04-02-2009 22:11

Kingofl337

Re: pic: Rosie Robotics first time doing Swerve

You could have at least used vex encoders for the traction control !

Looks good, if you need any help with programming let me know. :-)

04-02-2009 23:04

=Martin=Taylor=

Re: pic: Rosie Robotics first time doing Swerve

Yikes!

Do you really need that much torque? 4 CIMs with a big reduction?

04-02-2009 23:27

Jetweb

Re: pic: Rosie Robotics first time doing Swerve

Those look like the standard Tuff Box© Gears to me? Thats just a guess though.

05-02-2009 00:20

Johnny

Re: pic: Rosie Robotics first time doing Swerve

The output and drive sprockets look like a 1:1 ratio; the cluster's appear to be a 12:1 reduction just from the looks of it. So yeah, basically tough boxes.

05-02-2009 07:44

psyco_klown

Re: pic: Rosie Robotics first time doing Swerve

Ya its toughbox with optional ratio to give us a 8.5:1

05-02-2009 07:54

Team 135

Re: pic: Rosie Robotics first time doing Swerve

Wow that seems like over kill when you have very low traction. We tested our robot and found that power has nothing to do with this game, even in a pushing match.

Looks good though

05-02-2009 08:19

Rosiebotboss

Re: pic: Rosie Robotics first time doing Swerve

Au contraire! Power has everything to do with the design challenge of driving on the "regolith"!!!

The control of the power, how it is managed and delivered to the wheel is the key. Whether you manage it through software or through multispeed gearboxes, the team that manages it most effectively will have a big advantage.

05-02-2009 08:28

Al Skierkiewicz

Re: pic: Rosie Robotics first time doing Swerve

Dana and Rosie,
Looks nice, that ring at the bottom really helps but needs to be a good bearing surface. Have fun!

05-02-2009 08:30

Rosiebotboss

Re: pic: Rosie Robotics first time doing Swerve

The pods will be nested into a matching "ring" of delrin.

05-02-2009 11:55

Enigma's puzzle

Re: pic: Rosie Robotics first time doing Swerve

those look excellent, what i was trying to get my team to build but it isnt currently working.

Gearing them down does give you an advantage, because you will never reach a top speed of a high speed gearbox why do you need it? a slower one makes for higher torque at lower speeds, usually it is a trade off torque for speed, but if you can never get enough acceleration to go full speed trading off for speed is useless. You may not need the torque either but if it ever came down to it the torque would be needed before the speed.

05-02-2009 12:07

MrForbes

Re: pic: Rosie Robotics first time doing Swerve

Very nice! Are you sure this is the first time you've done it?

05-02-2009 14:47

Woodworker88

Re: pic: Rosie Robotics first time doing Swerve

Those look very well-made, although the seem very large for the components they contain. I would have moved the gears inboard and tried to get things in a bit closer. That's what we did on 114 in 2005. Swerve modules tend to take up alot of weight and volume, so the smaller, the better.

Excellent work by any means.

05-02-2009 15:37

Lil' Lavery

Re: pic: Rosie Robotics first time doing Swerve

I understand what you're trying to say, but you need to think about that statement a little more.
The reason you're unable to accelerate is because you're unable to transmit torque (rotational force) effectively to the driving surface. Friction (specifically static friction) is the limiting factor in how much torque you can transmit. Having torque beyond that isn't going to help you much.

Applying more torque than your traction is going to cause slippage.

05-02-2009 15:50

Re: pic: Rosie Robotics first time doing Swerve

Those things are enormous! (and GORGEOUS!)

I'm curious, could you elaborate on some of your choices for doing this? Specifically, why mount the motor on the module?

05-02-2009 17:13

psyco_klown

Re: pic: Rosie Robotics first time doing Swerve

Well we were looking at trying to keep the weight centralized over the wheels. We also were thinking about suspension on the pods, it would be only 1/4 in travel anyways to absorb some of the vibration on the floor.

06-02-2009 09:37

Rosiebotboss

Re: pic: Rosie Robotics first time doing Swerve

One other factor on why the CIM is mounted in the pod is for the traction control system our code guys have been working on, each wheel needs it's own motor and this was the easiest way to provide a full range of motion as well.