Every Halloween, my dad and I put together a small haunted house on the porch of his house. Most of the props are remotely controlled lights, sound effects, etc. This year, I made a new prop that was inspired by something I saw at this year's Maker Faire. It's a wooden crate with a pneumatic cylinder mounted on the inside facing toward the ground. When the cylinder is filled with air, it violently lifts the crate up an inch or two. When the air pressure is released, the crate comes crashing back down to the ground. I also put a heavy chain on top of the crate for a great visual and audible effect. There is a colored light bulb inside the crate that is illuminated at the same instant the gas cylinder is filled.
The wooden crate came from Michaels craft store ($10), and the chain was from Home Depot. I used the chain previously with a come-along winch and had it in my garage already.
I am using a 5# CO2 tank to supply gas pressure to the valve at about 100 psi. The valve is a Clippard Maximatic 12VDC, direct-acting 3-way valve.