SuperShifters Question

[Vioxtar]

Can a robot with SuperShifters of 9/1 spin in place, without moving?

Many thanks.

[Racer26]

There are alot more factors to this.

What orientation?
What wheel configuration?
What surface material on the wheels?
What diameter are the wheels?
Is there any center wheel drop-offset?

[Vioxtar]

Originally Posted by 1075guy

There are alot more factors to this.

What orientation?
What wheel configuration?
What surface material on the wheels?
What diameter are the wheels?
Is there any center wheel drop-offset?

Could you please define orientation? Thank you.

The wheel configuration is two 12 inch pneumatic wheels on the front, and two 8 inch omni wheels in the back.

And what do you mean by center wheel drop-offset?

Many thanks 1075guy!

[BJC]

Your description should allow for turning about the 12" pneumatic wheels. Are you turning at all? Where is the majority of the weight on the robot? How are these SuperShifters connected to the drive wheels. I think we need more information before we can offer a solution.

Edit:
Drop offset Assumes a 6 or 8 wheel skid steer. Your problem doesn't correlate with most things that will stop a dropped 6wd from turning.

The first thing to do is to check your omni wheels and make sure that the small rollers can freely spin.

[Racer26]

Is your robot a wide orientation (38" front, 28" side), or narrow (28" front, 38" side)?

Center drop is a concept used in the West Coast Drive (6 wheels, 3 per side, with the wheels in the middle dropped 1/8" down from the others), to improve steerability.

Are all 4 wheels in your robot powered, or just the 12" wheels?

[EricH]

Orientation: Long robot or wide robot? (Wide robot has the wheels on the short sides; long has them on the long sides.)

Center drop is used with >4WD. When you don't specify a drive, someone's probably going to assume a 6WD drop-center drivetrain and ask about the drop. (Typically, the center wheel is a fraction of an inch below the others in that configuration.)

I'm inclined to agree with BJC--you'll spin around the pneumatic wheels. (Well, a point on the axle of the pneumatics, at any rate.) AFAIK, there is no way to avoid that with a 2-traction, 2-omni setup of your type. You can avoid it by changing the placement of tractions and omnis, but they'd need to be the same size to pull it off effectively.