Pneumatic gurus

[iOnic]

I've had a little idea in mind for a while and it's kicking up a notch. I have 4 air cylinders I would like to automate. They are 2 port push/pull Bimba stainless items.

I would like my ECU to push a pair of them at a preset point and pull them at another preset value.

The other two I would like to push via a push button type switch ie: when switch is held down, air is supplied to push ports and when button is let go, air is released from push side and applied on pull side.

I have all the gear I need and setting up the ECU is a walk in the park. What i'm stuck on is the link from electronics to pneumatics.

I'm no expert so am unsure of what valves, switches, solenoids I will need. This is all 12v by the way. I know there are many here smarter than I so your advice is appreciated.

[Grrrrrrr!]

You need 5/2 12v solenoid/spring valves. Size depends on air cylinder sizes and how fast you need them to move. 5/2 = 5 port 2 position

[iOnic]

These are the air cylinders. Tried to give an idea of size in pic but they're (estimates) about 280mm long and about 30mm OD with a 150mm-ish stroke. Got a spec sheet for them somewhere but my desk is a mess Not really fussed about speed at this stage.



So if I understand you correctly, you're saying to get 2x 5/2 valves each with 2 cylinders connected to it and the 5th port for air supply? Sorry bit of a noob here

[Grrrrrrr!]

2 x 5/2 valves, each has 5 ports (2 to the cylinder, 1 supply, 2 exhaust)

actually, you could use 4/2s if they are cheaper. you can pair the cylinders up off one valve, but if you need them to extend/retract at exactly the same rate you need to do this mechanically.

If you need an "OFF" state where there is no pressure applied to the cylinder you need 5/3 valves.

http://gearseds.com/curriculum/learn/lesson_print.php?id=86
look at figure 2.74 and 2.76

[QikStarlie]

tell me you're building some kind of variable intake system.

[MAGN1T]

Go to pick a part, look for a 3 port solenoid, same as what some mitsis use on the fuel system for the hot start.
Then all you need is to hook up 1 port to a vac source, 1 to a pressure source and the common one to the cylinder. You can use more than one solenoid of course.The size of the valve determines how fast the thing operates.
For a vac source, you'll find vac reservoirs there, one way valves too, common on some diesels.
You could get away with just vac and a return spring.
Another way would be to have vac on the common and the other 2 ports of the valve going to opposite ends of the cylinder(one clyinder end would need to be vented though with another 3 port valve). There's plenty of ways to do it.
Carbied corollas are really good(late 80s, early 90s), they've got a carbon canister and a really big solenoid valve on that, only 2 way though.

Steve

[tim_blair]

is there any reason you want to use pneumatic actuators rather than electric?

[Grrrrrrr!]

If you are using manifold vacuum or boost you will get bugger all force out of them, ~3kgs of push at best at 8psi, and slightly less on retraction. These things are designed for 6-10bar normally.

[iOnic]

Nah not using boost. Got onboard air compressors etc. Chose pneumatic because I already have 95% of the gear I need. Not taking second hand bits off other cars if I can help it

[tim_blair]

what is the project that you want to do?

electric would be waaaay easier

[Dell'Orto]

fuly bagd 0t corolla bei?

[Grrrrrrr!]

Active aero on a cynos?

[gt4dude]

up 2 broooooooo

[gt4dude]

i can tell alot about u by what i can see on your table, i think we'd get along eh lol

but seriously, what are you making?

[iOnic]

i can tell alot about u by what i can see on your table, i think we'd get along eh lol

You're a messy bastard too?

Purely out of curiosity, what does my desk say about me?

[Boosted_162]

i can tell alot about u by what i can see on your table, i think we'd get along eh lol

You're a messy bastard too?

Purely out of curiosity, what does my desk say about me?

Your messy and like cars.

Correct?

[Elmendorf]

i can tell alot about u by what i can see on your table, i think we'd get along eh lol

You're a messy bastard too?

Purely out of curiosity, what does my desk say about me?

Your messy and like cars.

Correct?

There's computer crap on there too (and I don't just mean his computer).....

[Bling]

You like to sit in the warm, log burner RIGHT next to pc You also like to smoke sticks of memory. Can't figure out the mac stuff on the hp though.

[gt4dude]

the one thing i dont understand is the lighter and the cityfitness book

[iOnic]

haha I don't smoke. Lighter was brought in when I was building an ECU and had to heat up shrink wrap. Hasn't left since Log burner doesn't go but when it did...I was indeed very warm. Sticks of memory are from when I last took my (other) computer apart. Mac stuff is because my current computer is a Mac - just using the mouse and keyboard off my other computer (not an HP....). Not actually sure where the mouse and keboard came from...never owned an HP. They must have appeared one day and decided never to leave. Cityfitness is a gym, I go to it - that's my membership info in the booklet.

Who'd have thought you lot could tell so much from some junk