This project uses conventional materials in an unconventional way. There are
no guarantees that the completed project will be suitable for your intended
purpose or safe for you to operate. You must accept complete responsibility for
any damage or injury that happens while working on or using your completed
project. The instructions provided in this document are intended to be used as a
rough guide. Parts for this project vary in quality and design from manufacturer
to manufacturer and may not be identical to the ones used when this document was
put together. You will have to use your best judgment when selecting and
assembling the materials for this project – it is likely that minor
modifications will have to be made to account for the variations in building
materials.
This project requires the use of tools and chemicals that are hazardous when
used improperly. You should be familiar with the tools and follow all
instructions & warnings provided by the manufacturer. Please wear proper safety
equipment when using power tools and provide adequate ventilation when working
with chemicals like PVC cement.
The final product uses compressed air for activation. Compressed air can be
very dangerous when used improperly. The modified screen door closer is not
rated for pressure and poses a danger of explosion at any time. Use the minimum
pressure necessary and DO NOT EXCEED 60 PSI AT ANY TIME. If your prop does not
operate at pressures lower than 60 PSI you have done something wrong or are
trying to use it in a manner that it was not intended for (i.e. trying to lift
too much weight). Typical operating pressure is 40-50 PSI when fully loaded with
costume (25-30 PSI unloaded).
Note: You might find it easier to pre-drill the holes in the before you
secure the wood dowel with screws. Pre-drilling also makes it easier to see when
the dowel piece is in the correct location in the PVC pipe.
Please Note: Before you begin gluing the assembly together, it is a good idea
to dry fit all of the PVC pieces to make sure that no adjustments are needed. Once you have made sure that everything fits together properly
and you have all of the necessary pieces, you can begin gluing the assembly
together. There are several pieces that do not get glued together, so be careful
not to glue those pieces permanently in place.
There are several sub assemblies that form the full pop-up platform.
| Attach 2 elbow fittings, 2 Base (D) pieces, 2 more elbow fittings
and the 1 remaining base (A) piece to form the assembly shown in the
image to the right.
These pieces get glued together. |
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| Insert the 2 upright supports (C) into the open T fittings as shown
in the image to the right. These pieces get glued together.
You may be wondering why the assembly does
not sit flat on the table. Why waste the 2 extra elbows making the
assembly raised in the back? Well, after building several of these
assemblies I found that by slanting the uprights forward a bit the final
prop not only comes up, but forward a bit more too. It makes for a
more natural motion and a better scare (in my opinion). I had
propped them up in the past using a brick or something similar. In
the interest of simplicity and reliability, I got rid of the brick and
started building this slant in to the props during construction so that
I can just set up the prop, plug it in and be done with it. The
shape also lends itself for cradling a sandbag for added stability. |
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| You will now need to create 2 identical lever ends. To assemble a
lever end, you will need 2 elbow fittings, 2 T fittings, 2 lever pivots
(B), 2 lever ends (E) and 2 of the pieces created in step 1 as in the
image to the right.
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| During the assembly process you will need to slip the two pieces
created in step 1 on to the 2 lever pivots.
Only the lever ends get glued to the elbow and T fitting. The
rest of the assembly is held together with self drilling sheet metal
screws.
Once the 2 pieces in step 1 have been slipped on to the lever pivots,
you can assemble the other side of the lever end. You should end up with
something that looks like the image to the right. |
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| Repeat step 5 to create a second lever end as shown in the image to
the right. |
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| The body is assembled from 3 T fittings, 2 body uprights (H),
2 shoulder pieces (F) and 1 neck piece (G) as shown in the image to the
right The neck and shoulder pieces get glued together, but the body
uprights are screwed together. |
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| At this point you should have 4 sub assemblies and the remaining 2
lever supports (I) as shown in the image to the right |
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| Attach one of the lever end sub assemblies to the base assembly as
shown in the image to the right. the lever end sub assembly is glued
to the base assembly uprights. |
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| Attach the 2 lever supports to the lever end assembly as shown in
the image to the right. The lever supports are glued in place.
The reinforced lever end (LI) should be
connected to the bottom T fitting with the reinforced end of the PVC
closest to the upright side. This will be where the piston end attaches.
|
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| Attach the body assembly to the remaining lever end as shown in the
image to the right. The body assembly is screwed to the lever end
assembly.
|
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| Attach the lever end/body assembly to the base assembly as shown in
the image to the right. The lever supports are glued to the lever
end/body assembly.
