Re: Truly omnidirectional omniwheels?
 

That's true of any wheel, so I don't really think it's a valid concern about omniwheels in particular.

Re: Truly omnidirectional omniwheels?
 

You can't have the full wheel rotation coupled with the roller rotation to move omnidirectionally if the full wheel can't roll. That's the point there.

Re: Truly omnidirectional omniwheels?
 

the hex drive train that you're talking about would definitely work with traditional omni wheels. you're right about the wheels not being able to free-wheel when the motor is unpowered, but this is a good thing. you want the rollers to only free-wheel in a direction that has another powered wheel opposing it, so that the powered can control motion in that direction. if the rollers swivel, then the drive will be difficult to control, and will have virtually no traction (how much traction does a desk chair get?).

i'm sorry if this doesn't make sense; omni directional drive trains are difficult to explain without delving into vectors trigonometry.

Re: Truly omnidirectional omniwheels?
 

I guess I still don't understand the point. Are you trying to make an omniwheel that rolls freely in every direction? A standard omniwheel does that. Are you trying to make an omniwheel that rolls freely in every direction even when it's prevented from turning around its main axis? That would work exactly against your reason for locking the drive shaft in the first place.

Re: Truly omnidirectional omniwheels?
 

I think he wants an "omni"wheel that will roll freely in every single direction except forward/backward. (Thus, the motors will still drive the wheel along one axis.)

With traditional omniwheels you can push them only sideways if the driveshaft isn't moving. With the wheels he's talking about you could still push the wheel at a 45 degree angle with forward being 0 degrees.

It wouldn't have very much traction though, but I think that's the point.

Re: Truly omnidirectional omniwheels?
 

Yeah, that's what I'm going for. Of course, a more senior team member is telling me I'm dumb, so most likely it won't ever happen. Of course, I can still dream.

The locking of the motors would still have its intended effect because from almost any angle there would be wheels going forward or close enough forward so that the wheels wouldn't let it roll. Or something akin to that.

And Roger, I'm afraid I can't... really visualize your statement of the problems. Someone needs to invent a machine that visualizes thoughts and sticks them on a screen. To be used for purely scientific purposes.

Re: Truly omnidirectional omniwheels?
 

They have... and i believe it's called microsoft Paint. ;) I can't visualize very well how this differs from a normal omnidrive except that it has 6 wheels... and powering 6 wheels will be a challenge since you dont have 6 identical motors.

Re: Truly omnidirectional omniwheels?
 

Are you talking about the brake/coast jumpers on the victors? You can set the jumpers on the speed controllers to short the motors with a neutral command (127), this causes them to brake. You can also set them to coast on neutral, which lets the motors free spin. The jumper block is right below the PWM cable port on the victor.

Re: Truly omnidirectional omniwheels?
 

Use 2 motors total, and use two of them to power all 6. We this year had 4 wheels, two motors. One wheel was direct drive from the gearbox, the other was 1:1 ratio chained with the other wheel that was direct driving.