Slickest drive transmission yet...

[dlavery]

Originally Posted by phrontist

I wonder how they could be topped...

(A CVT perhaps? )

I loved the CVT designs that have popped up a few times in recent years. But with ones like the ThunderChickens design, we could only look on with envy and the realization that it was a design we could not build without a much better fabrication capability. That is why the Killer Bees design is so brilliant - they get a similar level of performance (particularly with the automatic shifting function), but you don't need any high-end tooling to put it together. Just about anyone with access to a moderate high school shop can build it. In that respect, it is a truly elegant design.

-dave

[Elgin Clock]

Speaking of Drive systems.

I would like to thank Dave Lavery and the crew at Team 116 for the awesome shift on the fly gearbox they shared with the FIRST community.

We used that this year, and so far have been unstoppable to get our bot up on that platforms! (Both of them)

We modified it a tiny bit, and included a little extra spiffy design work in the end plates and the gears.

Thank you Team 116, and be sure to stop by our pits in Atlanta to see what kind of full drive system we came up with including your gear box!

[ngreen]

Thanks for mentioning this. I can't wait to see a whitepaper. I've started to look for a new drive system for next year and something like this sounds great. We don't have the best machining ability so something that can't be done in a high school shop would be great for every team. Since next year will be our third year it would be nice to make a transition from a single speed chain drive system to a multi-speed transmission. I will have to look into this.

[Salik Syed]

actually our team(701) built a CVT transmission much like thunderchickens without that much machining capabilities UC davis did housing plates BUT it wouldn't have been hard to do it w/ out mill but when the mill came we didn't know how to use it ...lol (it came like 1 week into the competition)

[Cory]

If I remember correctly, your system only gave you a constant torque at all speeds, rather than the Thunderchickens, which gives them variable torque at different speeds. (It's still a very cool pseudo-CVT, and does work well for it's intended purpose, congrats for pulling it off!)

To get back on topic, 33's drive system sure sounds amazing, and I can't wait to see pictures of it.

Cory

[dlavery]

Originally Posted by Elgin Clock

Speaking of Drive systems.

I would like to thank Dave Lavery and the crew at Team 116 for the awesome shift on the fly gearbox they shared with the FIRST community.

We used that this year, and so far have been unstoppable to get our bot up on that platforms! (Both of them)

Thank you very much for the kind words. Working with the team to design that transmission was a lot of fun, and we learned a lot! But after looking at Team 33's design, all pride of ownership in ours went right out the window! Our immediate reaction was "we GOTTA build one of those next year!"

-dave

[Raul]

I agree it is the ultimate in simplicity and function. Great job.

Enclosed is a picture of their demo board - I did not want to intrude for one of their actual gearbox.

[Jim Zondag]

Thanks, I'm glad everyone likes our design.
We have made two speed transmissions for the past several years. Each year we try to make them simpler and smaller. I found that with the kind of high/low shift range that I like to have (3:1 or more) that the robot would tend to lurch severely if you downshifted at high speeds. I really want to make a 3 speed with an intermediate gear to help this. It turned out it was easier to build a 4 speed than a 3 speed ( its really two small two-speeds in series). We focused the design around reliablity and ease of construction, the demo unit on display was made entirely by high school students in a few evenings using no special tooling.
Once I had a design with 4 gears I was pretty much forced to automate the shifting in order to keep from overloading the driver. I talked with a few Automatic Transmission experts at DaimlerChrysler on how to do a shift scheduler and viola....a fully automatic electronic robot transmission.
It really is pretty neat, providing a nearly flat power output across a very wide RPM band with a 5:1 total shift span.
I plan on posting the design and engineering here as soon as I get a good set of drawings made up (I'm not a CAD guy, I made the ones in the robot from a napkin sketch).

[Salik Syed]

This may sound wierd.......but we still haven't tested our low speed yet........haha....we will hook up the current sensors etc...AT COMPETITION!!! (funny i know) ....but they actually said their transmission doesn't give a different torque......torque remains constant....as for ours we still think it might give dif torque outputs but they say it won't..........we probably have to test it....... lol...
btw AWESOME transmission........just saw the pic

[Mike K]

I do belive that a lot of the teams that saw the 4 speed where very impressed. By the end of the day i was tired of explaning the thing.

[sanddrag]

Is there a picture of the real thing? That would serve us both better than me asking a bunch of questions. Thanks.

[Paul H]

Originally Posted by sanddrag

Is there a picture of the real thing? That would serve us both better than me asking a bunch of questions. Thanks.

Raul posted a picture.

[Chris 481]

I am from team 481 and i am tryuing to build a 3 speed
shift on the fly atomated pinion gear transmission.

My teacher saw your design and he was blown away and he wants me to build one for next year i am just looking for suggestions and a little help(pictures would be nice)
on how to build one of these transmissions.

[Paul H]

The lead engineer, Jim Zondag, is in the process of moving into a new house and is swamped at work from what I hear. I'll talk to him at the Sweet Repeat (October 9th) and see when he's planning on posting the papers.

[Kyle Love]

At Nationals my team was right next to the Killerbees, so I saw their gearbox demo thingy a lot. I think it is the coolest one I saw. Also, I just don't say that because of how it works, I say that partially because they explained to some of us how it worked etc. I wonder who will build off their design next year? Or who will go bigger and better?

-Kyle

I would also like to thank 33 for being great "pit mates".