Smallest VEX with Transmission!! 2 speed!!!

i have created a vex bot that has a 2-speed transmission that is built right in. i believe it is the smallest yet! :smiley: :smiley:

here are links:

if there is a smaller shiftable bot, let me know!](

so far i’d have to say yes and it has good steering
but how did you make the bar for the front

What the small c-channel? You can get it in the advanced metal kit.

Lokks pretty nice. Someone ought to try to make a 5 speed VEX transmission.

Indeed it does look small. How well does it work? Can is shift on the fly?

i think vex has a linit on how small it is possible to make a transmissio. yours is quite small, but the 84 tooth gears make it the first with them i’ve seen

the bar in the front is just 2 side pieces bolted together, i’ll get a closeup

yes, it can shift on the fly, and the top speed is perfect (real fast)

i am glad to get some recognition for this. it took 4-6 hours just to get the gears right for the small size

i think one of the lesser points of your robot is that it is just shifting on one side, which doesnt make sense to me. each tiime you shift, the robot is going to have to force two sets of gears to mesh. it would make sense if both sides were powered by an individual motor, but you have it needing only a common shaft connecting the rear wheels since they cant possibly turn differently. otherwise, i like the shifting mechanism.:slight_smile:

thanks, it feels good to be recognised. about its flaws, pacoliketaco, it needs improved, and i need parts. what can i do:)

Nice. I like the way you move the intermediate axle with a slider between collars.

What if the motor and driving gear stack were mounted on a plate that slides on a pair of axles as sliders?

i know what you mean…

Here are your pictures:


BTW - Is it programmed? If so, what does it do?

no, it is not programmed, i used the remote to control everything, it fell apart often, which is the only bad part!

if it falls apart often how useful does that make it??

If it falls apart alot, try building a stronger chassis around it if you have the parts.

if there is a smaller shiftable bot, let me know!](

That is a “clever solution”!!!

Which parts “fall apart”??

How does it turn without a differential? I’m guessing the back two wheels skid when your robot turns, since both back wheels are going the same speed?

The way i’m trying to approach it is to make a small gear box (I have made it but i had to take it apart) and then attach the output gear of it to a differential that is attached to the back two wheels, and a motor to the input gear of the gearbox. That way, you wouldn’t have to go through the trouble of lifting your robot upside down every time you want to work on the gears.

But I’m also thinking how the shifting would work. I remember one team used a very complex shiftable gear ratio for their robot.

anyways, nice work.