Low cost Halloween pop-up character

After looking at some of the available kits for making a pop-up character, they seemed of good quality but I have a lot of left over stuff in my garage and felt I could build one for less than the cost of the kit. And I offer this for the do it yourself person who may have some left over lawn sprinkler pipes as I did. This one works on compressed air and 110VAC or 12VDC to operate the air valve. If you use a remote as I did, I would go with the 110VAC. If you want to use a foot switch or step on to activate pad then I would recommend the 12VDC version.

Step 1 Here is what you need:

-30" of IPs PVC pipe (this is the thin walled stuff)
-30" of Schedule 40 PVC pipe(this is the thick walled stuff)
-NPT Pneumatic Valve, from STC, PN is 2P025 -3 (this is the 110VAC you can also buy a 12VDC version if preferred), the site is: http://www.stcvalve.com/Process%20Valve.htm?gclid=COqB7_vF8pUCFRNOagodHHT1ew
-1, 1/2" PVC Cap
-1, 3/4" PVC Cap
-1, 1/2" 90deg PVC Elbow to 1/2" NPT thread
-1, 1/4" NPT Female thread air chuck (sometimes called plug)
-Various 1/4" NPT thread extension pipes and adapters
-22mm x 5 M Heat Shrink Tubing Item 98068 from Harbor Freight, http://www.harborfreightusa.com
-Garbage can
-String
-PVC Adhesive
-1/2" to 3/4" thick plywood about 2' x 2'
-2" wood screw
-1, 1/4" diameter wood dowel 5" long
-Automotive Hose clamp
-3ft lamp cord with plug on end
-Scary (Lightweight) Head such as a Halloween mask, skull, pumpkin (your choice)
-Westinghouse Wireless Remotely Operated Switch Model No. 28068 or equivalent - web site http://www.gatecomusa.com/product_info.php?products_id=2048

Optional Items:
-Sound FX Scream Unit ( bought this item at a costume shop, could not find a web source for it)
-Micro Switch - Normally Closed (when not depressed)
-1, 3/4" PVC Tee
-Threaded rod with 4 matching nuts.
-S bracket
-90 degree bracket
-Red light hooked up to a flicker circuit, see good Instructable at http://www.instructables.com/id/Haunted-Flicker-Light-Adapter/
-Fog Machine

Comments

[leego10]

sick! now bury the trashcan in ur yard haha

[mkerr1]

Actual pneumatic cylinders can be purchased on Ebay for about $5 each if you watch. Gets rid of the whole PVC cylinder debate and just adds extra safety to the whole project.

I also STRONGLY urge people not to use PVC for cylinders even though I have seen them work flawless in a haunt for years. Over 20 years experience here.

[Improviser]

This a very bad idea. You can check with just about any Halloween prop maker with experience (myself included with over 15 years) and they will tell you that using PVC for any pneumatic application is bad. PVC is meant to carry water under pressure, air is a totally different animal that will degrade the PVC and cause it to fail by exploding into shrapnel. PVC also fails quickly if it gets cold. For safety always use cylinders designed/rated for pneumatic applications. My pop-up props use them and they were cheap (like $12 on ebay). It's not worth the chance of causing injury to anyone.

Read the information here if you don't believe me:
http://www.phantasmechanics.com

[Back Roads]

Sorry to all I have been busy working other things and haven't checked this for some time. But a side note I have been using this prop now for 3 years. No problems to report.

So my response to Improviser, the web link you posted to prove your point does not work. I would also ask you and others not to keep spreading internet folk lore without knowing the facts.

So here are some facts. The issue of PVC shattering is common among plastics and is called Glass-transitioning. This is where the molecules freeze and can not take any impact (under pressure or not). To find this temperature of a plastic one should consult a proper source such as the "Modern Plastics Encyclopedia." In there you would look up Brittleness Temperature. For PVC you will find it to be -7 deg F. You will also find PVC is good up to 150-200 deg F continuous use. You can find the same information from suppliers like Port Plastics at http://www.portplastics.com/.

Further investigation of PVC you will find air does not degrade PVC. A common sense test of this would be if it did, home improvement stores could not store the products on the shelf in the open.

To make one nod on, air versus water in PVC pipe. Water does not compress (much) so if it is under pressure in a PVC pipe and there is no air (also compressed) in the pipe, and the pipe is below -7 Deg F, and it is struck with a sharp object, the pipe could shatter. But since water will expand very little, it will carry PVC fragments only a short distance. A PVC pipe with compressed air under the same conditions will Fail in the exact same way. However since air expands it will carry PVC fragments with it a much farther distance as the air expands to equalized with the ambient conditions.

