pic: our octanem drive

[zinthorne]

Originally Posted by zinthorne

We used transmissions which geared it down to 8:1 and then the extra big traction wheels with the 44 tooth sprocket helped give more power too. Same as in your design, our traction wheels lifted up the back mecanems about a half an inch.
This video has some pushing, and also a great upset win in finals.
https://www.youtube.com/watch?v=WbHHUtCGc1c

This link shows the shifting very well, and the pushing ability. You can see the front end lift up about an inch or two whenever I shift. You can also see how fast it is too.

Sorry, forgot the other link, this is from the driver station, so you can see the shifting very well.
https://www.youtube.com/watch?v=m93XfLe4fj0

[tStano]

Can you strafe with 6 mecanums? How? The physics aren't working in my mind.

[EricH]

Originally Posted by tStano

Can you strafe with 6 mecanums? How? The physics aren't working in my mind.

It looks like it's a mecanum drive with drop-down traction wheels, rather than a 6-mecanum drivetrain.

Now, I think a 6-mecanum drivetrain could work, provided that the center mecanums were matched to opposite corners--that is, the FL and the RR mecanum wheels are matched to the CL and CR mecanums, and are oriented the same way, either via chain or via programming, or some similar setup.

[tStano]

Originally Posted by EricH

It looks like it's a mecanum drive with drop-down traction wheels, rather than a 6-mecanum drivetrain.

Now, I think a 6-mecanum drivetrain could work, provided that the center mecanums were matched to opposite corners--that is, the FL and the RR mecanum wheels are matched to the CL and CR mecanums, and are oriented the same way, either via chain or via programming, or some similar setup.

OHHHH. This robot's a square, I thought the left side of the picture was just cut off, and now it makes a whole lot more sense. Thanks!

And I think you're right, but I think it'd be a mess to get the powers ratios right, because you've got 2 wheels on the ground fighting one. The weight balance would have to be super weird, or there would need to be a lot of math with traction forces, power draw, motor controller and motor curves, and stuff so you could manipulate power ratios so the forward components cancel when you strafe(and the sideways components do when you don't).