Pneumatic Props
Pneumatic props use compressed air to create fast, powerful movements — pop-up corpses, lunging figures, slamming coffin lids, and jumping spiders. They're the high-end of home haunt animatronics but not as complicated as they sound. If you can connect air fittings (push-to-connect or threaded), you can build pneumatic props.
How It Works
A compressor fills a tank with air. A solenoid valve (controlled by a trigger signal) opens and sends air to a cylinder. The cylinder extends (or retracts), creating linear motion. That motion raises a prop, opens a lid, or shoves a figure forward. When the valve closes, a return spring or second air line retracts the cylinder.
Key Components
- Air compressor — A small pancake compressor (2-6 gallon) is sufficient for most props. You don't need high PSI — most haunt props run at 40-80 PSI. Compressor noise can be an issue; run it away from the display or inside the garage.
- Cylinders — Available in various bore sizes and stroke lengths from AutomationDirect or surplus suppliers. A 1.5" bore, 12" stroke cylinder handles most pop-up props.
- Solenoid valves — 12V or 24V, controlled by your trigger circuit. 3-way valves for spring-return cylinders, 5-way for double-acting (air on both extend and retract).
- Air line and fittings — 1/4" push-to-connect tubing and fittings are the easiest to work with.
- Speed controls — Flow control valves on the cylinder ports let you adjust how fast the prop extends and retracts.
Pop-Up Prop Build
The classic pneumatic haunt prop: a figure that pops up from behind a tombstone, barrel, or ground box when triggered.
- Mount a cylinder vertically in a box or behind a prop
- Attach a prop (skull, corpse bust, monster head) to the cylinder rod
- Connect air supply through a solenoid valve
- Wire the solenoid to a PIR sensor or pressure mat trigger
- Adjust flow controls for the right speed
- Add a simultaneous sound trigger for maximum scare
Safety
For a gentler introduction to prop motion without compressed air, see moving props without pneumatics.