pic: stangs swerve module

[Aren_Hill]

loading photo ...

[Cory]

It's Delrin.

It's a pretty cool little piece of plastic.

It's milled on both sides so that the profile mates with the frame mounted plate, and the opposite side mates with the plate attached to the bottom of the module.

[Travis Covington]

Raul told us it was a custom machined delrin/acetal ring.

Edit: Aww, too slow today I suppose...

[Aren_Hill]

thank you very much

i want to see one of you two 254/968 do a swerve drive because you practically make anything you do art (such as 1.3lb apiece gearboxes) and a swerve drive would be plain amazing.

[Al Skierkiewicz]

Aren,
We learned early on, that the crab modules (which are fully modular for ease of repair) need some additional bearing help at the bottom of the module. The delrin ring provides that bearing surface and is somewhat self lubricating. Any forces that would be transferred through the module top bearing are actually shunted by this bearing right to the base of the robot frame. By keeping the bottom movement to a minumum, the surface of the drive wheel stays flat on the floor and side forces do not cause the upper bearing to bind as the module is rotated during pushing from other robots.
Note: As photographed the module is upside down. As such, the bearing ring and plate are laying on the table. During operation both the ring and plate would be mounted in the same plane as(and mating with) the round base of the module.

[Aren_Hill]

Al on our swerve drive this year at the bottom of each module we had a disc and then 4 1"diameter plastic rollers which were kind of a pain and something i'm looking on improving next year. could you explain how you machine the delrin? rotary table? lathe?

[Al Skierkiewicz]

Aren,
I am on the electrical team so I am not sure. I believe they were cut on a CNC end mill. If you did not get a close look, they are a "Z" in cross section but the vertical and horizontal elements are at right angles to each other. I will check with Raul and find out for sure which method was used.

[techtiger1]

That looks awesome Wildstangs robots continually inspire my team to try new and diffrent ideas and do a first rate job when maufacturing. We used a similar idea for our arm turret this year to reduce the friction of a regular lazy susan design when rotatation our arm. Many people ask us what the "pink stuff" is on our robot, it's oil impregnated uhmw a type of plastic very similiar to delrin it's useful for making light weight bushings. Anyway I didn't know if the delrin was impreganted with oil or not just throwing an idea out there for next year.

-Drew

[Raul]

Yes, they are cut in a CNC mill out of a .375 inch think plate of Delrin.