pic: 1625's swerve module (better pic)
 

Re: pic: 1625's swerve module (better pic)
 

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.

Re: pic: 1625's swerve module (better pic)
 

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

Re: pic: 1625's swerve module (better pic)
 

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.

Re: pic: 1625's swerve module (better pic)
 

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

Re: pic: 1625's swerve module (better pic)
 

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


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

Re: pic: 1625's swerve module (better pic)
 

Yes, I loved your guy's setup when you brought over the spare module to compare to ours at MWR. It is a real slick setup, not to far from ours. Great job on the wheels, and I absolutely love the sprockets you guys use to steer. That is an amazing setup on that. Hawging out the middle of hte sprocket also has to save a ton of weight, and I liked the slotted holes in the sprocket (if I remember right) to fine tune each wheel's tracking before you went out onto the floor.
Malhon

Re: pic: 1625's swerve module (better pic)
 

Hey, I like it. They look great! Swerve drives are for me as a rookie pretty impressive just because of their advantages. I'll probably test my cad abilities during the off-season by designing one myself... I'll see but it's a nice piece of metal!

Chris

Re: pic: 1625's swerve module (better pic)
 

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

Re: pic: 1625's swerve module (better pic)
 

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?

Re: pic: 1625's swerve module (better pic)
 

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

Re: pic: 1625's swerve module (better pic)
 

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.

Re: pic: 1625's swerve module (better pic)
 

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

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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).

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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.