of a standard drive.

Not sure if this is truly helpful or not, just trying to clear up what may or may not have been a misconception! :-)

I do understand the basic physics behind the mecanum wheel drive system. I just assumed the OP was referring to pushing power/resistance as "traction." I was trying to explain that the rollers prevent the wheels from having a lot of pushing power. Thanks for the clarification, though! It's always good to pass some physics knowledge!

[Ether]

Originally Posted by Nathan Streeter

The reason why mecanum drives can't push hard is not because the wheels have poor traction, but because each wheel pushes diagonally... in order for the robot to go in a straight line the directly opposing forces cancel, leaving a single resultant vector.

In the forward direction, the "single resultant vector that they leave" has the same magnitude as the forward force of a standard wheel.

The reason mecanum drives can't push hard is that the reaction force of the floor on the roller, being aligned at 45 degrees, is greater than the forward vector... so mecanum wheels reach the traction limit before standard wheels do.

[klmx30302]

Our team has a set of mecanum wheels with these rollers on them. They are the same as normal rollers but with rubber spacers on the sides.