Universal/Standard Drive Base

[jamie_1930]

Soon team 2228 will be undertaking the task of reviewing all current drive bases to see the pros and cons of each and in the end come up with "the perfect" drive base so that we can speed up the design process of future years by having a pre-agreed upon drive base, that we feel can accomplish what we'll need for in any FIRST game. My question to everyone is are any other teams doing, thinking of doing or have done this in the past? If so do you have any advice on the matter? And also what is your opinion on whether this is a good move or not?

[CENTURION]

Personally, I don't really think that it is possible...

For instance (even though this was my first year in FRC), I know that many of the drivetrains we saw used in Breakaway would not be a good fit for lunacy, and vice versa.

Specifically, lets look at swerve drive. All the pictures I've seen of swerve drive from games that are not Breakaway, have very low ground clearance, like 221's drive (not sure what year this was though):


If a team wanted to use that in Breakaway, they would need to use the tunnels, but a drive like that also doesn't leave a lot of room for a kicker, or lifting mechanism. Thus, you make the robot bigger, which means it has to go over the bumps. But that frame won't let you go over the bumps, so you have to raise your ground clearance, a la team 2108:

Originally Posted by jamie_1930

Soon team 2228 will be undertaking the task of reviewing all current drive bases to see the pros and cons of each and in the end come up with "the perfect" drive base so that we can speed up the design process of future years by having a pre-agreed upon drive base, that we feel can accomplish what we'll need for in any FIRST game. My question to everyone is are any other teams doing, thinking of doing or have done this in the past? If so do you have any advice on the matter? And also what is your opinion on whether this is a good move or not?

If you'll use the handy-dandy search feature, you'll see that it's been tried, and fallen flat each time.

That being said, let me know if you make any real progress and I'll jump on board.

[kevinhorn]

Please keep in mind that you will have to post your design on a CD like forum in order to use any design created outside of the build season. Good luck I look forward to considering your new design for our teams robot this coming season.

[MrForbes]

Since each game is different, the robot to play each game has to meet different requirements, so it's not real likely that there is such a thing as a universal drive base. If there were, it would probably not be optimized for any game.

How about coming up with half a dozen designs that are not quite finished, but can accommodate different game requirements? You can use past games for ideas for this. Of course, the real game next year will not be satisfied by any designs you come up with before then...says Mr. Murphy

[Chris is me]

Originally Posted by kevinhorn

Please keep in mind that you will have to post your design on a CD like forum in order to use any design created outside of the build season. Good luck I look forward to considering your new design for our teams robot this coming season.

Is this true? I've seen multiple designs based on concepts thought of during the off season this year that weren't posted on CD.

[Radical Pi]

Originally Posted by Chris is me

Is this true? I've seen multiple designs based on concepts thought of during the off season this year that weren't posted on CD.

If parts are specifically designed during the off season it has to be posted. Concepts/unfinished parts are legal to keep to yourself if you modify them during the build season

[Daniel_LaFleur]

Originally Posted by Chris is me

Is this true? I've seen multiple designs based on concepts thought of during the off season this year that weren't posted on CD.

Originally Posted by 2010 rules

<R25> Prior to the Kick-off: Before the formal start of the Robot Build Season, teams are encouraged to think as much as they please about their ROBOTS. They may develop prototypes, create proof-of-concept models, and conduct design exercises. Teams may gather all the raw stock materials and COTS COMPONENTS they want. But absolutely no final design, fabrication, or assembly of any elements intended for the final ROBOT is permitted prior to the Kick-off presentation.
*Example: The same TEAM realizes that the transmission designed and built in the fall perfectly fits their need for a transmission to drive the ROBOT arm. They build an exact copy of the transmission from the original design plans, and bolt it to the ROBOT. This would be prohibited, as the transmission – although fabricated during the competition season – was built from detailed designs developed prior to kick-off.
*Example: A different team develops a similar solution during the fall, and plans to use the developed software on their competition ROBOT. After completing the software, they post it in a generally accessible public forum and make the code available to all teams. Because they have made their software generally available, under the terms of Rule <R67> it is considered COTS software and they can use it on their ROBOT.