So if you want to use PVC in North Dakota in the middle of winter, outside, you may have a problem, whether it is under pressure or not. For people who live in the south west we don't have a lot of problems with the stuff.

Side note to the Spud Gun crowd, I noticed MythBusters had used a PVC spud gun on their Duct Tap Tater Tosser episode. They claim they are professionals with years of experience.

[Improviser]

Yes,

Unfortunately Doug Ferguson's site phantasmechanics.com has gone offline, the owner retired. He had many years of experience in prop building and is known as the creator of several props for many you see today. The link was to a good article on the hazards of PVC under air pressure and his experiences.

If you are in any business that deals with compressed air (or any gas) you will know that OSHA has severe penalties for use of PVC pipe to carry air. It is just not allowed for good reason.

Maybe this government website will help:

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

A quote from the United States Department of Labor OSHA document:

It is our position that PVC pipe shall not be used as a means of transporting compressed air. This position follows the manufacturer's own statements that PVC is unsuitable for compressed air systems. We do allow the use of certain ABS materials that are specifically designed for compressed air systems. One such product is "Duraplus" air line piping system ABS pipe. However, as in any such system, the manufacturer's specifications on acceptable pressure and temperature considerations must be followed.
******

Another United States Department of Labor OSHA document: Quote:

Last year, a section of PVC pipe being used for compressed air exploded 27 feet above a warehouse floor. A fragment of the pipe flew 60 feet and embedded itself in a roll of paper. Fortunately, nobody was in the area at the time.

A PVC pipe explosion in a new plant in Selah broke an employee's nose and cut his face.

PVC piping buried 3 feet underground at a Yakima manufacturing plant exploded, opening up a crater approximately 4 feet deep by 3 feet across.

Only one type of plastic pipe has been approved for use with compressed air. That pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for compressed air supply.
******

PVC shatters into pieces
ABS splits lengthwise

You may be lucky is all. I would hate to be the one standing nearby when it fails. Water in PVC only transfers energy, air stores potential energy. So even at relatively low pressures, PVC can suddenly release a tremendous force.
If you rally doubt any of this, you really need to talk to the manufacturer of the PVC pipe you intend to use.

[GTechno13]

I have a PVC pneumatic spud gun which I like to shoot snowballs in the winter. I charge it to 100psi. :) :)

[Back Roads]

Improviser, the portion that pops up is less then 2 pounds. And this design should not be used for anything heavy. The air pressure to activate is only 30 psi, and that pressure is never reached inside the cylinder, because by design it leaks. This allows the prop to return with out a complicated bleed valve. As long as the operator sets this properly, press will never reach to point of exploding. However it may crack over time and at that point it just won't work. If you are designing a pop up to lift a full sized 40 pound prop, then yes design it with the properly rated pneumatics/hydraulics.

[cambigfoot]

screaming voice fx http://www.aseanexport.com/product_info.php?cPath=2_15_18&products_id=247

[cambigfoot]

maybe make a motion sensored light so when you walk by it it triggers the valve

[your dog]

Nice!
for mine i used halloween skull masks. i have a 120 PSi going into 2 tubes. i will add a picture soon.

[Hockey88]

Awesome!!

[ThomasR142]

 i tip my hat to you sir 
very well done!
so simple so great
deffs makein' this one

[Back Roads]

Thanks, keeping it simple took more thinking then I originally anticipated.  Let us know how yours works out.

[frollard]

Overkill: Arduino can add a really customizable automation to provide one-shot-delay functionality so that you can use a mat to set it off, but it won't go off more than once a minute.

More work, but cheaper:
A 555 timer can also be configured to do just this: Configure it in monostable mode. When its 'stable' it activates a transistor that 'allows' the foot pad signal to hit the valve. Then the timer portion locks out the switch for your choice of time. A second 555 timer (or a 556) can be used to keep the valve open for x time (about a second) after the activation. so its not just a quick burst then nothing.
http://www.bowdenshobbycircuits.info/page9.htm#mono.gif explains using a 555 or some digital circuitry to achieve this trick.

