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-   -   Starting out with Swerve Drive. (http://www.chiefdelphi.com/forums/showthread.php?t=137054)

page2067 30-04-2015 15:26

Re: Starting out with Swerve Drive.
 
Our (Team 2067, Apple PI) swerve drawings and Labview code are posted on this page:

http://www.applepirobotics.org/useful-links/

We have used a similar system the past two seasons, It has been mechanically trouble free. It is based on using the older style 221 swerve modules, with custom gearbox for drive and steering inputs.

It is heavy, which may be a focus of offseason development, but we like the robustness. The COTs components (221 modules and many gears, and motors), have run for 2 seasons of districts (over 160 matches, plus 10's of hours of offseason demos, scrimmages and messing around) with little to no visible wear. (except for the wheels themselves last year)

We have limited machining capability - so the design is crude but can be made if you can drill a hole with some precision.

The Labview code posted is our third generation, a fourth will be posted later this year, but the changes are minor. We know of a few teams that were able to use this code out of the box.

PAR_WIG1350 02-05-2015 16:14

Re: Starting out with Swerve Drive.
 
On the topic of "where to start", one particular implementation deserves to be at least mentioned.
The original:
http://www.chiefdelphi.com/media/photos/12949

For development of hardware, this setup would be more cost effective, since you only need two modules. You could actually get away with one for pure hardware development. I suggest omnis in place of the casters.

asid61 02-05-2015 16:20

Re: Starting out with Swerve Drive.
 
Quote:

Originally Posted by Scott Kozutsky (Post 1478960)
There are several places you should look for awesome swerves that were not yet mentioned:

1717-IMO best swerve in FRC; light, well driven 2 speed, I don't know of any failures
http://wiki.team1640.com/index.php?t...rain_Team_Page

1640-excellent documentation. You can look up the design process and I believe CAD models all the way from where they started.
http://wiki.team1640.com/index.php?title=Swerve_Central

3928-the pioneers of cim in wheel swerve
http://www.chiefdelphi.com/forums/sh...d.php?t=104504

2451-continued development on neutrinos swerve
http://www.chiefdelphi.com/media/photos/40298

696-new swerve this year, very elegant IMO
http://2015blog.team696.org/?paged=7

aren hill personal swerve
http://www.chiefdelphi.com/media/photos/41030

I didn't link pics directly but you should be able to find some good stuff based on that.

I would argue 2451's swerve drive here is better than 1717's:
http://www.chiefdelphi.com/media/photos/40911

It's a variation of Aren's swerve, but shifting. Plus, they released the CAD for it.

MaGiC_PiKaChU 02-05-2015 17:37

Re: Starting out with Swerve Drive.
 
i've uploaded the file. Somehow CD won't allow me to create papers
https://drive.google.com/folderview?...Vk&usp=sharing

fovea1959 03-05-2015 21:38

Re: Starting out with Swerve Drive.
 
I'm having a little difficulty following here: are the arguments of "best" saying "best for competition" or "best for learning swerve on a tight budget"?

If we have a pile of CIMs and a Bridgeport (and the sharp students that know how to use it), how much much coin are we talking for swerve on a flyweight chassis (NOT a competition quality chassis)? How much machining time to go with it?

Dominick Ferone 03-05-2015 22:38

Re: Starting out with Swerve Drive.
 
we were looking into doing swerve, since we've done mecanum and love the maneuverability. The problem we have is where to start when it comes with machining, finding the parts, how to build custom gearboxes and the sorts. It was never an area touched by my team.

Also I have concerns with swerve taking a toll on the battery draw and a pushing match to cause our battery to die.(somehow we use already use a lot of power in a match.)

Bryce2471 03-05-2015 23:08

Re: Starting out with Swerve Drive.
 
Quote:

Originally Posted by fovea1959 (Post 1479707)
I'm having a little difficulty following here: are the arguments of "best" saying "best for competition" or "best for learning swerve on a tight budget"?

If we have a pile of CIMs and a Bridgeport (and the sharp students that know how to use it), how much much coin are we talking for swerve on a flyweight chassis (NOT a competition quality chassis)? How much machining time to go with it?

If your looking for a custom swerve drive that can be build quickly with only manual machines, I would recommend looking at our most recent design. Here is a link:
http://www.chiefdelphi.com/media/photos/41039

The first module was almost completely designed and manufactured in one week by a couple students and a mentor. It was build with only a manual Bridgeport and a table top manual lathe.

faust1706 04-05-2015 00:10

Re: Starting out with Swerve Drive.
 
Throwing something that one can do with swerve into this tread for visibility:

https://github.com/faust1706/Smooth-Swerve

It's a swerve adaptation of @notincontrol's smooth path planner/trajectory calculator.

ToMoPAnae 07-05-2015 09:15

Re: Starting out with Swerve Drive.
 
Quote:

Originally Posted by Bryce2471 (Post 1479736)
If your looking for a custom swerve drive that can be build quickly with only manual machines, I would recommend looking at our most recent design. Here is a link:
http://www.chiefdelphi.com/media/photos/41039

The first module was almost completely designed and manufactured in one week by a couple students and a mentor. It was build with only a manual Bridgeport and a table top manual lathe.

Thanks for sharing your design. This is going to be a lot of help to us moving forward because I think my team has all the machinery and knowledge to build something like this. Do you think you could post the CAD model or link to it so that the CAD students can see how it works?

Bryce2471 07-05-2015 15:28

Re: Starting out with Swerve Drive.
 
Quote:

Originally Posted by ToMoPAnae (Post 1480688)
Thanks for sharing your design. This is going to be a lot of help to us moving forward because I think my team has all the machinery and knowledge to build something like this. Do you think you could post the CAD model or link to it so that the CAD students can see how it works?

Sorry I forgo that the thread I liked doesn't have the CAD. Here is a thread with a CAD link:
http://www.chiefdelphi.com/media/photos/41070

I hope it's useful. Let me know if you have trouble pulling the files (I have never tested it myself) or if you have any questions.

chrisfl 07-05-2015 16:56

Re: Starting out with Swerve Drive.
 
Im also working on a custom swerve and i am not sure how to steer/mount it. It is modeled a lot like 221 systems and the wheel and turning module weighs roughly .9 lbs according to solidworks. I plan on mounting the system from the top. How do you mount coaxial swerve modules?

Scott Kozutsky 07-05-2015 18:31

Re: Starting out with Swerve Drive.
 
Quote:

Originally Posted by asid61 (Post 1479492)
I would argue 2451's swerve drive here is better than 1717's:
http://www.chiefdelphi.com/media/photos/40911

It's a variation of Aren's swerve, but shifting. Plus, they released the CAD for it.

I've seen both in person and personally prefer 1717s, it's lighter, more compact and has a longer track record of success. Also it seems easier to machine the wheels and to change the tread but I don't know that for sure. I wish the 1640 wiki had pics from their more recent iterations, they've made some nice improvements since 2012.


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