Chief Delphi - Swerve Drive Modules

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Re: Swerve Drive Modules

Quote:

Originally Posted by Siri (Post 1061030)

Test the living daylights out of it. Weigh it down, run it hard, long (lower voltage), and against defense. Complex components have a nasty habit of seeming really great until you actually need them to be.

And, just to clarify what I think a lot of people have been saying (I think you realize it): Don't build a swerve to test if you can do it. Build it to learn the skills you need to build great drivetrains: testing, troubleshooting, consistency, accuracy, robustness. (not exhaustive) Emphasize those lessons over the result of the actual device. They're more important, for FIRST and beyond.

I love it. :] That's an excellent way of putting it. If you don't mind, I'm going to use that when teaching younger and newer team members. And that is exactly why I wanted to build it in the first place.

Re: Swerve Drive Modules

Quote:

Originally Posted by buildmaster5000 (Post 1061112)

Others have said this and I will echo their sentiments: if you do swerve drive, it needs to be reliable, and built like a tank! We spend many hours at our (only) competition fixing little things that kept creeping up on our swerve drive system. Also, I have trouble believing that the module you disigned will hold up against any amount of side load (imagine a 200 lb robot traveling 20 fps raming you at a dead stop. If you are moving, that net speed goes up, and bumpers will not do everything.) without torquing or just sheering the ouput shaft. Personally, it was really a nice feeling to have the bottom assembly of the WildSwerve modules there, where we could not sheer the output shaft.

In addition, decide on a control scheme and programming strategy, and if at all possible, have the driver be the programmer. I both programmed and drove my team's swerve drive this past season, and I was able to quickly and easily diagnose software problems just because I knew the program so well.

If you are interested, I can point you to the team code from this year, as well as answer any questions you have via PM.

I really like that idea. Our current driver is graduating this year and our programmer (at least the one programming the swerve) is going into 11th grade with me. (next year will be my 5th year, so I have quite some experience.) I will talk to him about driving. Also, does your team use a 3 axis joystick or 2 axis and a potentiometer/dial? And we have 1717's code (on their website) so I think we're okay with regards to reference.

Re: Swerve Drive Modules

Quote:

Originally Posted by msimon785 (Post 1061181)

we have 1717's code (on their website) so I think we're okay with regards to reference.

Have you looked at that code yet?

Re: Swerve Drive Modules

Quote:

Originally Posted by msimon785 (Post 1061179)

No problem. Not to be a buzzkill, but just do realize you're trading making something potentially cool (which unfortunately likely won't work well enough) for concentrating specifically on what will help you next season.

The former seems to be most inspiring though, so who am I to complain. Just don't get discouraged if/when you don't accomplish the device's goal, because hopefully you do accomplish the learning & inspiration ones. If not though, I would consider a different course for the next off-season. Good luck, and you know where to find us if you need anything. :)

Re: Swerve Drive Modules

I would strongly urge you to consider designing and manufacturing a bulletproof, reliable 6wd before even considering trying a swerve drivetrain. It sounds like you guys have yet to master that so why make the jump to the most difficult drivetrain. While it's fun to design and think through, there is rarely a game when having the abilities of swerve outweighs the tradeoff of added cost, time to manufacture, time to code, difficulty of control, and reliability.

Re: Swerve Drive Modules

Has anyone suggested using Team 221's Revolution Modules?

If you've got your heart set on doing a swerve, you could always use 221's modules to take a large chunk of the hard (mechanically) stuff out of the equation then spend more design time on the frame, power transmission to the modules, steering and code.

Re: Swerve Drive Modules

Quote:

Originally Posted by msimon785 (Post 1061181)

Right now, we use a 2 axis joystick for the movement/strafing and another joystick for rotating around the central axis of the robot. As for a pot, we used the MA3 from usDigital. I caution you about being presumptious over programming/driving though. Make sure it will not tear your team apart if one person fills these two critical roles. Again, I must reccomend spending one year mastering a 6wd. You will make some mistakes, and the knowledge gained will help even more when you go to make a swerve. For my team, mechanical issues were the problem in the end, not the software. Make sure you don't forget either or else you will have a very expensive paperwieght come competition.

Re: Swerve Drive Modules

And if the goal is to see how your relationship with the sheet metal shop will work, maybe design a six wheel drive sheet metal chasis similar to 148, 217, etc. Still no small accomplishment but more likely to be something you can get working well enough to use in the competition season.