pic: 6 speed?? Great in theory - lets see how it works!

[Manoel]

Originally Posted by dez250

The only way i have seemed to get a pneumatic piston, like those in the kit that only have 2 ports to move to more then 2 positions well requires multiple pistons. Take 3 pistons, and put them in series (like one after the other). So when you have the all retracted its on the first length, piston a extended and piston b and c not extended is length 2, piston a and b extended with piston c not extended is length 3, having a not extended with b and c extended is length 4, having a and c extended with b not extended is length 5 and having all a b and c extended is length 6. Its actually works really well you just have to tweak it before it goes on the bot. So like resistors in series, you can get pistons in series in a way to act together like a single piston with multiple positions...

Hope that helped..

Except resistors are tiny and pistons are not
You are talking about fitting 5 or 6 pistons in a gearbox that's supposed to be a few inches thick...

I would go with a lead screw with a huge pitch, so that rotating it a few degrees would make the shifter move a considerable amount. Depending on the forces involved, a servo could be used to precisely turn the lead screw, sliding the shifter and making an accurate change of gears.

BTW, your design looks very good

PS: It's pretty late and I'm an Electrical Engineering student, so bear with me for any major mechanical inconsistency in this post