[PHD]

Here is another project I have been working on. These pneumatic pistons I made have a lot of force just 20 psi due to their small diameter. This is just what I used because that’s what I had laying around, you could use ¾ if you want. Some skill is soldering is required.
½ inch copper tube
½ inch end cap (hole drilled dead center the same size of rod, ream out to fit rod)
Steel rod (I threaded the rod myself)
Faucet grommets (milled down to fit inside the pipe)
Spring to buffer the impact of the rod
Proper sized fittings. Shown are a few types of fittings that can be used. Like with most things use your imagination, but make certain that care is taken with the soldering. These can cause bodily harm.
The long white piston was made from a two piece adjustable 36” mop handle. I was just messing around when I made but found it will work perfect for my “Trash Can Trauma” prop.

As you can see I used one of my pistons for a Pop-Up that will go into a coffin.

 

[PHD]

The rest of the photos

 

[indianaholmes]

Well done. I made similar cylinders from copper tubing about 5 years ago. They still work flawlessly in my Mailbox Trauma. Each had return springs because they are mounted horizontally. They each had different spring rates because I needed the door to open first and then close last. Here's a video of it in action;

Here's a picture of the back insides of the colomb that the mail box is mounted in. The big cylinder is visable;

More pics in photobucket.

 

[indianaholmes]

I forgot the main reason I posted was to tell you that I used leather washer/seals from Ace Hardware. Always flexible and will fit any imperfections or sizes in that range of tubing. They are also extremely durable if greased well.

 

[Monstermaker]

What size of a throw could you achieve with that set-up? I'm just curious because you got me thinking of a prop now.

Thanks.

 

[indianaholmes]

You can get anything you want. Look at PHD's mop handle cylinder. He must be getting over 4 feet. The only problem with this setup is it will most likely be a single action cylinder so you would need gravity or a spring to reset it.

 

[milemarker]

Very nice . Good idea . I made some out of those piston shocks for hatchbacks ( cars ) - they're also used on some smaller cars hoods to help them stay lifted.
I drilled a small 1/8 inch hole in the bottom to let the pressurized oil out . Then I reamed the hole bigger to fit the brass fitting into and then brazed it in place . Made 3 of these so far ( still testing for durability and dependability )
These , like yours , only require a minimun amount of air pressure to get the prop activated .
With yours , did you use silver solder rathter than the softer lead solder ? Reason for asking - the silver solder joints will hold stronger than the normal solder would .
Again , good idea .

 

[PHD]

What size of a throw could you achieve with that set-up? I'm just curious because you got me thinking of a prop now.

Thanks.

Mike the travel distance would only be limited to the cylinder and the push rod used.

 

[PHD]

The Pop-Up I have shown is 24 inches, the piston is 8 inches and the travel is 7 inches. I just tested it last night and will lift 1 pound to the full vetical in one second @ 40 psi. It should have more than enough power to life a foam head, clothing and foam body parts to a sitting position in the coffin.

 

[PHD]

Very nice . Good idea . I made some out of those piston shocks for hatchbacks ( cars ) - they're also used on some smaller cars hoods to help them stay lifted.
I drilled a small 1/8 inch hole in the bottom to let the pressurized oil out . Then I reamed the hole bigger to fit the brass fitting into and then brazed it in place . Made 3 of these so far ( still testing for durability and dependability )
These , like yours , only require a minimun amount of air pressure to get the prop activated .
With yours , did you use silver solder rathter than the softer lead solder ? Reason for asking - the silver solder joints will hold stronger than the normal solder would .
Again , good idea .

I'm going to try one of those this weekend, I have it right here next to me now.

 

[PHD]

Well done. I made similar cylinders from copper tubing about 5 years ago. They still work flawlessly in my Mailbox Trauma. Each had return springs because they are mounted horizontally. They each had different spring rates because I needed the door to open first and then close last. Here's a video of it in action;

Here's a picture of the back insides of the colomb that the mail box is mounted in. The big cylinder is visable;

More pics in photobucket.

Very Nice, I like....

 

[Monstermaker]

PHD....how is the air exhausted from the cylinder? I can't quite tell from the pictures.

Thanks....

 

[deveds2]

Say, that is really cool. What about using screen door cylinders instead? They are about $10 at the local hardware store and last a few years.

 

[milemarker]

screen door cylinders have been uised for years on air pneumatics for Halloween props . Works good , as long as you don't over do the pressure .

 

[indianaholmes]

Screen door closers are a cheap cylinder choice, but if you need a different size, this is an alternative that is much safer than a PVC cylinder. It worked well for me when I couldn't find the cylinder I needed on ebay and is a lot cheaper than buying from Bimba or another manufacturer.

 

[FeelNecro]

Has anyone tried making these pistons out of PVC ?
Just wondering if it will work.

oops didn`t see post just above mine about PVC

 

[[email protected]]

Has anyone tried making these pistons out of PVC ?
Just wondering if it will work.

oops didn`t see post just above mine about PVC

Yes many have and don't do it they go boom and hard plastic shrads go flying everywhere!eyes,windows,TOTs.

 

[FeelNecro]

Yes many have and don't do it they go boom and hard plastic shrads go flying everywhere!eyes,windows,TOTs.

I can see how that might happen.

What about schedule 40 CPVC ?