pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Is there a hidden electronics pan, or was it just not CADed? The design is certainly interesting.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

There is a polycarbonate panel in the center for electronics, though it has not been populated in the CAD model.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

I always love seeing the swerve designs your team comes up with

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Can you show a closer view of module?
and discuss what metrics you (Nick) are going after?

Love PWNAGE swerves. an also always like the bevel edge bumpers.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Why did you go with a 775 on the VersaPlanetary for module rotation? What ratios are on it/speeds can this achieve?

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Can you post a link to the CAD? I can't find any links in the forum thread. Or at least give more in-depth directions to finding the link if one exists.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

[quote=page2067;1510664]Can you show a closer view of module?
and discuss what metrics you (Nick) are going after?]

I just posted two more pics for the swerve units themselves, should show up soon.
I think that Nick was going for lighter weight primarily and therefore less custom parts, assembly time, etc.

The two speed design we posted last year and used for 2015 were for games that required precision alignment or heavy defense games.
We found that the single speed unit we used in 2014 didn't have the power to get out of trouble for heavy defense, our main downfall at champs that year.

We thought precision alignment would be helpful last year since our original concept was to work with other teams and cap 3-4 totes and a can onto their 2-3 stacks. The swerves worked flawlessly, not a single issue all season on either the comp or practice bot. Just last month the students disassembled the units from the practice bot, cleaned them, inspected them and no noticeable wear was detected. The students reinstalled them into the practice chassis from 2014 to use as a development platform.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

The steering gearbox is a Vex Planetary with 100:1, then through a 40 tooth (this design and 36 tooth for the 2015 unit) into a 72 tooth which the wheel is attached to. 48 RPM steering speed at peak power for a 550 motor.

We have used 5XX series motors on both our 2014 and 2015 swerve drives for steering. I'm not sure why Nick used a 775, we have never had an issue with the 5XX series motor for steering. I am guessing it is because we had Nick setup our Versaplanetary gearbox in Solidworks with "Configurations" and he picked a different configuration.

To discuss configurations a little more. When designing the robot we can insert a Vex Versaplanetary gearbox into Solidworks and change it to any possible configuration. This is a tab that allows you to reconfigure an assembly automatically, once you've spent the time adding in all possible parts. You can hide ,surpress, change items in the assembly so that it "reconfigures" the assembly. We currently can change between single and double stage reduction. We can change between the Bag motor, RS550 and RS775 motors. We can change the output shaft options between the .375" hex, .500" hex, .500" round, and 8mm keyed CIM shaft. We can also change to a dual motor option. This all occurs with a click of a button on the same gearbox assembly. So there is no deleting and reinserting a new custom setup. There is no creating a custom assembly each time we need to insert a VersaPlaentary gearbox into the robot design. We should create a video sometime to show how to do this for the First community.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Kevin is correct, I put a large lexan sheet in center to mount electronics to as well as some smaller panels in those open side areas. I put the motor controllers in those side areas as they would be close to the swerve modules there. I chose not to spend time populating all the electronics in as that is always so dependent on the game as far as space availability and felt my time was better spent working on something else.

As Kevin mentioned, we as a team have one single assembly for every VP combo. I was working on this project on my personal computer rather than the Genesis Automation/team servers so when I tried changing the configurations I was having issues. I decided to just leave it as is since editing the VP in real life is very straightforward and could easily be changed to a BAG or 550.

I have some decent renders that show things pretty well, so I'll see if I can get those up here.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Here are a couple renders that show things a bit better.





Feel free to ask any questions. Keep in mind that there were/are still things I would want to improve on this design, I just found a stopping point and had some other projects I wanted to hit before the new season begins.

Sorry for the large images.

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Very nice swerve module, it is nicely packaged. I am really impressed that the motors are stationary in this design. I feel ignorant, but what separates a swerve drive from a coaxial swerve? What size wheel are you using and what are the drive gear ratios? Are all the gears stock? How much does the module weigh?

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Also, can you explain how the bearing surface works between the wheel module and the rest of the drive module?

Re: pic: 2015 Off-season Single Speed Coaxial Swerve Chassis
 

Are you guys willing to share your configurable VersaPlanetary assembly? If you're OK with it, I'd love to add it to the parts library I've been working on for my team and the FRC community.