# Servo valve...?



## Kairo (Jun 4, 2010)

Anyone know a way to manage pressure (so ...the speed) "on the fly" of pneumatic pistons ?

I saw some videos on the web about "servovlave" but i can't find a reseller for these pieces...

here some examples :






http://vimeo.com/4195913

http://vimeo.com/4195982

thx all


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## hedg12 (Jul 6, 2008)

The top vid looks like something from Einfield Technologies. The other two look DIY. Pretty cool stuff - I have some ideas for this, but no time to play .


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## Kairo (Jun 4, 2010)

yeah you're right !

i've found more informations here :

http://machinedesign.com/video/proportional-control-of-pneumatic-cylinders-0311

and here :

http://www.enfieldtech.com/video.htm

it's very impressive ...but...whithout doubt very expensive..

I also found a tiny valve from ASCO called "posiflow", it seems to work with a simply voltage variation between 0v and 24 v...am i wrong ?

http://www.ascovalve.com/Common/PDFFiles/Product/PosiflowR2.pdf


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## hedg12 (Jul 6, 2008)

I'm sure varying the voltage would work. It'd probably be easier to control with PWM - a good motor speed controller would work, assuming you could find one that would handle 24v.


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## Kairo (Jun 4, 2010)

hummm...such a valve can be very usefull..
But asco valve cost around 300$ ...
The DIY valve in acrylic glass with servo motor can do the job...maybe too slow...

However, i think the "proportional valves" are a way to explore in order to have less linear shows....


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