Swerve Drive Idea

[The Analog]

I'm designing a robot, and have decided to implement a swerve drive. I'm loosely basing the swerve modules on 221's Wild Swerve. These modules have a CIM motor, and gear box on the pod. I would like to be able to turn these modules without any restriction, but those darn wires will get in the way. So, I was thinking of a way to solve this issue, and this is what I came up with.

place 2 stationary metal rings around the module, so it can turn freely, then use pvc, or something to that effect to rout the wires from the CIM to the ring, then attach the wire to a metal wheel and axil assembly (like one on a model train) and use the ring like a track. The ring can then be attached to a Jag/Victor with stationary wires.

This entire assembly, can then be encased in lexan/plastic/something to keep hands away from current.

I would love to here what you think about this idea, any improvements, and/or any constructive criticism

[Madison]

You're looking for something called a "slip ring."

What you've described is a rudimentary sort, but you can purchase something to do the job as well.

[Andrew Schreiber]

Originally Posted by Madison

You're looking for something called a "slip ring."

What you've described is a rudimentary sort, but you can purchase something to do the job as well.

Bearing in mind they were illegal this year in FRC and may continue to be in the future.

[The Analog]

something like that, but the ones I've seen, wont go around the swerve module, see,

Originally Posted by Andrew Schreiber

Bearing in mind they were illegal this year in FRC and may continue to be in the future.

I seem to have missed this. Under what rules were they illegal?

[The Analog]

Originally Posted by Andrew Schreiber

Bearing in mind they were illegal this year in FRC and may continue to be in the future.

This is not a FRC bot, so I'm not too worried about the rules, but I would like to find a solution that COULD be implemented by teams

[AdamHeard]

They were legal in 08.

[Andrew Schreiber]

Originally Posted by CraigHickman

I seem to have missed this. Under what rules were they illegal?

I'll double check this but I do recall reading something about it, I could just be remembering something else.

EDIT: http://www.chiefdelphi.com/forums/sh...07&postcount=3 Al made the comment from a Q&A answer. It says R47 but I don't have a rulebook in front of me.

Originally Posted by AdamHeard

They were legal in 08.

Yup, and 190 used them well.

[ajlapp]

It may be easier to make a hollow main pivot axle so that you can pass the wires out the top of the module.

A few teams did this sort of modification to Wild Swerve units this season.

frc20 is one that comes to mind.

Originally Posted by ajlapp

It may be easier to make a hollow main pivot axle so that you can pass the wires out the top of the module.

A few teams did this sort of modification to Wild Swerve units this season.

frc20 is one that comes to mind.

We did this for our Swerve for Triple Play, and it didn't end well. Eventually the wires will twist and fray, even with programming constraints to avoid as much steering and overturning as possible.

[ajlapp]

We did this for our Swerve for Triple Play, and it didn't end well. Eventually the wires will twist and fray, even with programming constraints to avoid as much steering and overturning as possible.

Agreed, this can be an issue.

I recall frc469 in the past few seasons auto unwinding their swerve modules when they were sitting still to avoid wire issues.

You can always go coaxial.

[The Analog]

Originally Posted by CraigHickman

We did this for our Swerve for Triple Play, and it didn't end well. Eventually the wires will twist and fray, even with programming constraints to avoid as much steering and overturning as possible.

This is what I'm trying to avoid, I want to be able to make an infinite number of turns, and not have to worry about the wires. I think that by having stationary rings, and in turn, stationary wires, this will prove to be far superior.

I have looked into 118 swerve drive units, but I like larger wheels, and the dual chain drive just seems unattractive to me.

[Dave McLaughlin]

Team 190 used homemade high power slip rings for their arm in 2008. I believe they worked quite well. If you want more information I can ask someone who was on the team in 2008 to PM you.

[JewishDan18]

Team 20 had code to center the wheels whenever they are sitting still. They could rotate 1440 degrees total (2 spins either way, limited by the 10 turn pots). We had no noticeable damage to the wires after 3 competitions. We were planning on using magnetic encoders to detect position plus slip rings to have unlimited spins, but that didn't work out.

Originally Posted by The Analog

This is what I'm trying to avoid, I want to be able to make an infinite number of turns, and not have to worry about the wires. I think that by having stationary rings, and in turn, stationary wires, this will prove to be far superior.

I have looked into 118 swerve drive units, but I like larger wheels, and the dual chain drive just seems unattractive to me.

This might sound harsh, but if "attractiveness" is a heavy design influence for you, you might want to examine your design expectations...