Thread: Elevator Help pneumatics??

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OK,

I have most of the parts lying around and have eyed up a steel base that is free.
I can do the controller and what not.

My problem:

I want different speeds of jarring motion. If I use pneumatics when triggered the clyinders will see the same PSI all the time. I can make the cylinder move up/down/stop/ HOW do I do a big jolt and a slow ascent/descent??? A solenoid will only turn on the cylinder it can't controll the speed at which the cylinder moves, this is done with flow controlls but they are set and remain constant. Some I might want fast IE hitting bottom, others slow IE the moving down and pressurizing back up while guests are in the eleveator

Any thoughts or am I over engineering, again
-PB

any websites, not much in the "haunted elevator halloween prop" google search
been to garage of terror and the hellevator not much help

Oh, are you doing an elevator too? We've had our base ready for a couple of months. Just waiting for warmer weather to go further with it.
Can't wait to see what you do with yours

MsM

I think what your looking for is a system that uses a proportional servo pneumatic valve and a cylinder with postion feed back. The issue here is cost there not cheap. Here is one company
Proportional Control of Pneumatic Cylinders | Machine Design

Fright Props uses air bags to lift their elevator platform. Perhaps you can look at how they do their system for some ideas: FrightProps - Halloween Decorations, Halloween Props, Pneumatic Props, Animated Props, Halloween Accessories

Here's what they use the air bags for: FrightProps - Halloween Decorations, Halloween Props, Pneumatic Props, Animated Props, Halloween Accessories

OK....but....how do they make the bags work. Didn't find any detailed info there. How do you make a jarring or sudden stop. Would seem to bounce but I"m just guessing

I just got a new customer this week and would you believe it. They make air beds and air beds use big bladders with pumps .... SCORE ... I am gonna be their new best friend in the months to come. We'll see how or if I can apply thig technology.

Back to the pneumatic aspect. Proportioning valves huh I'm researching this now. Found some used not to bad price under $100 but not sure what kind, and application. Don't have enough knowledge on these, looks like I'll keep reading.

But this proportioning valve may be the answer. If anyone has used these please let me know, I have some quesitons and will have more

I was suprised not many of these have been built or am I just missing the links??

-PB

WOW

YouTube - Control of Inverted Pendulum with Servo Pneumatics

No clue how or if I could use any of this technology, I am assured WAY out of my price point and knowledge zone.

BUT

Has the features of fast/slow/jarring I'm looking for

-PB

I found this from a vendor:



I might start looking into it. I need to price out bags, I am considering machining my own air bags....we'll see

-PB

I am guessing that you would control the left/right with a VSA program. You would also have two solenoids set for movement (Left:up/down and right:up/down) and the two solenoids are separately controlled by the VSA program. In that diagram you have I would think you would only have the control of up/down.

For controlling speeds of pneumatic cylinders or bags you should use flow controls. They are adjustable so you can set your rates separately. They are basically needle valves and a check valve in parallel. So when air flows in one direction it free flows through the check valve, but in the other direction it has to flow through the needle valve controlling the air flow. These do not effect pressure at all just speed. They are also relatively cheap.

With a proportioning valve it is best, if not necessary, to have feedback to control it. So that means you'll need to have a pressure sensor as well as the proportioning valve. Both of these are analog signals which you need to monitor and control. You could use a PLC to do this type of control but it's going to get kind of expensive.

I think your best bet is to go with the flow controls and maybe use a pancake cylinder of some type.

Originally Posted by Terra

I am guessing that you would control the left/right with a VSA program. You would also have two solenoids set for movement (Left:up/down and right:up/down) and the two solenoids are separately controlled by the VSA program. In that diagram you have I would think you would only have the control of up/down.

NO, not sure I understand...you would only use 1 solenoid as you want all bags firing at exactly the same time straight up so the mechanism doesn't get off square and jam.

Control can be a simple stamp, pic, prop1 or what not. VSA might be overkill we'll see. I need to get the mechanical parts working first!!!! Then add control

I like these, seem very simple we'll see:



Gonna hit the shop today and see what I can come up with

-Slyder