How scary would it be to have a casket with a dead guy in it open up and he rise from the dead. Wow!
Well it is quite a big project but well worth it! This is a self contained (well it does have 1 extension cord running to it) Casket that opens and a corpse sits up - all at the push of a remote control button.
There is nothing that adds more realism to the prop than an actual casket. A 'real' one. Ours is a two-door, low miles and we are the original owners. However, obtaining a 'real' casket can be somewhat difficult. The casket challenge has eased up a bit with the new laws that require that funeral homes must accept caskets from outside sources. The internet has also helped with competition driving down prices. Most, if not all casket sellers are targeted to ship to a funeral home, so the tricky part may be to find someone who will take delivery of your casket or sell you one near cost.
Aside from the casket challenge the project can be broken down into five main areas:
1) Corpse (Who we affectionately call 'Bob')
Step 1: Bob (the Dead Guy)
The mask had the eye holes closed off from behind with ping-pong ball halves with red LED's hot glued in place. The mouth area was closed off from behind with an empty ice cream pint container with a small speaker in it. A t-shaped PVC pipe armature was inserted and the whole head filled with expanding urethane foam. This is NOT 'Great Stuff', foam but two part liquid foam that is mixed one-to-one by volume that expands after mixing to 30 times its volume. It ends up being rigid and weighing about 2 lbs per cubic foot. It does a nice job of filling Bob's head and holding together all the electronics. The LEDs are connected in series with a ~300 ohm resistor (need to pick a value based on LEDs and brightness desired) and are powered by a 9V battery. The speaker was added in case I ever wanted to have Bob speak, but presently that feature is not used.
Photo 2. The latex head was taped to a hole in a cardboard box with the head being outside the box so that the box could act as a staging/funnel area. The whole assembly was placed into another box and back filled with packing peanuts to help support the assembly while the foam set.
Photo 3. Finished foam core head.
Step 2: Bob's Body and Motion Cylinders
Photo 2. Shows the PVC torso installed into the casket.
Photo 3. Shows the PVC 'lever' that is part of Bob's framework with the pneumatic cylinder attached. Bob's torso is located to the left and pivots up as the cylinder contracts.
Photo 4. Shows the lid cylinder position between brackets added to the lid and the sidewall of the casket. A spring tensioned cord was added to slow down the travel of the cylinder as it reached the end of its travel. The pressure needed to get the lid to start to move was too great by the time the lid reached full extension so the cord and spring went taunt at the end of the travel.
Bob's PVC from was intended to have carved foam provide the substance of him. But to save time and money he was ultimately stuffed with newspaper. His clothes were from the thrift store and were distressed by tearing (a rasp works nicely), burning (looks nice but leaves a strong smell), and staining with a salt water solution and with spray paint.
Step 3: Pneumatic Control
Photo 1. Shows the solenoid valves, along with metering valves and exhaust silencers (tissue in cut tubes). The solenoid valves are operated on 24V ac or dc. They have 3 ports, essentially a single pole double through air switch, so that the common port 'A' is at port 'B' when idle and at port 'C' when energized. The valves are connected so that the common port 'A' goes to the cylinders, port 'B' (idle) vents to a metering valve and exhaust silencer, and Port 'C' goes to the pressurized air (actually CO2) source.
in this way the air pressure is off when the valve is idle. When the valve is actuated by applying 24V the pressure is fed into the cylinder causing the desired motion. As long as the valve is actuated the pressure remains and the cylinder remains extended. When the voltage to the valve is removed the common 'A' (cylinder) port is disconnected from the pressure and connected to the metering valve to vent the pressure out of the cylinders slowly so that Bob and the lid return slowly.
There are also metering valves on the pressure side of the solenoid valves to slow the opening/sitting up movement. Otherwise the action take place to swiftly. The whole pneumatic system is run off of a CO2 tank regulated down to about 90 psi. The CO2 is ideal since it is totally silent and since the tank contains liquid CO2 under pressure which turns into gas as the pressure is used. There is tremendous volume of gas available without the noise of compressors or small volume of compressed air tanks.
Photos 2 & 3 Solenoid Valves.
Step 4: Electronic Controls
Photo 1. Shows the general layout of components. The key to the system is two 120Vac time delay relays. These little gems have SPDT relay contacts that close after an adjustable delay has passed after 120Vac is applied. In Bob's case the two relays (one Lid, the other Bob) both receive 120Vac when the remote control when the remote button is pressed turning the system ON. The lid relay has a shorter delay so it closes first, opening the lit. The second relay has a longer delay so that it closes last and causes Bob to sit up after allowing the lid to open fully, plus some delay. When power is removed both relays open and both solenoid valves shift to vent, but the lid metering valve is set to vent slower than Bob's metering valve so that Bob reclines fairly quickly and then the casket lid closes.
Photos 2, 3, 4. Time delay relays.
Step 5: Stand or Graveyard
Photo 2. Bob can also be located in the grave yard ready to be interned. This can be done by providing a reproduction of the funeral home's lowering device made from plastic drainage pipe spray painted silver with gallon paint cans at the corners with inverted cereal bowls, all painted silver.