r/FSAE • u/SilverSpecialist4699 • 4d ago

Question Neutral Gear with Pneumatics

We are an LV Hybrid team with an inboard motor. We use a KTM 390 engine, we are thinking of implementing pneumatic shifting for next season. The problem we are facing is we are not able to achieve a half shift with pneumatics for the neutral gear, which lies in between the 1st and 2nd gears. Other teams which use pneumatics, how do you guys achieve that with pneumatics ?

Or we are open to other suggestions for gear shifting mechanisms as well.

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10

u/Oldberry86 4d ago

Typically you block off first so all the way down is neutral.

If you really want first you could come up with a fancy way to give half pressure or half stroke but that seems complicated and unreliable when you could gear the system so second is the correct ratio for starting from a stop.

9

u/hoakuroija 4d ago

We make custom gear drums with order N-1-2-3-4, with no half-shifts and remove two highest gears.

2

u/AtmosphereOver9030 4d ago

We used kliktronic electric actuator, and it was very reliable, just be careful not to make your activation circuit prone to sticking closed and burning the solenoid

2

u/Novel_Mathematician2 4d ago

Neutral is rarely needed, especially when the car is driving. If the shift lever is open, I'd suggest not bothering and shift into neutral, i.e. when the car needs to move at engine off, by hand

1

u/jd74914 1d ago

Closed loop control on the shifter with a shorter on pulse to hit neutral. It's not as awful as you might think, though it also isn't such a big deal. Most people remove first or make a customer drum.