How to Build a Motion-Activated Coffin for Halloween

Motion-activated coffins can set just the right mood for any creepy Halloween front yard or spook house. The coffin's lid opens when someone passes by the motion sensor. This Halloween prop does take some skill and time to create, but the people at your party or your local trick-or-treaters will be left screaming when they see it.

Things You'll Need

• Saw
• 3 1/2-inch pieces of plywood cut 4-by-8 feet
• Wood glue
• 2 door hinges
• Screwdriver
• 1/2 pound of 5/8 wood screws
• Stain
• Steel wool
• Drill
• Motion-activated door opener
• 12-volt car battery

Instructions

Build a Coffin

1. Cut 2 plywood pieces to 3 feet x 8 feet for the bottom and the lid of the coffin. Cut 2 pieces 3 feet x 1 foot for the ends of the box. Cut the 2 sides of the coffin 1 foot x 8-1/4 feet.

2. Lay a 3-by-8 foot board on a flat, hard surface. Place an end piece vertically at the end of the board at a 90-degree angle.

3. Apply wood glue to the place where the boards meet. Secure the boards together by drilling two screws through them.

4. Glue the other end piece to the opposite side of the 3 x 8 board with the same process. Put 2 wood screws into each corner. This is the base and end of the coffin.

5. Secure the 1 x 8 1/4 foot boards to the sides of the frame. Secure the boards with wood screws.

6. Turn the coffin over and attach 2 hinges on one side.

7. Slide the remaining 3 x 8 foot piece onto the coffin and attach the hinges.

8. Stain the coffin. Age it by rubbing it with steel wool. Add a headstone with lettering and drape it with cobwebs and plastic spiders.

Add the Motion Detector

1. Purchase motion detectors and door opening kits with motion detectors at Home Depot or Lowe's. Mount the motion detector to the front of the coffin. Find an inconspicuous spot near the bottom.

2. Drill holes in the side and top of the coffin to mount the opening device inside the coffin.

3. Wire the door opening device to the battery. The device has wires included and instructions about how to wire it. Place the ground wire on the black side of the battery.

4. Place the coffin in place and wait for the Halloween fun to begin.

Tips & Warnings

• Wire fog machines and lights into the motion-detector and battery.

Resources

• Read this Article in Spanish