Vex Transmission

Built this transmission. second one that I have made. with this one i wanted to make it operate like a transmission you would find in a car. it has a clutch and 3 speeds. runs and shifts great on a stand but the differential i have on the rear slips so once thats done i will post a video of it driving around or even just running on a stand. tell me what you think.

Specs- 13" Long
6" Tall
3" Wide
1st gear- 2.6:1
2nd gear- 1:1
3rd gear- 1:2.6

It looks good but It would take up a lot of space in a robot so I’m not sure of the practical uses. If you could create a smaller design then it’s potential for practical use would greatly increase.


i think that this is a really cool thing. we have been working on a transmission (for secret projects) and have thought of using pneumatics to switch the gears(this probably is not a new idea) and with that in mind would that help make it smaller for you and more practical?

I like the ingenuity of this. Nice work! Now that you’ve worked out the idea, I’m sure you could make it more compact and lay it out flat within the chassis. I’ve built a couple of 2-speed transmissions and I use a servo for shifting. Using pneumatics would add a lot of weight and take up even more room, unless you are using pneumatics anyway.

we are using pneumatics anyways so it wouldnt make much difference for us. we arent climbing either so the little more weight of another solonoid valve and more tubing from the same tanks would be insignificant. to have this be practical it would definately have to fit in the chassis though.

Yes probably. We have thought about using a pneumatic piston as a shifter also, plus I think you would only need two gear positions (speed and power).


Once you get it working well you should post a video of it in action, I’d love to show our students (plus I just want to see it running too).

I love shifters! Exploding Bacon’s VEX team had a 3 speed shifter, before FIRST moved to Tetrix.

I dont know much about it since I was not involved with the robot, However I have made a few shifters myself, and you might be able to learn some stuff with the video of our Vex 3 speed shifter

If im right the speeds were

low gear .5fps
middle gear 3fps
high gear 14 fps

There were over 60 gears on the robot! :open_mouth:

I would like to see a few more iterations try to shrink things down maybe?
Keep us updated on your progress, looking good!

just for interests sake, was the three speed transmission that you posted a link for used on your actual robot? if so what did you use it for?

another guy in our club made a transmission just like that. it works alot better and is alot faster and shifts easier but i wanted to make one resemble a cars transmission as much as possible, but mine does not work very well and is pretty hard to drive

It was used on the drive train on our Quad Quandry robot, so there were two 3 speed shifters on the bot on a tank drive system. If you have anymore questions I’ll be glad to answer (even if i was not involved with that particular robot) I have designed and built many shifters myself and would be glad to answer any questions.

  • Andrew