Pneumatic Autovalve - non clicking

[Carsten Svendsen]

4 valves are really hard for 1 8t gear to turn if not impossible. You'd also need a lot of pressure on a cylinder to turn them. Would you mind building a prototype of what you mean because I'm not entirely sure how it's going to work.

[Lipko]

No, because I don't have four or five valves.

[Carsten Svendsen]

1 regular sized cylinder can easily handle 4 valves as I've found out. However, where would the excess air go when the cylinder has reached maximum length?

What is so great about this original design is that there is no continuous pressure on the 8t gear at all and the fact that it can just run indefinitely.

What I came up with however is very bulky but only because I'd need to place the valves somewhere. The core idea is only 3 studs thick and could be implemented basically anywhere where it's possible to place a valve underneath it.

[Lipko]

1 regular sized cylinder can easily handle 4 valves as I've found out. However, where would the excess air go when the cylinder has reached maximum length?

Are you concerned about the stress or that the pump would continue pumping?

I'm not sure, but if you power the "pilot"-cylinder with the same pump as the work-cylinders, then switching the 4 valves would mean that the same pressure goes to the pilot- and the work-cylinders and that would immediately release the pressure from the pilot, as long as all the work-cylinders reach their end positions.

Plus it shouldn't be hard to attach the pilot-cylinder in a way, that its end positions will be the same as the end-positions of the valve lever, so the stress would be on the cylinder, not on the lever.

I hope that was clear, I'm not sure about my English at the moment...

EDIT: okay, the biggest issue with this is that probably it would be hard to set the neutral position of either valves.

Edited October 11, 2013 by Lipko

[Carsten Svendsen]

I see, that is actually very clever.

It's not what I'm looking for though as I need 4 closed loops, with 4 sets of pump/valve/cylinder to make sure all cylinders travel at the same time.

You'd also still need some kind of autovalve to turn the slave valve first though.

Neutral position doesn't matter. Who uses neutral in an automated system anyway?

EDIT: I also build my 3D model IRL. It works fine except it doesn't slide as good as I imagined since the worm gear interferes slightly with the sliding rack. It still slides to the end every time though. I'm not sure if I should replace my current autovalve with this one since it's more than twice as big, but the continuous stress on the 8t gears are much much lower.

Edited October 11, 2013 by Carsten Svendsen

[Lipko]

Yes, of course you'll need an autovalve for the pilot circuit.

For the synchronized movement/starting:

You still can have problems with a centralized power supply, if the length of the tubes to the cylinders vary.

Is it possible to include Mindstorms in your aeroplane project? It would make many things easier.

Edited October 11, 2013 by Lipko

[Carsten Svendsen]

The length of the tubes has to be somewhat the same length of course. I know that already.

And nope, no mindstorms, it weighs way too much and takes up valuable space for the big motors.

I was just looking for an autovalve solution that is fail-safe with basically no continuous wear on the components at any given time.

[Carsten Svendsen]

Jovel uploaded an LDD file: http://www.brickshelf.com/gallery/jovel/Pnuematic/auto_valve.lxf

My expectations very pretty accurate. Sliding 8t gear with a steering axle on the bottom.

[kevman]

Pvdb,

Just built your autovalve. A few questions, the mount point you show for the stationary end of the pump, did that work for you ? I had to modify mine and move it one stud down in order to get the pump to work and produce enough air pressure to move my pistons. Also, mine does click at one end, not sure if my worm gear can be mounted in such a way as to avoid the clicking. Other then that, I have it mounted in my crawler and it will power my air suspension. I love the design, it is pretty compact and doesn't require many parts which is nice.