Best Drive Train

[Andrew Schreiber]

Originally Posted by jwfoss

...and is within the resources (cost, machining, etc) for your team.

Shouldn't those factor into your strategy?

Originally Posted by stingray27

Isn't tank drive the naming convention for the style of controls? Either way, if your using tank drive you MUST drop those center wheels. Otherwise the drive system will be useless because you wont be able to maneuver well...

NOT true at all. If your wheel base is wider than it is long... or actually, just read Chris' paper http://www.chiefdelphi.com/media/papers/1443

[stingray27]

Originally Posted by Andrew Schreiber

Shouldn't those factor into your strategy?



NOT true at all. If your wheel base is wider than it is long... or actually, just read Chris' paper http://www.chiefdelphi.com/media/papers/1443

Sorry my version of tank drive has been corrupted over the years due to how we ALWAYS have had 6-8 wheel drive and a long bot at that.... forgot about the wide bots....

[Jacob.B]

On Truck Town we like tank because it works well with our transmissions that shift from low to high gear. But I would like to experiment with other drive systems and wheels, because who wouldn't want to use beast wheels like 25?

[Jacob.B]

But I also like mecanum, maybe not for our team, but for other younger teams. They get the versatility that they want without taking on the challenge of swerve, that some of the best, most experienced teams can't conquer. Just like 2010! *shutters*

[fb39ca4]

Where is the warp drive?

[stoutman777]

Definitely 1625's lobster drive from 2011. That's my favorite.

[Mykey]

Obviously there is no "Best" drive train. There is only best for you.

We went with what we dubbed the "Chicken Drive". It is a 6wd tank drive with super shifters. What made it distinctive was redundant chains. We actually busted a drive chain in Newton qualifiers but kept running. Using pneumatic shifters was also very useful. We saw people at regionals trying to shift with servos and that meant they had to basically come to a full stop to do so.

[Rangel(kf7fdb)]

Definitely not the best drivetrain but a very very good one is this year's KOP Belt Drivetrain. We decided to go with it this year to spend more time on our different mechanisms. It took roughly 2-3 hours to put together and after we assembled it we never had to worry about it again. The built in belt tensioners worked great and once tightened we never had any problems with the drivetrain itself. Being able to not worry about the drivetrain at competition was a luxury we never had before. I would also like to point out just how robust it was. We could go head to head with some of the best drivetrains in frc. Fast, enough traction to not get pushed around, and very robust. Thank you Andymark!

[Clem1640]

We are big fans of swerve as a drive-train well suited to a wide variety of FRC situations. The ability to vector drive force in any desired direction is particularly valuable. So is the independence between chassis orientation and direction of movement. Some moves are shown in the attached link:

http://www.youtube.com/watch?v=Pej5pkFvFdY

Swerve does "cost" more. We use 4 drive and 4 steering motors and the overall weight of four pivot modules is 31.6 lb (includes all motors). Also, there is a significant investment in driver training. Despite this cost, we find that the benefits that this versitile drive-train provides to us in competition makes it worthwhile.

[Jared Russell]

Given infinite time, money, motor selection, programming ability, manufacturing ability, and driver practice time...swerve.

The more of those assumptions you relax, the more attractive plain old tank drive starts looking.

[cadandcookies]

I would say the best drive train is this:

http://www.chiefdelphi.com/forums/sh...shed%2C+around

I mean, look at that-- robust, light, simple...

[42!]

Don't forget about the fact it can travel over 100 fp/s

[Tom Line]

Originally Posted by Andrew Schreiber

Shouldn't those factor into your strategy?

NOT true at all. If your wheel base is wider than it is long... or actually, just read Chris' paper http://www.chiefdelphi.com/media/papers/1443

We had Chris come in and give a seminar at Michigan State Championships on drivetrains. His insight is pretty amazing. He actually talked about this paper, and how it really no longer applies to FIRST robots. It'll tell you if you can turn, but beyond that the physics don't really work with FIRST anymore. The paper was written when teams used metal cleats that acted very different than roughtop does now. He went into the friction characteristics of interlocking materials versus ideal ones, and talked about torsional stiffness, weight placement, etc.

For instance - a major mistake our team has made twice is to directly center the weight in a 6 wheel drivetrain over the center wheel (2011, 2013) on a semi-tall bot. The result is a robot whose center of gravity constantly shifts. That creates a really ugly chatter through turns even with a very stiff frame. It also doesn't like driving straight because the weight shifts when you accelerate then shift forward again when you hit the brakes. It was really eye-opening, and explained why our driver spent the majority of the year driving with only two wheels on the floor