pic: 1625's swerve module (better pic)

[A_Reed]

how is the lower plate supported? I know it used as a bearing surface, but it is sandwiched between plates or riding on small ball casters. I have always wondered how this work with swerve modules, I understand the rest of it but the lower support plate is the only gap in my limited knowledge of drive systems(I don't go into the kinematics...yet).

[hillale]

Originally Posted by A_Reed

how is the lower plate supported? I know it used as a bearing surface, but it is sandwiched between plates or riding on small ball casters. I have always wondered how this work with swerve modules, I understand the rest of it but the lower support plate is the only gap in my limited knowledge of drive systems(I don't go into the kinematics...yet).

The lower plate isn't necessarily a support plate, just a bearing surface like you said. Due to the nature of friction, it does a little support, but mainly it just rubs against flat plastic patches (lubed up to reduce friction) on the frame to aid in steering the modules. The face of the contact between the plastic and the plate is purely vertical. No horizontal contact is made between the plate and the frame. It is welded, in the corners, to the square tube that makes up the vertical body of the module.

[Un Luchador]

With such an effective drivetrain, it's no wonder you guys went undefeated at Colorado. I love the way you guys keep the robot chassis facing forward through the match, but still have the swerve function to put you back into position. That's very innovative.
Keep up the hard work and military-like competing guys.

[Jimmy Cao]

That module looks very simular to our initial idea, except we were putting the motor/transy inside the module itself.

It's very nice looking =D

[hillale]

Originally Posted by Lostmage333

That module looks very simular to our initial idea, except we were putting the motor/transy inside the module itself.

It's very nice looking =D

That's what we did last year, we had a cim mounted vertically through a dewalt on each of the modules. This coaxial design made maintenance much easier (though it has gone through 3 regionals and hasn't broken once). Here is a pic of our underbelly, http://www.chiefdelphi.com/media/photos/28596. I guess we don't have a closeup of the module from last year.

[Aren_Hill]

This guy weighs in at 2lbs 14oz and i coulda taken a couple more ounces out of the steel sprockets. Lighter than last years

[lukevanoort]

Originally Posted by Aren_Hill

i coulda taken a couple more ounces out of the steel sprockets. Lighter than last years

Have you thought about going to aluminum drive sprockets to save a touch more weight?

Originally Posted by Aren_Hill

This guy module weighs in at 2lbs 14oz

Is there a girl module?

[Aren_Hill]

Yes i have but during the season i was too busy to find a supplier or someone to have them made.

[Elgin Clock]

Aren, do you have a white paper on this, or at least a picture of the other side of this assembly showing the bevel gears?

I got to see this up close at IRI, & was very impressed.
Not only did it perform great on the field, but it was relatively lightweight for what it consists of.

I'm trying to convince my teammates to experiment with as many drive trains as possible over the summer with our upcoming test chassis, & want to show them this one as a great example of swerve assembly.

[Aren_Hill]

I myself do not own a camera, and if i did wouldn't have time to take pictures.
The module structure (alum parts) is almost all waterjetted parts, then welded onto a 3x3x1/8th wall tube that had bearings holes CNC'd into it.

it will have some revisions for next year if we continue to do swerve, such as better bearing support at the top. (right now 1/2" bearings are taking the thrust load....). I'm considering copying 148's wheels so we dont have to worry about retreading and steering the wheels would be easier

Originally Posted by Aren_Hill

This guy module weighs in at 2lbs 14oz and i coulda taken a couple more ounces out of the steel sprockets. Lighter than last years

Hm, you should switch to Kevlar belting and aluminum pulleys. Then this setup would be truly frighteningly light. Out of curiosity, how many teeth does your steering sprocket have? I'm currently designing a bottom support crab, so I can finally post one that doesn't get hit with the "you're not supporting it right" complaint.

[Aren_Hill]

Originally Posted by A_Reed

how is the lower plate supported? I know it used as a bearing surface, but it is sandwiched between plates or riding on small ball casters. I have always wondered how this work with swerve modules, I understand the rest of it but the lower support plate is the only gap in my limited knowledge of drive systems(I don't go into the kinematics...yet).

the bottom disc is simply supported by 4 tangential pieces of UMHW (ultra high molecular weight) plastic, that we keep white lithium grease on all the time to keep it slick. Rollers are more efficient but take longer to install and are heavier