# Servo Pneumatics!



## Hippie Crane (Sep 17, 2019)

I wanted to show everyone this new pneumatic servoactuator I just got in the mail. How it works is you connect an air hose for the input pressure and the actuator will move to a position proportional to the electronic input signal! It has a servovalve and an LVDT inside it.

I also got a bunch of servovalve and amplifier drivers for them!


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## dflowers2 (Mar 5, 2007)

You have my interest, lol. Any chance you can post a video that can demonstrated the movement? Or maybe post a link to a video on line that shows how they work. I am not familiar with these at all. 

Thanks,
Dorian


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## Hippie Crane (Sep 17, 2019)

dflowers2 said:


> You have my interest, lol. Any chance you can post a video that can demonstrated the movement? Or maybe post a link to a video on line that shows how they work. I am not familiar with these at all.
> 
> Thanks,
> Dorian


Yes, I will post a video when I can. its essentially a valve that you can use to control the speed and direction of the air cylinder electronically. Adding a feedback loop to a PID controller allows you to use it as a servo. The servovalves are needed to accelerate and decelerate the air cylinder precisely to hit the target position without overshooting.

I'm working on a prototype for an inexpensive servovalve. Servovalves can be very pricey. The pictures above contain about $8,000 worth of servopneumatic components.


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## dflowers2 (Mar 5, 2007)

Oh, wow! That sounds very interesting AND expensive, lol.


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## Hippie Crane (Sep 17, 2019)

dflowers2 said:


> Oh, wow! That sounds very interesting AND expensive, lol.


I have a working servovalve design, perhaps once I finalize it I can create a production process and put a price tag on it. my goal for it is to be less that 100 bucks


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## Greg G (Nov 4, 2012)

Yes, price will be key.


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## pyroandy (Oct 22, 2019)

These seem to be out of the price range of most back yard haunters. I have done some things with pulsing air valves to get approximant positions of air cylinders. I can't wait to see what you come up with.


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## Hippie Crane (Sep 17, 2019)

*Desired Project Result*

Here is the desired result of my project.

I am making a replica of this blue Hippie Crane that plays the guitar.
He has to be proportionally controlled or it wouldn't look right because of the amount of degrees of freedom there are in his head, neck, body, and legs.

In this video please pay most of your attention to the blue crane playing the green guitar and watch how fluid his motions are, There is also a white crane that plays and acoustic guitar and has the exact same mech.


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## Greg G (Nov 4, 2012)

Yeah, that is really fluid. If the price of a servo valve could get down to say $40 now ...


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## Hippie Crane (Sep 17, 2019)

Greg G said:


> Yeah, that is really fluid. If the price of a servo valve could get down to say $40 now ...


I'm working on a nylon servovalve. I dont see any issue making it out of nylon if it works well. There cant be any rubbing seals so I see nylon as the best bet


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## Batbuddy (Sep 3, 2014)

Hippie Crane said:


> Here is the desired result of my project.
> 
> I am making a replica of this blue Hippie Crane that plays the guitar.
> He has to be proportionally controlled or it wouldn't look right because of the amount of degrees of freedom there are in his head, neck, body, and legs.
> ...


This is way cool that you are working on this. I wish I was able to see the original show back in the day. My Dad would always talk about the amazing animatronics that Disneyland had back then...In many ways they are more awesome than the new stuff.


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## Hippie Crane (Sep 17, 2019)

Picked up a couple of extremely rare Schenck Pegasus Model 125 "Fun Valve" Servovalves.


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## Batbuddy (Sep 3, 2014)

Sweet! good to see this coming along.


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## Daphne (Oct 18, 2006)

Sweet!! Very cool!


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