Hey ppl, just joined the formula racing team at our uni and my team's working on designing a paddle shift for the gearbox. I've been looking at various options and it looks like we're gonna go with a pneumatic system.

I'm just wondering what kind of air sources are normally used? i've been looking for some 12v compressors, but i have no idea what kind of size i should be looking at. Also what kind of storage tanks are people using?

I'd start by looking at some commercially available systems

CO2, Air, Nitrogen, etc. We have a large cylinder that we bring with us to test the car.

Fortunately when the cops came (from our car setting off an alarm in a nearby building), they didn't ask how a high pressure steel tank sitting on a hand truck next to my F150 had gotten there... They were too distracted by the eardrum blowing RPI intake...

Anyway, hope that helps somewhat.

quote:

Originally posted by duckei:
CO2, Air, Nitrogen, etc. We have a large cylinder that we bring with us to test the car.

Fortunately when the cops came (from our car setting off an alarm in a nearby building), they didn't ask how a high pressure steel tank sitting on a hand truck next to my F150 had gotten there... They were too distracted by the eardrum blowing RPI intake...

Anyway, hope that helps somewhat.

So the car ran with enough gas supply in the tank to last the entire race, ditching an onboard compressor? That sounds like a good idea actually, not having to zap any power from the car

Its really easier than it sounds. Grab yourself some paintball and industrial pneumatics components and rig something up. Beware not all gasses are created equal.

We have previously used a paintball gas canister for our airsupply. There is a few previous posts about this topic as well and they have the websites listed where you can get the parts.
We are in the process of switching from paddleshift to plain electric, the whole shifter unit works out to be lighter then our airbottle and just gets rid of an extra system, reducing complexity IMHO. Pingle make a shifter designed for use with a motorcycle gearbox, but their offical line is that they wont sell it by its self you have to buy it by its self. Just say you already have their system and your shifter broke and they will send you one for about $350 USD, hook it up with a couple of MOSFETS and you have a nice little system.

It's advantageous to use a liquid gas source (e.g. CO2 sodamax or paintball bottle), just be aware that the gas cools down during expansion, which can make your tubes brittle. There's no need to create pressure by a pump in the car, our CO2 supply lasted for several endurances.

As for components, industrial stuff like festo components works just fine, but you'll need someone who can design the controller.

Also check the other threads on the shifting topic in this forum, getting it reliable is much harder than it seems on the first look. We've killed at least one gearbox during last years tuning process.