[IDEA] Pneumatic autovalve 2

[Fistach]

Sometime ago dmac from LUGPOL published the automatic valve steered by PF medium motor. Although it was working very good it's dimensions were quite big and in the same breath - quite disappointing.

I need not 1 but 4 or 5 of these valves in my next MOC so I created the simpler and smaller version of the valve:

You can replace the red beam with something else to attach it to the frame or other structure in your MOC.

Check the video to see how it works:

With dmac valves' design the quadruple valve you can make sth like this:

Dimensions 21 x 10 x 12 (dl / szer / wys) [st] In the photo you can see that it's 22 st long but it can be easily reduced to 21 st. It's dimensions are quite big, not to mention you still have to put there pneumatic hoses and you use precious z24 gears.

On the other hand, with my design I came up with sth like this:

Dimensions are only 16x9x6 [st]

Now I only have 2 pneumatic circuits it's working very well. I tested the valve with 250 alternate switches and it was still in one piece. I'm looking forward to see it in action.

I hope it's useful for you.

[Jetro]

Looks great. I'll try and build it this afternoon if I get some time.

As for the dmac design, have you got a link where I can see it in more detail?

[Fistach]

Here is the movie:

[Milan]

This may be odd question,

Do you keep the motor powered as long as you want for a switch to stay in engaged (left or right) position?

[johanby]

What about using the x928cx1 hockey slap shot spring instead of using the axle as a torsion spring (to avoid the tension)? This has been used for example in return-to-center-steering, see e.g.

http://technicbricks.blogspot.com/2009/09/...-to-center.html

[Burf2000]

What about using the x928cx1 hockey slap shot spring instead of using the axle as a torsion spring (to avoid the tension)? This has been used for example in return-to-center-steering, see e.g.

http://technicbricks.blogspot.com/2009/09/...-to-center.html

I already done this and posted a video on youtube. Did it for someone on the forum.

However under higher pressure 20+ psi it seems to fail

I am really looking forward to building this tonight, I am amazed that this autoreturns to center. Brilliant work

[Fistach]

This may be odd question,

Do you keep the motor powered as long as you want for a switch to stay in engaged (left or right) position?

Yes. You just use the PF remote controller to do so. When you want the air going to the cylinder you just set the joystick on the pilot free. It's very similar to using LAs - it's of course less precise.

What about using the x928cx1 hockey slap shot spring instead of using the axle as a torsion spring (to avoid the tension)? This has been used for example in return-to-center-steering, see e.g.

http://technicbricks.blogspot.com/2009/09/...-to-center.html

I already done this and posted a video on youtube. Did it for someone on the forum.

However under higher pressure 20+ psi it seems to fail

I am really looking forward to building this tonight, I am amazed that this autoreturns to center. Brilliant work

I didn't have this hockey part - the advantage of my design over the hockey part is that this valve uses only regular easy to get parts (except the valves and hoses - they are not cheak but you don't need to many of them after all)

Thanks for comments.

[Burf2000]

I cant wait to try this tonight because the hockey one just does not work that well (the one I made) it seems to work for one side better than the other because you have to gear it due to lack of movement. Mine works ok but not as well as I would like. its also bulkier.

Brilliant work mate

[Zerobricks]

I like the concept, but i feel sorry for the motor...

[Milan]

I like the concept, but i feel sorry for the motor...

That is my fear, too!

Especially if some function needs for few seconds of cylinder extending (heavy lifting the boom or outriggers for example)

But cool and simple design!

Edited January 8, 2010 by Milan

[Burf2000]

I just built it and it does work really well, You do need the gap between the holding bar and the switch or else you dont get enough flex to turn on or return (well mine did not)

Anyonw got suggestions on how to make one that does not affect the motor?

Its not likely to kill the motor is it?

[Fistach]

I don't know why you think it will kill the motor? It could suffer from overheating and with new rechargeable battery it's impossible because the BB will cut the power off after too long time of heat exposure to the motor. Secondly the amount of heat generated by locked motor is so low that surrounding air will cool it easily.

[Burf2000]

Hi Mate

I was more asking the question, I cant see if causing a issue but comments above gave me the idea to ask. It works fantasically. 5 Star!

[Brickthus]

Several of the return-to-centre steering solutions presented here would apply to pneumatic valves as much as to steering.

The key with pneumatic valves is keeping the mechanism small because the space overhead quickly gets above 100% of the valve size!

For a single movement of multiple valves, consider driving a single valve and using a cylinder to drive a set of valves. A single medium cylinder can drive 4 valves quite easily in a 2x2 back to back configuration.

Mark

[Enilder]

pretty cool idea. without knowing what's going on in the motor (LEGO newb here), I am not sure if that's the safe way to go but based on what you've said, it looks good!

[Burf2000]

I just built a version of this using the old 9v motor (71427) if anyone is interested. I have a lot more of the old 9v motors than I do PF