First, I would like to say that this system was adapted to an already existing coffin and dummy. The coffin is made from discarded paneling with 1x2" wood framing. The frame for the dummy was made from an old floor lamp and tubing from the legs of an old baby swing, a pop bottle for the head. Forearms and hands made from coat hangers and clear plastic tubing and silicone for the knuckles. Had I to do it over again, especially with animation in mind, I would probably use PVC pipe for the dummy frame. Second, there's LOTS of room for improvements and innovation with this idea. I only had a week to work on this project once the idea came to mind, there's definite signs of a rush job in my version.
The drawings depicted on this page are only close approximations and are meant to give you the "general" idea, so please do not take proportions literally. Test fit everything before making the final cut, bend or mounting. The design however does work, and works very well. I only had one failure towards the end of the night and that was the way I had the arms mounted to the shoulders, an "L" bracket, a bolt/nut (to allow turning) and two metal screws into the arms. The metal screws had worked loose. I tightened them up and all was fine. The one area I thought I would have trouble with was the "shoe string" but that held up surprisingly well. (I used the large "flat" braided type from a sneaker / tennis shoe.)
I should mention that I used a small peice of rubber hose, like the type used as vacume lines, or radiator overflow on your automobile to attach the shoe string to the motor shaft. I cut off a piece about 1 inch long, pushed the shoestring through the piece of hose, then pushed it onto the end of the shaft, leaving enough slack in the string for several turns.
What this prop does is; Suddenly lunge forward, opening it's arms as if
attempting to grab the intended victim.
Once the scare has been successful,
he goes back in his box and waits for the next
one to come along.
Another thing I should mention, I put 2 pins under the hairline of the mask to keep it from flying off. One in front and one in back
How it works is this; when the power is applied via a button or whatever triggering device you use, the motor wraps the string around the shaft pulling the "slide" down, which in turn causes the push rod to change from an almost vertical to an almost horizontal position - pushing the dummy outward. Imagine a pair of scissors opened all the way then closing them, same principle. The outward motion also forces the arms to open as the coat hangers in a "criss-cross" arrangement allows for forward movement, but pulls on the "L" brackets mounted on the outer sides of the arms in a pinching movement. My version depends on gravity for the dummy to retract back into the box. I have the coffin tilted back against the house. When the prop is triggered, the dummy stands almost straight up, but not quite. When the button is released, the power is cut, the dummy falls back pushing the slide back up the track, unwinding the motor and folding the arms back up.
The tracks and slide are actually parts from one of those cheap ski type exercisers. I removed one set of tracks and one of the foot mounts then mounted it vertically inside the coffin. I know, not everyone has one of these laying around but the exerciser isn't necessary. Just find something to use for tracks four wheels that fit inside them, 2 axles and a block of wood - there you have it. If you give it some thought, you might even come up with a better idea altogether.
This pretty much concludes the drawing phase. I hope they give you enough
information on how this prop
works.The only thing I'll do at a later date is
to add a page with some actual photos of the thing.
If you have any
questions, e-mail me. bq549@prodigy.net