<R34> Parts custom-made for FIRST and provided to FRC teams in the Kit Of Parts for previous FRC competitions (e.g. 2006 FRC transmissions, custom-made motor couplers, custom sensor strips, FRC CMUcam II modules, etc.) may be used if the part is still functionally equivalent to the original condition and:
A. The part is now generally available as a COTS item from an accessible source, or
B. All information required to fabricate the part (e.g. complete drawings, materials list, Gerber Files where appropriate, etc.) is openly available, such that any team could fabricate the part (or have it fabricated for them).
Otherwise, such parts are prohibited from use in the 2010 competition.

Emphisis mine.

Also, be aware that the rules may change for next year ... but as of right now, no final designs can be created prior to kickoff.

[ajlapp]

Team RUSH (frc27) has used the same universal chassis concept since 2008.

The team has agreed that in order to work as efficiently as possible we will use the same standard chassis design and adapt the rest of the robot to work around it.

In my opinion, many of the most successful teams deploy similar strategies....though I don't know if they actually have an edict stating that they won't bother reviewing other ways to design or build their chassis like we do.

Our base chassis is a simple 6wd. It has no features or options other than wheel size and transmission style.

[Jon Stratis]

The idea of having a "standard" drive train you use year after year does have its benefits - you already have a rolling practice robot on day 1, you can get any needed parts for the drive train early and get a basic robot built quickly to start adding manipulators, and everyone knows exactly how it works.

But it also has some con's. As others have said, it probably won't be the "best" drive train for any given year - jack of all trades, master of none. But there's another huge con that you'll be depriving yourselves and future students of: The ability to design, build, and test a new drive train every year. Where's the fun in building the same thing every year? How much do you learn the third time you've built the same drive train?

We go in every year knowing the options for a drive train: 4 wheel, 6 wheel, omni, mecanum, crab, casters and traction wheels, something crazy. Over the past 4 years, we've done 6 wheel's twice, 4 wheels once, and mecanum once. And every year we have a valuable discussion with the students about what drive system to use, what the pro's and cons are, etc. Then the students get to work out the specifics of the design and build it. Yeah, it may take a little longer... but it's a valuable process.

[ttldomination]

I think that the teams who use the 6WD found it relatively easy to carry their dropped centers into the 8WD scheme. I think it's definitely possible to create a very *basic* layout, but don't let that stymie you from any possibilities in the build season.

- Sunny

[sdcantrell56]

We have pretty much used the same design the past 2 seasons albeit with improvements on manufacturability and maintenance each year and really even the 2 seasons before; however with different materials. It is awfully hard to argue against a well designed 6/8wd drivetrain particularly when taking into account time to manufacture/design/program. I am a firm believer in sticking with the basic skid steer drivetrain unless there is some never before seen drastic change next year.

THere is a lot to be said for having a general idea of the drive walking into the season and just being able to churn one out in the first week or so and devote all of your time towards perfecting a manipulator.

[Dennis Jenks]

Originally Posted by CraigHickman

If you'll use the handy-dandy search feature, you'll see that it's been tried, and fallen flat each time.

I don't know about that..........some would say that 254 has done ok since standardizing their drivetrain in 2004.

[Josh Fox]

Originally Posted by Dennis Jenks

I don't know about that..........some would say that 254 has done ok since standardizing their drivetrain in 2004.

I, and anyone who knows anything about the Cheesy Poofs, would have to agree with this. While this year they may have had 8 wheels instead of the usual 6 typical of the "West-Coast Drive," there's nothing radically different from year to year from what I have seen.

While the chassis doesn't necessarily make or break a robot, I think there's something to be said about using a somewhat simpler design that's perhaps weaker in comparison to other designs, and instead using those resources, i.e. manpower and time, to focus on other challenges.

[Andrew Schreiber]

Originally Posted by Josh Fox

While the chassis doesn't necessarily make or break a robot, I think there's something to be said about using a somewhat simpler design that's perhaps weaker in comparison to other designs, and instead using those resources, i.e. manpower and time, to focus on other challenges.

<threadjack>
I agree with your final conclusion that time can be spent elsewhere but NOT on the reasoning. A good drive train is critical to having a successful season. It will make or break your season.
</threadjack>

When doing your research for this SDB please consider multiple options rather than just copying 254. For example, weight the benefits and costs of sheet metal, fiberglass, wood, steel, welded tube, etc. Weight the benefits and costs of cantilevered wheels. Shifting vs One Speed. 6wd, 8wd, 10wd, 14wd. Also, share your research. Publish a white paper on why you chose one method over the other.