Crazy Drive Train Ideas

A few members of our team are working on crazy drive train ideas. While we have plenty to work with currently, I hope to get through them and onto more. If you have any weird drive train ideas please post them here and do your best to describe them. I don’t want anything that’s already been seen around such as nona-drive and kiwi, I want brand new ideas. We plan to CAD and build all these drive trains using the kit of parts c-channel this summer. Please post any ideas, thanks.


One large ball with a traction wheeled motor rolling said ball in the y direction, and another in the x. I can’t see this ever being practical, but it would be fun to build and program.

I have a really crazy drivetrain idea. Instead of 4 wheels, put 6 wheels on a robot, and make the center one lower! That way, robots will have a shorter wheelbase for turning but high traction all around! :rolleyes:

Of course I’m kidding, but I’ve always wondered why people take the “let’s do something weird for the sake of it” approach to prototyping, rather than engineering a drivetrain that tackles a design aspect differently. I think you should totally build a crazy drivetran, don’t get me wrong - but maybe it would be a better exercise to figure out what current drivetrains you use don’t do very well, and then figuring out a new drivetrain optimized toward different design criteria than the bog standard.

The latest innovative drivetrain in FIRST (nonadrive) probably wasn’t thought of by going “hey dude, what if we did THAT?”. I imagine they specifically looked at a way to accomplish something not present in a 6wd (strafing) without some of the drawbacks of drivetrains designed for that (swerve, mecanum). Maybe you can do the same thing - and come up with something incredibly crazy, but useful too!

Well, since Winnovation stole an idea I had in 2007 of 6 wheel crab drive I guess 8 wheel crab drive is the next new thing of the future! :smiley:

I don’t know, but that sounds perfectly plausible to me. Some of the best ideas on my team have come from people just talking about hypothetical ideas or things that would be cool, and then someone sees the implementation in their head, and it just takes off.

  • Sunny

i think it would be cool to see a crab-drive tankdrive robot :ahh:

Here is a link to the ball drive Team 45 came up with back in 2003. Also, search for ball drive under CD-Media to see more pictures.

Team 179 and 1345 collaborated in 2009 and built a crab drive. The crab drive also drove like a tank drive. Is this what you meant?

I believe team 2342 Team Pheonix from Nashua/Merrimack New Hampshire did a design in 2009. It was a standard crab drive robot but with added code allowing to act as a crab, tank, and ackerman steering and even some slight combined variations.

Is that sort of what you were thinking of?

Tons of crab drives do that. Not to take anything away from the 5 or 6 teams each year that tell me their drivetrain is a crab drive AND a tank drive, but that’s pretty standard.

I think he meant swerving tank treads or something.

Yah I was confused as well thinking of the same thing, “aren’t all crabs tank drives?”

I think it is just one of many things that makes me crack up back on pit scouting or alliance strategy. “Our robot has a very low center of gravity!” That is great, but how does that large heavy steel arm play into that?

4 wheel crab with actuator legs (

lets make the legs 3-position pneumatics.

and while we’re at it, figure out some way to mount the bumper is its '10 legal.

or the beautiful rotating mecanums would be nice
i have a design that could be driven by one set of motors and still be holonomic


i would actually like to see a robot with a bike drive train, even the most basic bicycles have at least a couple different gear ratios, and there are some bikes with upwards of 24.

I think I have exactly what you are thinking of this was one of our programmer’s, dana, idea in 2009. He called it serpentine drive and was designed to slide across the regolith, similarly to a snake. I hope I can explain this well enough for some people to get, and I’ll try and follow it up with some of dana’s prototyping of the drivetrain. You make multiple wheel assemblies that would include two wheels, parallel to one another and unpowered, with a center pivot in the middle of the two. Now you would have the center pivot offset from the center of a gear, then put a series of this in a line with eachother, connected with springs to the front and back of each and idler gears inbetween to maintain direction. Each of the assemblies would then be offset slightly so that when the whole thing was powered by a single motor the wheel assemblies would travel in a wave.

i just came up with another one, make a robot that is entirely encased in a hollow sphere with omni wheels on every corner facing outward, to drive the main part of the robot drives the inside of the sphere, if we ever get a water competition this would be highly helpful i think.

