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 https://www.instructables.com/id/Haunted-Flicker-Light-Adapter/
-Fog Machine

Step 2: Make the Base

This is simple, just cut a piece of 1/2" or 3/4" plywood in a shape that fits your trash can. Mine is round, and I cut 2 of the edges flat to allow the fog from the fog machine to circulate better. Drill a hole to clear your 2" wood screw approximately in the center. Counter sink the back side. Add two 2" x 4"s to the bottom, on edge and perpendicular to the flat sides. This is to lift the base off the bottom of the can also aid with fog circulation.

Step 3: Make the Strong Back

Cut a piece of 1, 1/4" diameter wood dowel to a length of 5". Carve a V shaped groove along its length. Depth is not critical, but about 1/4" is good. This will be used to help hold and center the 1/2" PVC pipe against the dowel. I would also pre-drill the dowel in the center for the body of the 2" wood screw to keep the dowel fro splitting. Now attach the dowel to your base with the 2" wood screw.

Step 4: Cut the PVC Pipes to Length

My trash can, or excuse me, oversize cauldron is 28" tall. So these lengths may need to be to be changed for your particular situation (for instance if this pop-up will be used behind a tomb stone you made). Cut the PVC (Larger) pipe to 16". Cut the PVC to 20". Now to help keep your featured mask from spinning around each time you use it, cut the larger 3/4" PVC at a about a 45 degree angle about 3/8" up from one end. This does not have to be very exact, just close.

Step 5: Install the Air Seal

My 1st prototype worked without this step but I had to run with about 50 psi of air, and a lot of it. After making this seal on the top end of the 1/2" PVC I could operate my pop-up with much less air, at 30 psi. Cut 2 pieces of 22mm x 5 M Heat Shrink Tubing. One should be 1/4" long. The 2nd should be 3/4" long. Heat shrink the shorter pieces first about 1/2" down from one end of the 1/2" PVC. Now put the longer one over this and center it over the smaller piece before heat-shrinking. The result should have a flat bulge in the middle. Now lubricate the end with the heat shrink. Since this is a relatively slow moving item (at least when comparing to the speed of sound), I would recommend just using candle wax. No need to heat it, just rub it on the heat shrink. This worked on mine with no problems.

Step 6: Make a Spacer

What you need is half of the end cap with the top removed. This will allow you to clamp the 1/ PVC to the dowel with only 1 automotive hose clamp. I cut mine on a band saw by putting the end cap on a scrap piece of PVC. This can also be done by the Arm Strong method using a hack saw. Cut the top off 1st. Then turn the cap and scrap PVC 90degrees and cut the end cap in half.

Step 7: Assemble the Valve Assembly

Attach 1/2" 90deg PVC Elbow, Female thread air chuck, and Pneumatic Valve with your various fittings. Pay attention to the arrow on the Valve. It shows the direction of the air flow and should point toward the 90 deg Elbow. The picture shows a short pipe between the valve and the Air Chuck. I later extended this so the air chuck was just sticking outside of my trash can. I found this made it easier to hook up the air supply.

Step 8: Assemble the Pneumatic Lift Assembly

Glue the PVC into the elbow. Place the assembly up against the V-groove of the Strong Back (wooden dowel) with the elbow down against the plywood. Place the Spacer you made in step 6 between the PVC and the Strong Back's groove near the top of the groove. Glue this into place. Now place the Automotive Clamp over the PVC and the Strong Back. Locate it way between the Elbow and the Spacer then tighten. Slip the PVC over the PVC and check the top and verify the 2 are almost level. If not, trim one or the other until they are. Then glue the PVC Cap on the PVC. If you are the anxious type, the system can now be tested, but be warned the PVC will launch like a rocket (hey maybe that is another Instuctable?).

Step 9: Safety Restraint

Tie a strong nylon string from the base of the PVC to the Air Chuck. I added some glue in both places to help hold the knots in place. This does 2 things. One is making it safer for the little goblins who will be dropping their treats after this thing surprises them. And, along with the 45 deg cut in the PVC, helps keep your mask looking the same way each time you use it.

Step 10: Install Scary Head

I used a light weight pumpkin head. I drilled a hole in the bottom just big enough to slip the 3/4" PVC cap through. Then put a glob of glue on the cap and put the pumpkin on it. Simple as that. Now the lighter the head the faster it will pop up. I added hair for a more scary effect. This slowed down the ascent as the hair weighed more than the pumpkin head. But it is still fast enough to scare the little kids and get them to drop their candy. I think I could collect what they drop and keep it for next year. Saves money.

Step 11: Hook Up Wireless Controller

Simply crimp on the 3ft lamp cord to the Pneumatic Valve. Now the Westinghouse Wireless Remotely is not the best for this prop, but for the price it does ok. The problem is you would like a momentary push button control that only holds the valve open as long as you hold down the button. This controller is for turning on Christmas lights. So it has a separate on and off button. If your are operating this from an air storage tank, this can waist a lot of air if you leave the valve on. So be warned.

Now the Pop up is now ready to use and install in your trash can. You may want to paint some of the items black, but do not paint the portion of the 1/2" PVC that goes inside the 3/4"PVC. This will cause sticking. Now the rest of this is installing an optional screaming device. So if you are still with me, here is the process.

Step 12: Add Screamer - Optional

I found a small press to scream device at a costume store. I have not been able to find an on line sources. So if any one does please add it as a comment. This screamer was a self contained item that when you squeezed it, it would let out a pre-recorded screech. I took it apart and it was obvious where the connection was made to activate it. So I removed the rubber contact and soldered 2 wires. So when the wires are touched they activate the scream. Now solder the other ends of the wires to a Normally Closed Micro Switch.

Cut the 1, 3/4" PVC Tee as shown in the picture so you end up with an L shape. Glue a flat piece of plastic to one side also as shown. This Activation Plate will be used to activate the switch. Now glue this assembly to the base of the moving portion of the PVC pipe.

Next you need a holder for the Micro Switch that can be adjusted vertically. I used a scrap piece of S shaped metal for the base and a piece of angle aluminum to hold the switch. Drill a hole in both of these pieces that will allow the threaded rod to just pass through. Glue or bolt the micro switch, as shown, to the angle aluminum. Measure and cut the threaded rod to be long enough to hold the switch up past the Activation Plate. Screw down the S bracket and install the threaded rod. Secure with nuts on each side of the S bracket as shown. Secure the Angle bracket to the top also with 2 bolts on opposite sides. Adjust the top bolts until the Micro Switch is depressed. Now when the head pops up it will set off the screamer.

Now add a fog machine such that it blows the smoke in the trash can and add a red flickering light inside the can and your are ready for the nights fun. I'll take some more pictures after it is set up with all the decorations. Videos will be posted soon as well.

Step 13: It Is Now Ready for Action!

You now have your pop-up character ready to scare the next group of visitors at your doorstep.

Update: My son has finally uploaded a video of it working.