Animated Halloween Display Using an Electric Motor and a Bicycle

Here is a way to make an animated Halloween display, using mostly things you already have around the house.  I powered the display using a small electric motor hooked up to the back wheel of my bicycle, and strings attached to the pedals pulled the arms and legs of the life-size dummies.  It has plenty of power to move several large dummies.  Check out the videos to see the display in action!  The whole thing took me about 4 weekends to prepare.  I am publishing this well in advance of Halloween so you have time to collect your materials and prepare everything.

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Step 1: Materials Needed

Here are the materials I used:
1 bicycle.  A 10-speed bicycle is best, so you can adjust the operating speed.
1 small electric motor.  The one I used came from an 8" floppy disk drive (if you know what that is, don't tell anyone, it means you are very old).  Any small motor from a power tool, fan, etc. will do.
Assorted scraps of wood.  Some pieces of 2x4, 1x2, MDF (counter-top material), and plywood or pressboard is what I used.  Whatever you have.  I had to buy the 1x2, but they are very cheap, about $1 for an 8' length. 
Several small hinges.  I had to buy about a dozen of these, $1.69 each at my local hardware store, plus I re-used two old cabinet door hinges. 
Fishing line.  I used the 40lb test, the thickest.  Bargain brand was $3.99 for a big spool.
Small pulleys.  I bought 8 of these, about $2 each at my local hardware store.
Bubble wrap.  To stuff the dummies.  Bubble wrap is better than newspaper or other stuffing materials because it is waterproof (in case it rains on Halloween).  You will need a lot, so it may take some time to collect enough.  Please don't buy it, it is expensive, and people throw away tons of it every day.  Think green!
Packing tape.  To hold the bubble wrap in place.
Yellow "Danger" tape.  To keep trick-or-treaters from getting tangled up in the fishing line, or messing with the dummies.   You can buy it with a Halloween themed message in October.
Wood screws.  Obviously.

Other materials which you may or may not need depending on your theme and your setup:
Black paint.  For the base.
Shelf Bracket.  I used this to hold Michael's foot in a tip-toe "Moonwalk" position.
Lawn plant hangers.  I used 3 of these to support pulleys for lifting the dummy arms.
Tent pegs.  For attaching support lines to hold the plant hangers vertical.
Halloween masks, wigs, gloves, etc.  For the dummies.  Most of what I used came from a big box of Halloween costumes I got at a garage sale.
Old clothing. What you need depends on what your theme is. In my case, Michael Jackson needed a red jacket, red pants, some black trim for the jacket, black shoes, white socks, and a white sequined glove.
Plus other assorted bits of hardware, metal brackets, cable ties, screw hooks, etc.

Step 2: The Dummies

Unfortunately I didn't take many pictures while I was building this display, I wasn't planning to make an Instructable out of it.  But I think there are enough pictures to show how it is done.  I'm sure yours will be different anyway depending on your theme and your materials on hand.  My theme was Michael Jackson's Thriller video, which was great last year but maybe not as appropriate this year.  (Apologies to MJ fans who may think my display is disrespectful.)

I found a 2 foot square, 2 inch thick piece of MDF (counter-top material) in a scrap pile, very heavy, to use for Michael's base.  I don't know where you would buy something like that, but you can make a base from 2x4's, or just use the regular 1" thick MDF.  I spray painted it black before starting to build. 

Michael's right leg is made from 2x4's, very solid because it is holding the entire weight of the dummy.  A shelf bracket is mounted on the base, it goes through a hole in the sole of the shoe and attaches to the 'shin' 2x4 which has the end cut at 45 degrees.  I did it this way because Michael was to be in a 'tiptoe' Moonwalk pose.  First I made the wooden core of the leg, then I put on the sock and attached the shelf bracket to the leg, then I slipped the shoe over the shelf bracket onto the foot, and finally attached the shelf bracket to the base.  I had to add extra wood braces to solidify the leg, see the picture.  A "hip" platform (cut in an oval shape from plywood with a jigsaw) is screwed to the top of the right leg, and the left leg attaches with a hinge to the "hip".  The left leg is made from 1x2, to be much lighter, and also has hinges at the knee and ankle.  The legs are wrapped with bubble wrap to fill them out to normal leg proportions, then the pants were put on, starting by putting the right pant leg hole over the left foot.  A small wooden "foot" is inside the shoe, the left sock is put on and the shoe is screwed to the foot through the sole. 

