Learning and Understanding different drivetrains

http://www.chiefdelphi.com/forums/sh...9&postcount=19

Post I made a while ago with a decently large amount of information on drive systems.

[Kabir Manghnani]

A well done WCD can give a team a pretty good step up from the competition for a lot of reasons that have been mentioned above and i dont think i need to delve into here but it does seem like your team is looking to take it to the next level (correct me if im wrong). Finding a consistent drive base and sticking with it isn't a bad thing, it gives you time to perfect your manipulator(s) which can really help your gameplay. But if you are looking to upgrade here are a few options to mess with in the off season.

1) 2-Speed gearbox: If you haven't already started using one it can really help your game play. Our team has loved the ability to race across the field and push people around at the other end if we need to once we get there

2) Integrated Manipulators: I actually missed it at SVR in 2013 but Team 118 (go watch their video, its brilliant) had a pick up that (this is what it looked like from their reveal video) dropped out of the bottom of their drivetrain. (Now that's cool) and its was a intresting way to keep from getting their pick up smashed.

3) I'm not even sure: Look to 118's drivetrain this year. In their reveal video this year (https://www.youtube.com/watch?v=PtRewwr59d8) just at around 15 seconds. Its amazing system but what happens is that omni's fire down using pistons and its got three great usages that i can imagine. A) Just as they do in the beginning a launch to really get you going might be helpful. B)Lets say you are getting defended and pushed across the field, you've got no traction at this point and even though you can get your wheels moving you cant get out of the push (ask your drivers about this, they know the situation) you fire down the omnis and just coast away, while ramping up your wheels and as soon as you coast out of their reach you sprint out of the way, freeing you from the pin. C) Turns, the ideal turning system would be high traction in the back and omni's where you want to turn right? So... fire down just one set of omni's (Look to 1:06 in the video) they manage to pull of these almost diming maneuvers throughout the video which i can only imagine happen because of the turning help that the omni's provide. This must be an incredibly powerful set of pistons and some fairly complicated code to make it easy to use but its a great summer program.

I'm reminded of a quote by Adam Heard of 973 (Correct me if I've got the wrong person) "World Champions are build in the off-season."

Good Luck!!

[Joseph Smith]

Originally Posted by Ether

Just to be clear: wheelbase is the distance from the front to rear axles (length). trackwidth is the distance between the two front (or rear) wheels (width).

Thanks, I'll remember that.

[Monochron]

Originally Posted by Joseph Smith

#2: Standard West Coast Drive.
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CONS: [...]
Requires more machining capability

What extra machining capabilities are required for a WCD? As far as I have seen it looks like you can purchase most all of the parts required from dealers?

I ask because my team is looking into making the switch to WCD next year but we have virtually no machining capabilities.

[Rauhul Varma]

Originally Posted by safiq10

Currently we are stuck on West coast drive... We are absolutely stumped on what benefits it gives and why we see some of the more elite teams using it?

A west coast drive provides a ton of advantages. As others have said, you can maximize your wheel base, improving robot stability. It also can make servicing a drivetrain insanely fast. Our modified WCD set up allows us to switch out our entire drivetrain for entirely new components in under 10 minutes without having to temporarily remove/loosen any non drivetrain component.

[Madison]

Originally Posted by safiq10

Now in an effort to learn more about FRC and better understand it we are currently conducting research about the pros and cons on drivetrains. We want to understand why teams use a certain drivetrain.

Currently we are stuck on West coast drive... We are absolutely stumped on what benefits it gives and why we see some of the more elite teams using it?

Think of things in more atomic terms than 'drivetrains' and you'll be much better at understanding why teams have arrived at certain styles of drives and what the trade-offs were that led them there.

There's nothing intrinsically good about 6WD or swerve or anything else; good implementations are the result of well-considered details.