I've already started working on the Halloween Spectacular for next year. I loved how the pneumatic Grim Reaper worked out; so I'm expanding on the concept for next year.

The 2006 edition of the Reaper was run with an vinyl tubing extension on a standard blow-gun (attached to the air compressor). This worked well, but had some limitations. For example, the aperture wasn't wide enough. Not to mention, the blow-gun in your hand was a dead giveaway.

The 2007 edition is far superior. I've decided to have two different air cannons for the upcoming year. The Reaper will continue to have a cannon, but I'm also adding a second cannon in the archway. This one will point downward, and will get people as they walk through. You won't expect this one.

Here's the plan. I've built a modular controller for solenoid valves (electrically triggered air valves). I've hooked up a radio transmitter to a relay board. When I push one of the buttons on the remote, the relay is triggered. The relay opens the valve. The valve lets the high pressure air run through the cannon. When I let go of the button, the valve closes and we wait for our next victim.

Here's the toys thus far:



The big box contains the radio board and the relays. The box has one +12v input and two +12v switching outputs. I decided to use RCA for the outputs, as it's easy to get and accomodates the lines nicely. It didn't hurt that I had a bunch of RCAs laying around the house either.

I made a couple extension cords as well. This way, I can use one control box for both cannons. I've designed the whole thing to run off of 12v DC, with a pretty low draw. Although the relays draw 6w when engaged; they aren't engaged for very long continuously. I usually run the system off 8 AA batteries. It's a small pack that's very easy to conceal. Conceivably, I could run the cannons from a compresses cylinder (to hide the air lines); but I'm not sure that's necessary.

I'm planning on making some special gravestones with remote-controlled popping heads. I just haven't gotten to that part yet. I think they will be air-powered also.