Slickest drive transmission yet...

BTW, Dave and the rest of the crew over on Team 116, here is our version of your designed gearbox and tranny!

Just Remember to Use Hard Metal!!!

Hardened Steel is what he means. We ground down our high gear on one gearbox in Detroit.

well our team, 1024, design a CVT VST (continious velocity, torque, variable speed transmission). it uses bevel gears and three planetary gear systems. then we ran into the problem: it was gonna weigh around 30 lbs!!! so i was told to design a casing to replace the alumnium box it was going in (around half the weighht). well we ran out of time, but i did get a nifty looking case made from a FDM prototyping machine. Hopefully (crosses fingers) we will have it done at IRI. we had two allision transmission engineers helping us design, so hopefully we can have something to show for my 10+ straight weeks of doing CAD for this. and yes i did start in the offseason…and yes it is still not done :frowning:

I was wondering if I could get some peoples opinion over weather a variable speed/torque transmission is a big advantage, or a lot of work for nothing. Our team has a CIM/Drill motor combo for our drivetrain, with no special shifting gearbox, and we seem to have pleanty of speed and torque. :slight_smile:

I’m sure it’s more complicated than I’m making it sound, but as I said, I’m stuck in the realm of theory, here.

Programming the robot to shift really shouldn’t be too complicated, with encoders measuring the speed of the output shaft or the axles. Especially since they calculated the power curves and everything. With the power curves, they can determine the best shift point to gain the most power. Finding the shift points is the hard part. Then you prgram it to shift when the encoders measure a certain speed determined by you to be your shift point. You can also calculate downshift points as well the same way.

That might be a debate for a different thread. To answer your question, though this thread from last summer contained some good debate on that topic (4 motor vs. shifters). The fourth page of replies in particular is well worth a look.

team 151’s drive this year was awesome as well… they designed the system with simplicity in mind, as well as sleek and compactness as well…
a far shot, but their tranny are smaller than the aluminum tubing
they made a new gearbox for the drills using the previous planetary gears, and made a new housing…it was gorgeous…they also implemented the pneumatic shifting, and ran the pneumatic shifter inside the drive shafts to save space…tthis thing was gorgeous… :ahh:

Apparently I got bad rep point for showing Gracious Professionalism and “hijacking this thread” to thank a team for their gearbox design we used this year.

If any one wants the name of this person who is against Gracious Professionalism and against thanking other teams, PM me.

Would it be possible to get a drawing or photo’s of this transmission. It sounds perfect. Thanks Gus

The whitepaper is coming in a month or two hopefully. It’ll include CAD drawings, instructions on construction, and a generecized(sp?) version of our automation code. All you have to do is install the sensors and download the code and your transmission will be automatic…or at least that’s the plan.

Team 33 was right across the way from our pit in Atlanta and I was over there any spare second I got to look at that demo board. When I first found out that they had constructed an automatic transmission, I freaked out. Seeing the transmission in person was something else though. Unfortunately I never got a chance to look inside their robot and see that articulated chassis that allowed them to climb the platform. I’ve been wanting to design my own drivetrain for the last year or so but with the lack of foundation knowledge and facilities it hasn’t quite happened yet. With the new robotics club I helped start at URI hopefully it won’t be long now.

I’ll be awaiting for that whitepaper with great anticipation. You were without a doubt my favorite robot this season. Good luck at any off-season comps and keep up the good work!


Hey guys, any news on that whitepaper yet?

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.

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.

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? :rolleyes: Or who will go bigger and better? :yikes:


I would also like to thank 33 for being great “pit mates”. :]

Well, I finally learned Inventor well enough to draw this transmisison up,
I will be posting this with full details in the white papers soon. here is a sneak peak.

I have posted the design for the Killer Bees’ 4 speed transmission on the White Papers board. Because the Inventor Files are so big, I could not post them all here, they are available for Download from the Killer Bees Website at

GREAT paper! Thanks for sharing.
I’m sure this will help out quite a few teams in the 2005 season.

I love the way you illustrate the power curve comparison for a 2 speed vs. 4 speed design. This is something I will show our students to help them understand these principles.

Thanks again,

If I were drooling any more, I would short out my laptop. Great work!