The dummy torso frame was then made on top of the hip platform.  The head was attached to the "shoulder" platform.  Later, the arms (1x2's with elbow hinges) were attached to the shoulders.  The torso and arms were stuffed with bubble wrap and dressed.  My wife attached some black trim to a red jacket to look like Michael's Thriller jacket.

The other two dummies I had in my display were made in a similar fashion, but because they are Zombies crawling out of the ground, they are only torsos with no legs.

Step 3: The Bicycle Mechanism

You need to build a stand to hold the bicycle upright, with the back wheel resting on the motor shaft.  I found a big piece of MDF (counter-top material) in a scrap pile, with this the bicycle stand was easy to make.  You could also make the base from 2x4's.

First make a vertical support 4 feet tall using 2x4, to hold the bicycle front forks and the levers.  Attach it securely to the base, I used two #8x3" screws through the bottom of the base, plus I attached a small brace 1 foot long at 45 degrees to hold the support vertical.  Be sure that any screws underneath are counter-sunk so that the heads will not scratch the floor.

A horizontal bar at the top of the support is for attaching the levers.  Cut 4 levers from 1x2 or similar, long enough to almost reach the base.  Drill a few holes at the bottom end for attaching strings.  Attach them to the support with hinges, two on the left and two on the right side of the bicycle, a few inches apart so they won't hit each other.  Put a stop at the bottom so the levers can't go too far forward. 
I made this lever arrangement because I wanted to be able to adjust the amount of motion, by attaching the fishing lines to different points along the length of the levers.  But in the end I only used the bottom holes on the levers.  So maybe I could have made the setup without the levers.  I think it would be better to have the levers swing a little farther forward than what I did here, then the motion would transfer more efficiently to the fishing lines.

Drill a hole sideways (the 4" direction) through the 2x4, about 14" above the floor (for 27" bicycle).  Remove the bicycle front wheel and the front mudguard and use a long bolt and some washers to attach the bicycle front forks to the support.

Attach a vertical support that touches the bicycle frame near the back wheel.  This is to keep the bicycle aligned on the motor shaft.

Attach the motor to the base, so that the rear tire of the bicycle rests on the motor shaft.  I used two 90 degree metal brackets to hold the motor.  Make sure that you mount the motor so that the bicycle wheel turns BACKWARDS when the motor is running, otherwise the pedals will not turn!  You will have to adjust the angle of the motor shaft so that the bicycle presses slightly against the rear support when running.  To do this, loosen the screws holding the motor to the base and rotate it slightly, then re-tighten.

Tie strings between the bicycle pedals and one lever on each side.  Don't use fishing line for this, use something heavier, there will be a lot of force once all the dummies are hooked up.  Attach pulleys to the base under the pedals, and tie more strings between the pedals and the other two levers, through the pulleys.  The idea here is you will have two independent sets of levers, so all of the dummy movements are not perfectly synchronized.  This makes the display look a little more interesting.

Attach a horizontal bar to the front of the support, in front of the handlebars, high enough to reach out the window.  Attach 3 screw hooks in a line close together (1" separation) on each side of the horizontal bar.  These hooks are under the curtain in my picture, so you can't see them.  Arrange them so that the opening on one is up, the next one down, the next one up.  When setting up, you will thread the fishing line through the screw eyes.  This will guide the lines through the window without touching the window frame.  The advantage of screw hooks over pulleys is you will not have to disconnect the ends of the lines to thread them through the hooks.

See the notes in the pictures for more details.

Step 4: Setup

Once you have everything built and ready, you can set everything up in the afternoon Halloween day.  Fortunately Halloween was a Saturday last year, so I had all day to prepare.  It took me about 3 hours to get everything set up and working.

Set the dummies in place.  The torso dummies I weighed down with bricks so they wouldn't tip over.  Attach fishing lines to the moving parts of the dummies, and run the fishing lines through the open window to the bicycle mechanism inside.  Thread the lines through the screw hooks and attach them to the levers.  You will attach a left arm to a left lever, and a right arm to a right lever.  Use different levers for different dummies, so they are not all moving their hands in the same direction at the same time.  (or maybe you want all your dummies moving together, if they are line-dancing or something)  Turn on the motor and check that everything works!  You can change gears on the bicycle to speed up or slow down the motions.

See the notes in the picture for more details.

To add some flair to the display, I connected three colored floodlights to a 'color organ' circuit to flash in time with the music ("Thriller", of course), which was playing through a stereo speaker in the open window.  Plus I had my "lightning" display that I made from old camera flashes... but that will be another Instructable...