This completes the armature portion of the assembly. |
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| The sheet metal screws prevent you from accidentally gluing the pivoting pieces in
place and allow you to make changes to the height of the body of the
prop to adjust to whatever size gravestone you end up using and replace
the pivot pieces if they become worn out. |
| The image to the right shows the locations where the body side of
the assembly will be held together with screws instead of glue.
The blue circled "+" joints should be screwed together instead of glued.
Click on the image to enlarge it so you can easily see the screw
locations. |
(click on the image to enlarge it) |
| The image to the right shows the locations where the base/support
side of the assembly will be held together with screws instead of glue.
The blue circled "+" joints should be screwed together instead of glued.
Click on the image to enlarge it so you can easily see the screw
locations. |
(click on the image to enlarge it) |
| The remaining joints will be glued together using PVC
cement. Take your time and glue each assembly together in sections so
everything stays aligned properly. PVC cement sets VERY quickly,
so it is critical that you have your assembly well thought out before
you start gluing. I recommend using a PVC cement that is colored.
There are red and blue multipurpose cements that are excellent choices
for this job. Why colored cement? Clear cement is very hard
to see and you are more likely to forget to glue a joint together if it
is hard to tell which ones are done and which ones are not glued yet. |
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| You may have to modify these instructions to fit your make and model
of screen door closer if you cannot find the exact brand used here.
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| Remove the bleed valve screw and trim off the protruding section
(2nd hole) using an angle grinder with a cutoff wheel or hacksaw. It
helps to have a vise to hold the piston still while you cut off the
excess metal. Do not crush the piston housing in the vise. You should
end up with something similar to the image to the right. |
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| Drill out the threaded hole in the bottom of the piston. Be careful
not to drill into the piston diaphragm. You will need to drill very
slowly and keep the drill bit aligned with the existing hole in the
piston. Tap the hole using a 1/8 inch NPT tap as shown in the image to
the right. Once you have a good clean set of threads, use your air
compressor to clean/blow out all of the metal shavings that have fallen
inside the piston. |
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| Screw in the 1/8 inch NPT threaded elbow using Teflon pipe tape
thread. Do not over tighten. Align the elbow as shown in the image to
the right. Attach 16 inch section of airline to the other end of the
elbow and secure with pipe clamp. |
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The piston L brackets are fashioned from 1.5 inch x 1.5 inch L channel
bar aluminum. I simply cut the L bar into 3/4 inch pieces and drilled
out the holes for mounting them to the reinforced PVC base piece.
You should be able to find standard steel or brass L brackets in the
hardware department of your local building supply store which would make
construction of the two L brackets much easier. I would recommend
getting an L bracket that is 1.5-2 inches in length and no wider than
3/4
inch.
Depending on the model of screen door closer you choose you will need
to drill a hole that aligns with the piston's pivot hole. You may
have to round off the corner of the L bracket so that the piston can
pivot without binding. Take a look at the image to the
right. You need a minimum 1.5 inch height on the L bracket to
allow for the 1/8 inch NPT elbow and hose clamp. |
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| The 2 L brackets need to be spaced far enough apart so that the
piston can slip in between and pivot easily. The piston is attached to
the L brackets with a #8 x 32 x 2” bolt, 6 #8 washers and a #8 x32 nylon
lock nut as shown in the figure to the right.
Do not over tighten the nylon lock nut. The piston needs to be
able to pivot, so a little space needs to be provided so that the
washers do not bind up against the piston mounting point.
I recommend putting the two L brackets on the piston with an extra
washer in between the L brackets and then marking
the mounting location on the reinforced PVC base piece. That will
ensure that you have the correct spacing between the L brackets for the
piston and washers.
|
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| The final position of the L brackets will be off center because the
upper piston mount will attach to one side or the other of the
reinforced PVC lever supports. You want the piston to be
perpendicular to the base, so when deciding where to mount the L
brackets to the reinforced base keep in mind where the upper mount for
the piston will be attached. |
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| The upper piston mount will be attached to the reinforced lever
support using a #8 x 32 x 1.5 inch bolt, 4 #8 washers and a #8 x 32
nylon lock nut as shown in the image to the right. Do not over tighten
the lock nut so that the upper piston mount does not bind. It
needs to be able to rotate on the bolt.
