Falcon 500 in-wheel Swerve

https://grabcad.com/library/falcon-500-in-wheel-swerve-2

A concept I’ve been working on for the past 2 days. Honestly, I feel like it’s getting too complicated, and I might reboot the whole design and try to go for something more like pic: NEO in wheel swerve concept

Anyone have advice, comments, etc?

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I love it, buuuuttttt

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never on God’s green earth would I ever, EVER consider building that.

EDIT: Cool asf, though!

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Is that holes drilled through Colson rubber to mount the wheel?

I’ve never thought of doing a wheel that way. Pretty rad.

I’d be real worried about the bolts bending and the wheel rubbing on the motor.

Is that holes drilled through Colson rubber to mount the wheel?

Yes, through both the outer wheel and the inner core.

I’d be real worried about the bolts bending and the wheel rubbing on the motor.

That shouldn’t be an issue unless there’s something like a level 2 hab drop. If each wheel supported an entire 120 lbs, even with aluminum tubes, they would only bend .004 inches. Replacing them with steel reduces that to .001 inches.

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GG on the CAD but I would never be able to build this since our second-year team is going to be building a :b:asic drivetrain.

As someone who has used motor-in-wheel swerve before; don’t.

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Why? And why did 2451 use it (2014, right)? The coolness factor? The low cg?

That was fast. You can always depend on CD for some quick inspiration days after a product announcement!

Seriously though, good work, I’m impressed.

How do you get power to your motor in the wheel?

They are using a device called a slip ring. They are really cool when used in the right applications.

Edit: In this application they may not be using a slip ring and are simply planning to rotate only a few times in any direction so as to not wrap the wires up.

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Aren Hill designed the first in wheel swerve that I know of, the year previous to ours in 2014. A lot of our students were friends with the Winnovation students and were really geeking out on Neutrinos swerve which is where Aren and some of our students landed for college.

I used his design as inspiration to design the Pwnage version.
I can’t remember the exact reasons for us doing what we did besides the fact that it was a neat design that caught our attention and made us want to try it out.

The delrin rollers on the end caps of the CIM for bearing the load of the robot instead of a steel sleeve around the CIM, the internal ring gear reduction instead of belt reduction and the prox sensor counting teeth for speed feedback were some of the differences to Aren’s design. But in function they were very similar.

To add on to what Kevin said, the reason I wouldn’t run it again is in the age we are in, there just isn’t really a packaging or weight benefit to doing it over a more standard coaxial setup, and it has the drawbacks of needing a slip ring or limiting the rotation of the module, both of which are not ideal.

At the time when we used it in 2014, it was the module we had developed previously because of the reasons Kevin listed above, and it was a lower profile option then the majority of the standard designs that were out there back then, and 2014 definitely benefited from a lower profile package to deal with the large ball sitting above it.

Please note that many (but not all) slip rings utilize mercury, which is explicitly not allowed, per the blue box under R9 (2019). Anyone interested in using one should be sure to bring a datasheet to show that it’s not mercury based.

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Related, the first thing I’d test before buying any other component for this idea is whether CAN signals intact across the non-mercury slip ring

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We ran CAN across a slip ring in 2017 on a tank drive swerve module. Didn’t notice any issues with the CAN bus, but the module was kind of uncontrollable from a tuning perspective.

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First off, sorry for temporarily derailing a good technical discussion.
But I keep seeing the thread title: “Falcon 500 in-wheel Swerve”
and my brain keeps seeing “…500 INCH wheel…” THAT won’t work!

For reference, this is what a 500 inch (about 42 ft diameter) wheel looks like:

Meteor

OK, that is all. I just wanted all of you to suffer the same fate.

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The Missouri wind and power 180a 6 wire slip ring is the one I think 5006 and 323 were using. It is mercury free and 30a per channel. And about $30 each.

I’ve looked more than once for a higher current slip ring. I was looking today at Meridian Labs slip rings but I assume they are beefier and much more expensive, but they tout good signal quality. I suppose you could put the one above on 30a breakers and power two falcons plus CAN.

We used that slip ring as well. We had two power, two ground, and the 2 CAN wires (with a terminating resistor). Just don’t tell the other 1/2 of CD about the CAN bus abuse.

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