[Back Roads]

Thanks for the link, I'll check it out. Since I run this on a portable air tank, I didn't want the kids just standing on it. Then the next set of goblins couldn't enjoy it. On the string I used the nylon type used in construction sites to mark out trench work. The packaging said it had an 80 lbs strength. Since this device does not have much force when it pushes up, The string has held up quite well. I used it because its flexibility. Another option could be parachute cord. Just out of curiosity, I cut the sting and at 30 psi the prop only goes up another 6 inches after it clears the top. and then lands in the trash can. But if it does break I'll spend the night going back to the trash can and putting the prop back on.

[frollard]

Good to hear that! Again, wonderful project!

[nolte919]

Could you use a standard sprinkler valve found at any hardware store? At my local Home Depot they are $13.15 and a 25v transformer from Radio Shack (according to their online catalog) is $6.29. Which would make a valve cost $20, no shipping, and found completely locally. If anyone's curious that sprinkler valve sold at Home Depot take 24VAC, 60Hz; they pull 400 mA inrush and 200 mA continuous. All standard sprinkler valves take the same 24VAC voltage and I think current requirements are similar.

[nolte919]

Also, the spud gun guys have ways of modifying sprinkler valves so they release all their air when a firing tube releases its air. This Instructable recommends this and this site for such modifications.

[frollard]

I use sprinkler valves for upwards of 100psi for just this type of application - easy peasy!

[frollard]

edit: I use the 12vdc models, same valve different solenoid from home depot.

[Back Roads]

An interesting idea. Good news if it works you would use the cheaper sprinkler valves. The more expensive ones have a slow on and off mechanism to keep it from water-hammering, and that might make it to slow. Also you need to remove the anti-siphon valve and plumb into what is left after it is off. Let us know if you try it and how it works.

[frollard]

I did exactly the same in our candy dish with a door-closer pneumatic piston. Simply glue/thread a pipe into the 'adjustment screw' hole - and you've got a self returning *with bleed valve on the source line* piston for cheap. I love your design with the exception of that it relies on a piece of string to prevent an 'international incident'...perhaps something a little more substantial?

Great stuff! 5 from me!

Note - ours is small, and mounted IN the large wicker candy bowl. When someone reaches in for candy, we activate it, scaring the poop out of them.

[desco]

Use a bike pump. It's not much more expensive than building it yourself, a whole lot less hassle, and it'll work much better-- it doesn't leak. You may have to open it and take out a one-way valve. It's usually a loose rubber ball or flap near where the hose goes into the cylinder, and they're usually pretty easy to remove. My father and I made a half dozen using PVC, and we've since converted everything to bike pumps and door openers and gas lifters. Except the 6ft piston that comes out of the sewer, but they don't make bike pumps much longer than 2 1/2 ft.

[Back Roads]

Cool Idea. I didn't have a spare bike pump so never thought of it. I just had a lot of spare PVC I needed to do something with. The bike pumps would save some build and assembly time!

[desco]

Only difference is our PVC pistons had the inner pipe the moving one, and the outer was the cylinder. We glued a middle-sized ring of PVC to the top of the cylinder and the bottom of the piston and sanded it until it just barely fit (instead of using rubber) and used graphite lubricant. No tether... which eventually the impact between the cylinder and the piston caused the glue to fail, and our skull went flying 50 ft out of the barrel. (Probably had the pressure too high too) Since then we started using weed-whacker line for tehters because it's incredibly strong and slightly elastic, so it didn't stress the PVC joints. But eventually we switched to gas lifters and bike pumps because they're pre-made and don't leak, so we don't lose air by leaving them extended. The problem with this is you NEED an exhausting solenoid, or it'll never come back down. Those are harder to find-- new they're very expensive. We ripped ours out of old dishwashers. We started this 15 years ago, so we've gotten a lot of experience on what works and what doesn't. Plus there's already a lot of information on the internet--although "back in the day" it was all newsgroups. I'm not saying your well written Instructable isn't valuable... It's sad a lot of those discussion groups' information we used is probably gone.

[ppatches24]

dude sweeet jod love it

[Padlock]

From stc9.com, how much did they charge you for shipping? I want to submit my order, but am afraid that they'll overcharge me for shipping the piece.

[Back Roads]

The only part I ordered was the valve, and I have to admit I ordered 4 them at once for other project Ideas. I think the charge was $8 for all 4 valves. The other parts I got at Lowe's and Target. Another fun place to hide one might be in a car parked along the walk way :) Also my son added a movie of the pop up in action.

[Padlock]

That's quite a plume you get when the head goes back down.

[MACKattacksnipe]

im going to hide mine in the bushes

[king_zilla]

We have place over here in Idaho that's called the haunted world and they have one of these by the gates. Gets me every time. = ]

Great Job