Two years ago for Halloween I had a mask made for a costume which, while a lot of fun, made it hard to interact with people at Halloween parties. Last year I wanted something that wouldn't require me to wear anything special and I hit on the idea of a ventriloquist dummy.
I'm not any good at ventriloquism so I thought it would be easier to bring him to life than me learn how to throw my voice. Rather than re-invent the wheel I thought it'd be better to find a toy that already did what I wanted and use those mechanics to bring my dummy to life.
Here is what I did and how I did it. I didn't track the time but it took about 3 weeks of a few hours here and there and a lot of trial and error. In the end I didn't actually need to re-wire anything and the guts of the toy would have enabled even more actions if the dummy supported it.
Step 1: Obtain Your Dummy and Pre-made Animtronics
I found this "Deady Bear" at a Spirit Halloween store. The bear does a couple of things, it moves it head back and forth, tilted its head, has an articulated arm motion and flaps it's mouth, so I have 4 movements to work with.
The dummy has a hollow body and a large cavity in the middle. The head is controlled buy a single post in the middle with a trigger mechanism that operates the mouth. That's all that moves, the eyes and eyebrows are painted on. The picture doesn't show it but the control stick has a hook on the bottom through which an elastic runs to a plastic plug in the butt of the doll. This keeps the head firmly planted on the body but allows it to move around when you're controlling it. There is another elastic string up the control stick to the mouth to keep it closed. Pulling on the trigger forces the mouth open and the elastic pushes it closed. This became important later, as you'll see.
Step 2: Tear Apart Your New Toys
This was basically carefully opening the Deady Bear to make sure I didn't cut any wires. There is a battery pack in bottom with the circuit board on top (white) which is glued to a little speaker cabinet (black). On top of that is the motor assembly (brown). The base has the arm articulator and above that site the head piece including the mouth flapper.
The head was an entirely separate piece so I did that next. There are two electronics in the head piece 1) the mouth "flapper" and 2) the LED eye. The flapper is glued to the top of the assembly and the wires run right down the center. For some reason the LED power starts at the center then came up the back of the head and then over the top to the eye. When i cut the head open i snipped those wires, as you can see in the picture. This was not intentional. The LED was tiny anyway so I wasn't going to use it, but I would have liked the option.
Step 3: Get the Guts
Now that I've disassembled the bear I need to strip it down. I don't actually want the noise it makes so I cracked open the speaker cabinet and cut the wires to the speakers. The white wires and button to the right are the "demo" button. The bear is sound activated but you can start up the sequence with this, which came in handy later.
There is some extra housing around the lower motor and arm and assembly, I took that apart in the last photo (with the dummy looking on). There was some fabric covering everything, I assume to stop the stuffing from getting in the joints, but my dummy isn't very fluffy so that won't be a problem.
The battery pack has the circuit board on top and since I'm really using it as-is I just need to be careful I don't cut any important wires, otherwise it's all staying the same. Copious amounts of duct tape will help me do that later.
Step 4: Take a Break
Watch a movie
Step 5: Wire 'em Up
So now I have three distinct pieces I need to finagle:the battery pack/circuit board, the motor and the mouth flapper. The simplest one is the flapper, it has enough force to push the mouth trigger on the dummy so I used a zip-tie to attach that.
Next I have to get the motor in the body cavity and able to move the head. It fit fairly easily and I used a combination of zip-ties and a small metal rod to attach the motor and the control stick. There wasn't a lot of hard points on the motor I could mount things, and the motor used a rotating force which sheered any glue off so I tied the metal piece to the control stick, then created loops on the motor and threaded it through there. This also gave me the ability to take things in and out as needed.
Normally the elastic would keep the head attached to the body. I had to remove that to fit the motor in, but the weight of the motor did well enough on its own. The problem now is that the motor is hanging freely from the control stick and when it ran the mouth moved but that was it.
Step 6: Make It Move
I said earlier the head was connected to a plug in the bottom. I ended up ripping this plug out to fit the motor in (it stuck too far up into the body cavity). Now the motor is swinging freely and the head isn't moving. I used a pair of zip ties round the base of the motor and fed them out the bottom. I ran one up the front and the other out the back and taped them to the torso. Now the motor stays put and the head moves.
In the videos I've been pushing a small white "demo" button that came with the unit. This can also work as sound-activated. I ended up using both, the sound activated was good when it wasn't too loud but during a halloween party it wouldn't stop going off, so I set it to on-demand only.
Some minor adjustment is needed to get it looking good, but he's finished!