pic: 1625's swerve module (better pic)

[Aren_Hill]

loading photo ...

[Peter Matteson]

You're the only other team I've seen do welded tube construction wheels. I thought we were alone with that because everyong else seems to hog them out of a billet.

[wowmuffin]

Wow... those are beautiful. Are those wheels driven throught a screw gear or am I not understanding how the motor drives those wheels?

[A_Reed]

Originally Posted by wowmuffin

Wow... those are beautiful. Are those wheels driven throught a screw gear or am I not understanding how the motor drives those wheels?

It is done by changing the axis of rotation with a set of miter gears.

Nice setup, saw you guys on the MWR webcast, good looking robot.

[thefro526]

I like how you used snap-rings instead of collars. That has to save a lot weight.

[Aren_Hill]

Originally Posted by Peter Matteson

You're the only other team I've seen do welded tube construction wheels. I thought we were alone with that because everyong else seems to hog them out of a billet.

these are faster to make and are also most likely lighter and stronger in the places the force is applied.
its really easy to just waterjet the sideplates and weld them on, these wheels are 1.75" wide

Originally Posted by thefro526

I like how you used snap-rings instead of collars. That has to save a lot weight.

I LOVE SNAP RINGS!!! lol also the custom 7068 hex axles....not overkill at all...

[Peter Matteson]

Originally Posted by Aren_Hill

these are faster to make and are also most likely lighter and stronger in the places the force is applied.
its really easy to just waterjet the sideplates and weld them on, these wheels are 1.75" wide

Same reason we do wheels out tube and plate welded together.

[AdamHeard]

Originally Posted by Peter Matteson

Same reason we do wheels out tube and plate welded together.

How easy is it to hold the plates and tube concentric while rounding?

If it is just standard Al tube, how thick are the walls and how true to round is the outer surface?

[Peter Matteson]

Originally Posted by AdamHeard

How easy is it to hold the plates and tube concentric while rounding?

If it is just standard Al tube, how thick are the walls and how true to round is the outer surface?

We cut a relief pocket in the plate so that it over hangs the tube and tube literally snaps into the plate. This gives us wheels as close to concentric as possible to make. I'll dig up some pictures and grab a few of the evolution of the design when I'm at the shop today so you can see what I mean.
Pete

Edit:
http://www.chiefdelphi.com/media/photos/31104?
http://www.chiefdelphi.com/media/photos/31105?
http://www.chiefdelphi.com/media/photos/31102?
http://www.chiefdelphi.com/media/photos/31103

Pictures now up.
End Edit

[Aren_Hill]

Originally Posted by AdamHeard

How easy is it to hold the plates and tube concentric while rounding?

If it is just standard Al tube, how thick are the walls and how true to round is the outer surface?

We just used 4" o.d. 1/8th wall tube, and waterjetted the sideplates, due to the nature of a waterjet it puts a slight taper on things so when i had it make a
3.75 o.d. disc it pressed right into the side of the tube and held itself there solidly while it was welded.

they're as concentric as you'll ever need for wheels.

[sdcantrell56]

How are you keying the wheel to the axle. I'm planning on using that type of wheel next year and just looking to compare ideas

[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