FRC Drive Trains
 

This hopefully is a simple question. I'm trying to look into drive trains a little bit for our team this year and I was just wondering if people could give a quick description of their favorite ones from previous years.

Thanks!

Re: FRC Drive Trains
 

An obvious choice is 254's drivetrain from... well pretty much any year. 1114 as well.

Bomb Squad (0016's) swerve drive for omnidirectional drivetrains.

And now for a more a aesthetic choice:

https://dl.dropbox.com/u/27736599/Ne...r/IMG_0510.png

Re: FRC Drive Trains
 

We love our octocanum drive train, and are modifying the design for implementation as a drive base going forward (with modifications every year, of course, for a wide variety of reasons). Our new design will be significantly less expensive, use more available parts, be easier to maintain (not that it needed maintenance at any point, but if it had...), and be lighter weight.

Love it, love it, love it!

Re: FRC Drive Trains
 

My favorite FRC Drivetrain is definitely 469's articulating pneumatic eight wheel drive from 2011. That thing was a MONSTER. The four inner wheels were fixed and they had ball casters under the outer four wheels so their drivebase didn't rock, and they could engage the four outer wheels against the carpet with the push of a button.

TL;DR: If you were in 469's way in 2011, you were getting pushed, no questions asked.

Re: FRC Drive Trains
 

The middle four wheels are fixed.

The front and rear pairs of wheels are pneumatically lifted or lowered
The front and rear wheels also have pneumatically actuated ball castors next to them, just inside the inner frame rail. I don't remember the exact pneumatic setup, what was independently controlled and what was not.

They also used 3-speed Dewalts that year, servo shifted. They switched to Supershifters this year.


That drivetrain was HEAVY.

Re: FRC Drive Trains
 

You always gotta love 254's WCD. Same goes for 1114's drives. My personal favorite though is 1717's swerve.

http://www.chiefdelphi.com/forums/sh....php?p=1173487

Re: FRC Drive Trains
 

33's 2011 Drivetrain, as shown in this powerpoint.

Re: FRC Drive Trains
 

I've always been a fan of the 148/217 Nonadrive as well as the 148 Tumbleweed but, for my vote on completely reinventing omnidirectional drive would be 1625's Lobster Drive, which they did the year after they drove 6 wheel swerve on Einstein.

Re: FRC Drive Trains
 

I hate to toot our own horn, and I love 469; but we pushed them in 2011.

Re: FRC Drive Trains
 

You pushed everyone in 2011.

Re: FRC Drive Trains
 

Team 25's drive train from pretty much any year. With that drive train you can push anything. Also it's a locking drive train as well

Re: FRC Drive Trains
 

Thank you!!! Gotta love CD for doing some quick research :D As much as I love that 469 drive train, and some of 254's, can anyone think of some slightly simpler ones like 33's Dual Drive. Our team has limited machining capabilities and we usually need to use the K.I.S.S. strategy.

......Although I would be in favor of an 8-wheel articulating swerve drive with pneumatic brakes ;)

Re: FRC Drive Trains
 

There's been many drivetrains over the years I've really liked (some decidedly more successful in practice than others)

2003: 45 built a "Ball Drive" that worked a bit like an old ball mouse, but instead of the ball being the input, it was the output. (IIRC this wasn't their competition bot, but rather a proof of concept)
2003: 1075 built a "reverse snowmobile" (two undriven wheels at the rear of a wide orientation bot, and the front was a steerable unit not unlike the belt of a snowmobile)
2006-2008: 1075 built several incarnations of a belted longbody tank drive, with the CIMs inside of the belt.
2010: 1625's 6-wheel swerve
2010: 1075's Invertable swerve
2010: 1114's PTO-lifter
2011: 148/217's Nonadrive and its variants

Another drive concept I'm not sure of its origins:
Kiwi Drive (3 omni wheels, 120deg opposed)

Re: FRC Drive Trains
 

My favorite drivetrain is one that works consistently and requires little to no work to maintain. The Kitbot on Steroids (with Colson wheels) would be about as simple and solid as you could get.

Re: FRC Drive Trains
 

Kitbot on Steroids with Colsons. There's nothing better in terms of effort to reward ratio. You might never have to do maintenance on it.

Re: FRC Drive Trains
 

Just as a heads up: FRC Designs has a range of different drive trains to check out.

FRC Designs: www.frc-designs.com
FRC Designs Drives Page: www.frc-designs.com/drives.html

Re: FRC Drive Trains
 

Wouldn't using the kop wheels be equally reliable in terms of wear, but require less cost and effort?

Re: FRC Drive Trains
 

Colsons are nice but I agree that if you are just going with a kitbot, why use colsons? The new Higrip wheels are superior to previous FIRST wheels but investing in Colsons is $180 for hubs and wheels. As a rookie or low resource team I'd rather invest that $180 into other parts of my robot considering I'm already given reliable/comparable drivetrain.

Maybe the future kitbot on steriods is upgrading to supershifters?

Re: FRC Drive Trains
 

You're certainly right, especially with the new HiGrip wheels that are in a similar ballpark to Colsons. I mentioned Colsons to contrast with the common suggestion to upgrade to a treaded wheel, as tread does add some (arguably negligible) regular maintenance to the system.

Re: FRC Drive Trains
 

I've never seen a Colson wheel throw a tread or experience a broken spoke.

Re: FRC Drive Trains
 

It seems to me that the OP had a specific drive train in mind given his constraints before the first reply was made. Resources for learning about this type of drive train exist in several places -- only the specific teams numbers do not. Yet even with pictures of specific teams' drive trains, the OP won't have a full picture. That type is the 6WD Skid Steer. You want to use "KISS" as a mantra? There's no need to even look at Octocanum (FRC525 & others), Slide Drive (lots of VEX teams), Crab/Swerve Drive (FRC1717, FRC118, so many others), Twitch Drive (FRC1565 in 2008, FRC1885 in 2009), Ball Drive (FRC45 a long time ago), Mecanum Drive, Omni Drive, Car Steering Variants (FRC34/FRC1629 in 2008) or NonaDrive (FRC148).

What the OP needs are tips & tricks to make a simple drive train successful without having to go through the painful experience of learning everything himself (though this list isn't comprehensive):

• Motor-Gearbox burn-in -- 1.) Grease the gearbox. 2.) Run the motor and gearbox together for 10-20 minutes with the wheels off the ground 3.) Clean the gearbox. Do not fret over metal shavings, just clean them out 4.) Re-grease the gearbox
• Sprocket-Sprocket Alignment -- sprockets with a connection chain should be coplanar (i.e. exactly parallel and precisely transversely aligned)
• Sprocket-Wheel alignment -- The sprockets that connect to a wheel should be exactly parallel to the face of the wheel. Do not use individual plastic spacers/washers to space a sprocket off a wheel (though the solid AM spacer is fine)
• Bearing-Wheel alignment -- When wheel (without connecting chain) is free-spun on the axle that connects it to the frame, there should be NO wobble on the wheel structure (tread wobble is fine for the most part).
• Chain Tension -- Use at least 120-degrees of chain wrap around each sprocket for #25 chain or 90-degrees for #35 chain. Chain should flex roughly 3% (of the sprocket-sprocket distance) up/down -- i.e. it shouldn't be so rigid that there's no vertical flex in the chain.
• Do not settle for the KOP gear ratios if those ratios don't satisfy how your team wants to play the game. With a stock KOP drive train, the easiest/cheapest way to adjust gear ratio is to change the sprocket located on the gearbox output shaft.

I'm sure there are other tips that I'm forgetting at the moment.