How to Use Pneumatics in Props

Decide what you want your prop to be, and what you want it to do. For instance, if you have a scarecrow with a slumping head, you could put a compressed air valve beneath the head and use a hinge so that the head will be pushed up when air is blasted out. Alternatively, you could have a hidden prop like a giant rat or a zombie in the ground, and use compressed air to shoot the prop up into the air before allowing it to slide back down by turning off the flow. These are very basic props, but you should start with basics before getting more complex.

Assemble the mechanism for movement. If you have a rat that you want to slide out of a concealed space, then you need to create a basic track for the prop to move on. It could be something as simple as a pole with the scary statue attached to a metal ring around the pole. A pole topper prevents the ring from moving past the end of the pole. If you're making a mobile scarecrow head, make sure that the head is set on a straight path that lets it move up and down by attaching a hinge to the head and the pole, sandwiched between the two and hidden from view.

Run a compressed air hose to the prop and anchor the hose in place. Heavy tape or staples should be used to hold the compressed air tube in place so that it can deliver pneumatic force to the prop. Make sure that the hose is connected to a source of compressed air, such as a small compressor or a bottle of compressed air, and that these sources are enough to move the prop, but not enough to cause the prop damage.

Test the prop. Trigger the compressed air manually and watch how the prop moves. Trigger it in short bursts and in longer ones to be sure that the prop can handle extended air pressure. Close the compressed air again and check that the hose, tape, staples and prop are all in one piece and undamaged. Once you're sure it works, conceal the mechanism, and the prop is ready to be used.

Find a way to trigger the prop during use. You can keep someone hidden nearby and manually trigger the prop. You could also purchase an electronic trigger, where you screw in the compressed air intake into one side, with the exit valve on the other side, and then attach an electronic motion sensor made expressly for the trigger into a central plug. Once you've attached these other components, you have a prop that will go off whenever it senses movement nearby.