Strange Swerve 4.0 Triple Strange 1533

[ToddF]

We've been looking for a swerve module buildable with our resources. Our swerve drive project has been on hold until we got access to a CNC machine. With this being waterjet cut, we finally have a viable path to building our own swerve modules. I think we've got our next summer development project. I can't wait to see how this holds up in competition.

[Brainiac33]

During our build process, we tried to stay as organized and precise as possible, we made these layouts at a 1:1 scale with the actual pieces just so we had layouts of all our parts.



Here is a google docs link to a much higher-res pdf if thats easier to download and use.

https://drive.google.com/open?id=0B4...3hrcTJWa1AyTlE

[Brainiac33]

In order to make swerve even more accessible for any team, we wanted to make our code public and available for anyone to use on their prototypes and designs. Here is the link to our github: https://github.com/ecgrobotics/Strange-Swerve

[cad321]

Originally Posted by asid61

The only thing I can see bad about this in the long run is that it might be difficult to integrate a CIM into it, unless you weld a 3/8" hex onto the output shaft for the bevel gear.

What would prevent them from using a CIM on the current VP using the adapter sold by VEXPro?

[asid61]

Originally Posted by cad321

What would prevent them from using a CIM on the current VP using the adapter sold by VEXPro?

That's a really good solution, apart from increasing the height of the module a bit.

[iyportne]

Originally Posted by cad321

What would prevent them from using a CIM on the current VP using the adapter sold by VEXPro?

Nothing...the plan was to make a perfectly scalable module..the power choices and ratios are now all in the versa gearbox, not the mechanical structure. Everything from lightweight and lightning fast to slow and powerful.

I know we'll never win the CD debate about Swerve vs. WCD...but let me just say if you are designing Swerve for pushing matches, you're kinda' missing the whole point anyway.

[Lil' Lavery]

And the VersaPlanetaries v2 arrived just in time to swap out all the burned out 775 Pros!

Kidding aside, I'll be intrigued to see how the 775s hold up should this make it to the competition field. Pushing matches aren't the only time a drivetrain could experience high current situations, nor are they always entirely avoidable (especially in games with designated scoring areas and/or chokepoints).

I'll also be interested with regards to how the modules hold up to side loads on the wheels. This is a very aggressively packaged module, and it has custom bearings to boot. I'm wondering how well those bearings will deal with scrub forces on the wheels, and what potential there is for those forces to get passed even further up the module.

Certainly a very ambitious and advantageous take on a swerve module.

[Cothron Theiss]

Just now noticed that it's a 1/4" bolt serving as the axle. That seems a little thin to me, but if it works, that'll be great.

[dmpage318]

Originally Posted by Cothron Theiss

Just now noticed that it's a 1/4" bolt serving as the axle. That seems a little thin to me, but if it works, that'll be great.

You can't see it because of the spacers, but the bolt passes through a 1/2" aluminum tube.

[Brainiac33]

We have just finished assembling all four of the modules, and have them mounted to a base chassis. The final weight is 25.2 lb. for all four modules AND our base chassis. Just as a heads-up, we will be giving a presentation on swerve mechanics, design, and programing at the FIRST North Carolina FRC workshop at NCSSM on December 17th so join us if you can. In the meantime, here are some more pictures of our design!

[OccamzRazor]

This looks pretty compact and quite a bit easier to repair compared to what you had on the last robot. What was the overall weight of the last system minus the tank treads and whatnot?

What kind of power savings do you expect from the changes?

Can't wait to see this one at the workshop in Durham.

[dmpage318]

Originally Posted by asid61

How is the single reduction VP + 100 tooth gear working out? It looks like you're running something close to 10:1 x 100:36, which ends up around 576 rpm, which is very fast for a swerve module. I would change to a 2-stage VP, but that's about the only way I could see this die.

Both VP gearboxes will likely have a second stage added once we get all the modules together. We just put in single 10:1's for initial testing and you're right, it's EXTREMELY fast.

[Noudvanbrunscho]

Very very nice, reminds me of the module from 696 in 2015.
I have a question about your gears, are they custom made or where did you buy them?

And what is the total weight of the module?

[iyportne]

Originally Posted by Noudvanbrunscho

...I have a question about your gears, are they custom made or where did you buy them?

Only custom gear is the housing gear. All others are COTS. Note that housing bearing/gear design would be scalable to any turret, turn-table or arm pivot and prevent those frustrating (yet awesome to look at) sheared gearbox shafts.

[marshall]

Well done!