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| Finding the correct location for the upper piston mount to be
located can be a bit tricky. It depends on the size of the L
brackets you used to mount the piston and the amount of throw that your
piston has. With the brand of piston I used, it usually came out to
somewhere between 3.25-3.5 inches from the end of the reinforced lever arm. |
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| You can temporarily attach the piston to the lever arm with a 3/4
inch wood screw and then apply a small amount of air pressure to extend
the piston to it's maximum length to determine the best location for
mounting the piston. On my first prototype I drilled small test
holes every 1/2 inch to determine the best mounting location as in the
image to the right. Once you have a location that allows the piston to
run through it's full range of motion you can drill all the way through
the reinforced lever arm and attach the piston using the bolts, washers
and nylon lock nut. Do not try to run the prop for any length of
time with the temporary wood screw in place. The pivoting action
of the piston mount will unscrew the wood screw over time. |
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| At this point you should have something that looks similar to the
image to the right. Ignore the clear vinyl tubing in the image for
now - that is part of the exhaust/noise making assembly. |
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| The arms of the prop are attached by running a 6 foot length of
bungee cord (or surgical tubing) through the shoulders and the PVC
pieces for each arm. The arms are secured at the wrists with 2
screws through the bungee cord. See attached image Once the
parts have been glued together and are dry, you can move on to getting
the assembly ready for a costume.
Attach the foam head by slipping it on to the neck. |
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| Adding 1 inch ID foam insualtion to the shoulders and arms of the
prop will give it a bit more bulk and pad the moving parts so that if
they accidently come in contact with something they will not be as
damaging. I used packing tape to secure the foam pipe insulation in
place. The foam insulation serves 3 main purposes. First,
it adds some bulk to the PVC shoulders so that the prop doesn't look 1
dimensional. Second, the foam pipe insulation gives the clothes
something to stick to so that the shirt doesn't just slide off one
shoulder or the other. Last, but not least, it pads the part of
the prop that (if fired off at the wrong time) would hit someone or
something unintentionally.
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| If you are using a solenoid valve and regulator at the
prop, now is the time to get those items set up and tested. |
| You will need a bypass valve regardless of what type of valve
(manual or electric solenoid) you use. The bypass valve serves 2
purposes. First, it allows air to escape from the system so that
when pressure is no longer being applied to the system the prop will
return back to the hiding position. The second reason you need a
bypass valve is to give you some escaping air to play with as a noise
maker. In the image to the right, the small brass knobbed valve (on
the left) is the bypass. The valve with the gauge is a pressure
regulator that can be set at the prop itself. It
should be set to slowly let the air escape from the system so that when
pressure to the prop is cut off, the prop slowly returns to neutral.
If this valve is set to let too much air escape, the prop may not
activate or will return to the down (neutral) position violently.
If it is set to not let enough air escape, the prop will take a long
time to return to neutral or may stay activated indefinitely. The black
air hose in the image goes to the props piston. |
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| At the compressor I have my electric solenoid installed (the piece
with the black wires coming out). You can operate the prop by
installing a manual air valve in the line somewhere, but I prefer to
automate the valve by making it electric and plugging it into a remotely
controlled switch.
Locating the valve closer to the prop gives you faster response and
allows you to run more than 1 prop at a time. For illustration
purposes (and so I can take advantage of the electrical supply I am
already using at the compressor, I've located the electric valve at the
compressor. It's easiest to set your line pressure if you locate
your valve after the regulator, but either way will work. |
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| It's a messy image, but it shows generally how to hook up the
prop... An airline runs between the compressor and the prop. At
the compressor I install my electric valve. The valve is plugged
into a remotely controlled switch (in this case an x-10 controlled
switch). The remotely controlled switch also powers a small spot
light that is aimed where the head of the prop is when activated.
So, basically when I hit my little remote control, the prop jumps up
and is lit by the spotlight. When I deactivate my remote, the
light turns off and the prop slowly returns to neutral. |
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| The last piece of the project is to make some noise. That is a
really easy thing to do with this set up. You simply attach
whoopee cushion valve to the air escaping from your bypass valve.
