Swerve Drives, Omni Wheels, X Drives, and a plea to stop trolling

with a swerve drive you can also have 4m powering the wheels, and just use one motor to swerve them, so it’s a 5m drive.

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that’s the power of a diff e. rential (or you can call him by his formal name, Mr. Rential)

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Yeah that’s another interesting design that I’ve heard about. Thanks for bringing it up

You generally don’t want to do that so that you can have each wheel change angle independently and you can do variable angles to get higher speed or torque in one direction, as was being discussed in the other thread before it got locked

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True but there’s still some benefit to that design, since you essentially have a tank drive that works in any direction and it’s not as complex as a Mr. Rential swerve. Tank, bendy drive, or Mr. Rential swerve would still be a better use of motors though in my opinion

Notably, as Kyle pointed out on vtow, x drives (and mec drives) only have 1/2 power in diagonal directions in comparison

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Yeah, there’s a tradeoff of complexity vs. performance/other abilities here:

In order of increasing complexity (and performance), at least imo is:
Tank
Mecanum
X-Drive/Bendy Drive
5m non-mr. rential swerve (as xenon described)
4m mr. rential swerve (like kyle made)
6m mr. rential swerve (with the 3 wheels but this is pretty questionably even an upgrade over 4m because you get the downsides of 3 wheels like unsteadiness but the upsides of having more pushing power)

Note: Mr. Rential is here used as a jokey name to refer to differentials, I just think its more fun

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Can someone explain how these differential modules work? It looks like a convoluted planetary gear system on both modules that Kyle made (also, does Kyle have an @ on the vex forums?)

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Could you, please, explain the difference between these to the rest of us, initiated in the secret drivetrain society code?

Because, when reading these names, I smh and keep hovering my finger above :heart: and :white_flag: icons, unable to decide which one to tap.

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nah, kyle doesn’t have an account even though I told him to make one

If you want to talk to him I’d recommend joining VTOW, where he’s pretty active

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bendy drive is a fun name for x-drive

Mr. Rential is a fun name for differential

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While a full fledged swerve drive is impractical for VRC due to the ruleset, a compromise in the form of a shifting x drive that can operate in both tank and x drive modes would be much more feasible. Here’s 2114A’s implementation from toss up: https://youtu.be/VpcXp7TV_FA

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image

Okay @Sylvie . Spill the beans. 5 hours of replying to the same topic is ridiculous

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Please try to keep the discussion on topic about swerve drives please!!
If you want to know what hes up to you should dm him

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Ok. It’s settled. Swerve drives are the coolest drivetrain ever!!! Practical? very! Possible? probably not. But that doesn’t stop them from being awesome!

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@mvas Looking through the comments I’m not necessarily sure if anyone has provided an answer to your question regarding differential gearing. To be honest I am completely unsure how differentials are implemented within VRC - if someone smarter than me is able to concisely explain a VRC differential I’d assume they’re some sort of wizard.
That being said, I have two videos that may be of use to you (And to others reading this post who are curious about differentials and drive systems).

“Spinning Levers” (Youtube). This video is from 1936 and goes over the basics of gearing and transmissions as they refer to automotive drivetrains.
“Around the Corner” (Youtube) This video is from 1937 and goes over the basics of automotive differentials.

Obviously these videos do not directly pertain to robotics, but may serve to explain some of the theory and practical applications of transmissions and differential gearing systems.

(As a side note, as previously stated by others Kyle does not have a account here on the forums. He, like me and others, can be reached through the VTOTW Unofficial Discord server. Though I won’t give you a link, it shouldn’t be terribly hard to find. I would advise sending a ping in the #hardware channel.)

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I’m on VTOW, I just don’t like spending much time on there.


This video explains them in the context of Vex pretty well. I was more so curious about the particular configuration made by Kyle. I do appreciate the feedback though and I’ve seen those videos before (they’re pretty great).
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Differentials can be done in vex, it’s just that the inability to use custom sized gears makes them very large and bulky, and not suitable for use

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(@mvas8037 )image

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Ahh I see, that’s really neat. It actually looks so much more complicated than that, but I see how it works now. I guess it’s nice to have a bit of background working with differentials before.