This is a Collaboration between MakerBlock and I for the MakerBot United Competition. And we now have a new collaborator syvwlch! If you like it, please click the 'like' button!
These are a set of Windup ChatterBox Teeth, like the kind you get in gag stores or the kind "The Joker" always seems to have in "Batman". The two toned teeth are of course achieved by changing the filament at the proper time during the print. The wind-up portion is driven by a clock spring, which you can get from any old wind-up toy (or a wind-up clock, but why would you want to destroy a clock?). I got this particular clock spring from a Dollar Store Easter Toy, you can see the pictures of the Harley Riding Easter Bunny I sacrificed in the instructions.
The Drive Mechanism is a Geneva Drive, which is pretty common for a wind-up toy. You wind up the spring and it rotates a cam shaft, opening and closing the teeth. Unfortunately, we could never get the mechanism to work properly. The teeth chatter of course, but the problem here is they chatter too fast and the clock spring expends its energy WAY too fast. We still have a few days left in the competition, so if anyone thinks they have a solution for this and would like to collaborate, speak up now!
We have tried every thing we can think of and are at our wits end. We thought gears would produce enough friction to slow the clock spring down, but they don't!
Print a Bottom Teeth and a Top Teeth. With the teeth, it is best to start with red ABS and then change it to natural ABS right when the gum line ends and the teeth begin of course. Then print the first geneva drive file listed (the other one is a previous version). Finally print, Gear 1 and Gear 2.
Now, the clock spring can be gotten in the toy section of your dollar store. If you want a strong clock spring, go for a toy that is heavier in weight and is meant to roll across the ground. The lighter the toy and the less it does, the weaker the spring will be, so make a GOOD selection! Be careful when you break the toy to get the clock spring out, when you break the clock-springs' case open, it tends to go flying all over the place and may cut you.
Next, you can follow the pictures on the left for assembly of the Geneva Drive. I know, the pictures are slightly different from what you printed, but it should be pretty easy to figure out. Gear Number 2 does not get assembled with the geneva drive yet. So, the only real difference is, the wheel with the axle is now a Toothed gear with an axle. Oh, and the nut that gets sunken into the wheel in the picture. That will go on gear number 2, so you can forget that step. Once you get the spring through the axle, make sure you bend it over on itself, you don't want it to come loose, because then you will have to take the whole assembly apart to fix it. Once you bolt the clock spring case together, just rotate the key to get the spring in there. DON'T FORGET to bend the other side of the spring before it slips into the spring's housing! Next you can bolt it to the bottom of the teeth. When the teeth are together, they should be able to open and close by gravity alone, if they do not... ream out the holes on the top teeth a little at the hinge. All fasteners are M3 sized. I use M3 x 12mm for the hinges and M3 x 20mm for the gears and geneva drive.
The pictures were taken from the older version, but I really wanted to get this out there and there is no time to take new ones yet.
Openscad files for the gears here: http://www.thingiverse.com/thing:8144 and the new experimental gearbox is here: http://www.thingiverse.com/thing:8148
I will upload them to this thing in a little while!