Pneumatic flipper with no buffer tank

[Eventorizon]

I have heard it has been done, MMM I believe. What do you have to do to get it to work? (ie, not freeze up the valves or the piston.) I know why we have buffer tanks in most machines. I am not after Explosion or Beauty levels of flip, just enough to turn someone over and lift them neatly over the wall. (Yes, its not spectacular, but it is low cost.)

Thanks :-)

[maddox10]

FP without buffertank is old school. Use fire extinguisher valves. No freezing problem.

[Eventorizon]

Literally... Main Tank - Valve - Spring Return Cylinder - QEV?

What are the main draw back to this kind of system?

[Max]

No point in having a QEV, your flow is greatly restricted already by not having a buffer tank as the valve on your main tank will have a very small orifice and you've got to wait for the co2 to boil which will further restrict flow.
This will mean your ram will be quite slow so as you say it won't be very impressive, but with good design it could turn someone over or possibly throw them over the side.
Although personally I'd just use a buffer tank, there not really very expensive it's just a small powder fire extinguisher from the scrapheap then just a pneumatic adapter.

[maddox10]

Max, I think Event Horizon ment FP, to simplify the setup as much as possible.
A simple setup I imagine is

Paintball tank feeding to a fire extinguisher valve/handle, a strong servo with a cam can open that, en then straight to the ram. The single acting ram can be pulled back with a bungee, and the exhausting done with a 1.5mm hole in the bottom.

Oh, Chaos 2 used the fire-extinguisher trick. Neither slow nor powerless...

[Eventorizon]

Maddox is right, I am trying to simplify the system as much as possible. A spring/bungee return weapon with a single main tank. Its not even to do do with cost, you can pick up a 12oz painball tank for £20.

And I remember Chaos 2 ran a fire extinguisher! The definition of power!

[Liftoff]

Would a full bore ball-valve of the correct pressure rating do instead of an extinguisher valve? You could easily fit a servo motor to the valve spindle and operate it remotely...Think it will be much more efficient as its not restricted.

[maddox10]

A poppet valve has advantages to a ball valve. But the idea is the same. Using an RC controlled servo/motor to open a valve.

[webby]

Just got an extinguisher today, has anyone done this before? any internal photos of chaos 2?

[leorcc]

It is pretty simple, but you will need a beefy servo to accomplish this. A standard 4kg/cm S3003 will not cut it.

[webby]

ok cool, I might just use a 1/5 scale servo? and what sort of Kg torque would you recommend?

[maddox10]

I had good results with a Hitec 805, that's a 1/4th scale 19kg/cm servo. But that was ages ago.

[webby]

Ok ill have a look, do you have any photos of your setup?

[maddox10]

I'll have a look in my archives. But I doubt I have a picture of that. Was an experiment before I learned about the Burkert 5405.

[maddox10]

Don't have a picture of that setup. But in a search for "stuff", I found a fire extinguisher valve.
Will make a setup based on this thread.