mecanum wheels at 45 degrees

[pr0ph3t]

I was wondering, does anyone know if it's possible to mount mecanum wheels at 45 degree angles in the corners of the robot (like you would omni wheels) and achieve forward/backward/strafe/spin motions?

[Andrew Schreiber]

Possible: Yes.
Useful: No, Mecanums can already achieve those motions as they are (in a very simple sense) omni wheels mounted at a 45 already.

I suggest, if you are still not sure about your drive train that you pull out the KoP frame and put the KoP drive train together since you only have 1 week left.

[Joe G.]

Mecanum wheels generate a force at 45 degrees to their axis of rotation. Mounting them at 45 degree angles will add or subtract from this, depending on how you do it, creating either a 0 degree or 90 degree vector. In other words, tank drive! The resultant drivetrain would behave like tank drive, except be harder to build, have low traction, and suffer frictional losses from the mecanum rollers. Not exactly desirable...

[Ether]

Originally Posted by Joe G.

Mecanum wheels generate a force at 45 degrees to their axis of rotation. Mounting them at 45 degree angles will add or subtract from this, depending on how you do it, creating either a 0 degree or 90 degree vector. In other words, tank drive! The resultant drivetrain would behave like tank drive, except be harder to build, have low traction, and suffer frictional losses from the mecanum rollers. Not exactly desirable...

Well, if you swapped the rear left and rear right wheels, and then mounted all 4 wheels at 45 degrees, you'd have a rear-wheel-drive front-wheel-steering vehicle (with lots of frictional losses and poor traction).

[andreboos]

If you have a frame with wheel mounts at 90 degrees to each other (45 degrees from normal), you could use regular omni wheels:

(http://www.andymark.com/ProductDetai...ctCode=am-0013)

Mecanum wheels in that configuration would not be omnidirectional. Rotating the front right and back left wheels 15 degrees counterclockwise and the front left and back right wheels 15 degrees clockwise would provide more power in the forwards direction (I think) while retaining some omnidirectional ability.

[Ether]

Originally Posted by andreboos

Rotating the front right and back left wheels 15 degrees counterclockwise and the front left and back right wheels 15 degrees clockwise would provide more power in the forwards direction (I think) while retaining some omnidirectional ability.

If the reference from which you are rotating the wheels in the above is the normal mecanum orientation, then you have the clockwise/counterclockwise swapped.

[pr0ph3t]

Thank you, everyone, you've been most helpful.

[andreboos]

Originally Posted by Ether

If the reference from which you are rotating the wheels in the above is the normal mecanum orientation, then you have the clockwise/counterclockwise swapped.

Oops, I was mixing up my force vectors.