The Idea has been lurking around in my head for longer than that, Dillon just made it feasible by making tiny modules :wink:

You have to be careful that you think about this in the right way. There have been all sorts of crazy drive trains in FIRST. Ball drives. All sorts of swerves. Active and passive suspensions (especially this year). Walking file cards. Ball differentials. CVTs. 2 speed (AM-style), 3 speed (DeWalt + 222 ball lock shifter), 4 speed transmissions (33). Brakes. Triwheels. Traction wheels, inflatable wheels, omni wheels, mecanum wheels, treads. Nonadrive. The list grows every year.

Some of the above have been used to great effect on certain robots. Others tend not to do as well. What’s the difference?

The teams that succeed on the field don’t generally seek to innovate their drive systems for innovation’s sake - they instead analyze the game and what they want their robot to do well and use that analysis to drive their choice of drive system. In other words, before trying to think of off the wall ideas, think of what possible situations would cause the “tried and true” FIRST drive trains to fall short.

Steps? Driving on sand? The return of regolith? What if you decide you need holonomic/swerve-like agility with extreme pushing power (especially if you decide that your team isn’t a good fit for swerve, either financially or because of fabrication resources)? How can you ensure that nobody can cause your robot to turn if you don’t want it to?

(I’m speaking about drive systems you would actually want to use on a competition robot here. In the offseason, or for demo purposes, sure, anything goes. But the teams that succeed on the field more often than not have competition on their minds before they go and prototype.)

While I know that this is not the best idea as far as making a game applicable off season part, with summer coming and the GDC refusing to give me a game hint to work with, I am bored and need something to do. Please do not criticize what we are doing and keep the post to drive train ideas and discussion.

To sum up the critics of this thread:
“An innovation needs to be set to a strategy, solve a specific problem and be practical before the design even starts.”

Thank God DaVinci didn’t think that way, nor did these guys
The methodology of complex innovation has been around since the Rennaisance Era, and didn’t start with a specific problem to solve. The problems are abstract, even in the FRC Drive Train realm: design a drive train that is both agile and has high tractive power. The reality is that solving the problem is an excellent lesson in Innovation itself and the lessons learned will carry further than just the FRC season. The biggest lesson is that there is never a silver bullet to solve every problem in a mechanical system. Given that now is the Prototyping Season, this is a fun discussion with perfect timing.

I don’t understand why all teams want the drive train to do everything for mobility. If the rules allow for it, why has no one even prototyped something like a tethered Quad Rotor that lifts off and gets the game object? Sure, the thing would probably get beat up during a finals match but the sheer success in prototype will spur a LOT of creative thought come build season. Of course just implementing a quad rotor with limited amounts of motors is a feat and requires its own innovations worthy of patents and PHD’s, heh. Then there’s the control component, which many programmers would salivate at the chance to do, and the sensor feedback component which boggles the mind of even the smartest professionals.


I’m sorry if I came off as criticizing - I think that no matter what you decide to do, prototyping in the off season is very beneficial and a lot of fun! True innovation doesn’t necessarily require a concrete problem first, but history shows that necessity is the mother of invention quite often.

I was just throwing out that if you want to prototype for fun and to for practice, why not also practice analyzing a FIRST-like game challenge. While the GDC hasn’t given hints towards 2011 yet (and given past history, they are unlikely to do so until much closer to kickoff), history shows that elements of past games tend to be re-used in new and slightly different ways. Pick a game that you aren’t familiar with, analyze some of the technical challenges, and think of ways to solve them.

Either way, you’ll have fun and learn a lot.

An idea need not solve a specific problem but a design should. That problem can be completely off the wall or it can be realistic. A water game, not so realistic for FRC but figuring out how to navigate under water would be useful for NURC.

I suppose there are two ways of looking at this, either you can define a problem and develop a solution or you could define a solution and develop a problem. Personally, I prefer knowing my problem first as it means I can more easily break it down into sub problems to be solved.

As for crazy drive trains, why not do a definitive test 14 wheel drive (703) compared to 6wd or 8wd or 2wd? It might be that having more wheels has benefits that we can’t see easily.

As far as problems you might want to look into solving I would suggest climbing stairs (6" or more) or navigating on a narrow area (see 2004 field centerpiece for example). These are challenges a lot of FRC teams have never faced and none of the students still on teams have faced.