So, whenever the prop is activated and receiving pressurized air, it
also makes a razzing/screeching sound. Adding an alligator clip
makes a screeching sound instead of a razzing sound. Using a piece of vinyl
tubing you can move the location of the whoopee cushion where it has the
maximum effect. In the image above the blue object is the valve
cut from a whoopee cushion and zip-tied to the output side of the vinyl
hose (and an alligator clip attached). |
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| At this point, you are basically ready to add a costume
and fine tune your new prop. |
| Dressing your prop in a costume is very easy. I usually safety
pin a very small pillow to the chest of the assembly. While this
is not necessary, I think it adds some fullness to the prop and makes it
look even more realistic. The pillows are the standard travel
pillow sized pillows that you find in the automotive or pillow section
of most department stores. |
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| I pull a pillow case or black fabric bag over the Styrofoam head.
The black fabric will conceal the white Styrofoam head through the eye
and mouth slots of your mask and give you something to safety pin the
shirt to if necessary. It also helps to bulk out the head a bit.
Most Styrofoam heads that I have come across are way to small to fill
out the features of a store bought mask, so the pillow case also adds
some filler for this purpose. |
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| Next, dress the armature in your shirt. In the image to the
right I am dressing the prop in a shirt that came as part of a complete
costume (shirt, pants, mask and gloves). You can get complete
costumes like this for $25-$30 at most department stores. It saves
a lot of time and ensures that you get exactly the look you intended. |
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| Once the shirt is pinned in place, attach your mask. I use
stick pins in several places around the edge of the mask to keep it from
shifting around during use. |
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| The final prop ready to set up. I do not have any images of the
hands available, but they were simply attached by zip-tying them around
the wrists. We filled out the fingers and palm area by stuffing
the gloves with wadded up pieces of plastic grocery bag.
I have also added coat hanger wire to the fingers in the past to make
the fingers somewhat moveable, but I have found that in the dark, most
people don't notice the hands much and I can affix them to the grave
stone, wall or whatever in a manner that makes them appear somewhat
natural and realistic.
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Once you have your prop dressed and ready to set up. Verify that your
compressor regulator is set at 60 PSI or less. If you are not using a
pressure regulator at the prop, start with 30 PSI and slowly increase the
pressure at the compressor until the prop fully activates. If you reach 60
PSI and the prop does not fully activate, you have too heavy a costume on your
prop or have assembled something incorrectly.
The solenoid has “IN” and “OUT” stamped on the ports. Make sure that you plug
the “IN” side of the solenoid into the compressor. The solenoid is a
normally closed type no air will pass through the solenoid until 110V power is
applied. Make sure that the power to your electric switch is off and then
plug in the solenoid. Plug the male quick disconnect from your air line
into the “OUT” port on the solenoid. When your switched extension cord is
turned on, the solenoid valve opens and lets pressurized air through the hose to
the grave jumper. When the switch is turned back off, the solenoid valve
closes and cuts off the supply of air to the hose.
The grave jumper air assembly includes a bypass that allows the air to escape
from the line and the prop returns to the lowered position.
You will need to make adjustments to the air pressure to make the device
operate the way you want once you have it dressed and set up where you want it.
If your grave jumper is not moving or is moving too violently (and you have
your compressor set to 60 PSI and the solenoid or manual switch is open), you
will need to make some adjustments to make your prop work properly
You only want enough pressure to activate the prop – too much pressure and you
risk blowing apart the prop or the air cylinder. I have tested the piston up to
60PSI with no problems, but you should be careful when operating the prop that
you don't overload the piston.
The bypass valve should not be completely closed. It should leak air at all
times when the prop is activated. If you close it all of the way the prop will
take forever to return back to neutral (down). You can adjust how fast your prop
returns to neutral by adjusting the bypass valve.
If you have installed a pressure regulator at the prop itself, you can run a
higher pressure at the compressor. This will also allow you to run more
than one pneumatic prop or effect at a time and give you a TON of control over
the fine tuning of the prop. I highly recommend investing the $14-$25
dollars to install a regulator at the prop. I don't know how many times I
have failed to double check the regulator at the compressor and almost destroyed
my prop by running 100+ PSI through the piston. I am 90% sure that once
you have created a pneumatic prop you will want more of them which will almost
guarantee that you will want to be able to fine tune your props individually
instead of trying to make everything run smoothly at a fixed line pressure.
If
you run an electric solenoid, you can plug a light into the same switch as your
solenoid and have your prop spot lighted when it is activated. You can
hide the prop a lot better if there is little or no light on it when it's not
activated.
