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Working Wind-Up Answered

I'd like to build a manually operated wind up key( the kind where the key turns slowly) for my costume. One problem; I don't understand the mechanism too well. If you could break down how it works as well as the parts that I would need to create such a device would be greatly appreciated.(P.S. I'm pretty new to this so if you could take that into consideration that would be great too).

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Jack A Lopez

8 weeks ago

Stupid question: Is the scale of this, what you call, "manually operated wind up key" desired to be much larger than a typical clockwork mechanism?

I mean for a typical clockwork mechanism, like found in a mechanical kitchen timer, or Sankyo (r) brand music box, the outer dimensions of the whole package, are usually not more than about 5 cm, with the diameter of the key about 2 cm.

However, when I ask the Instructables Let's make search to show me "wind-up mechanism"

I notice at least 2 of these (by authors chezlin and Carleyy)

https://www.instructables.com/id/Windable-Wind-Up-...

https://www.instructables.com/id/Wind-Up-Doll-Cost...

are for a costume, and these have been scaled up by, probably a factor of about 10 or 15, so that 2 cm key now has a diameter of roughly 20 cm to 30 cm.

The sad thing is, when looking into the details of both of these, the actual clockwork mechanism is some tiny thing that was removed from an actual clockwork toy, so there is this problem of attaching a key that is hugely larger than the actual clockwork.


So I think there is a big opportunity here. I mean, why not build some clockwork that is actually scaled to the size of the key, and the size of the costume? Why has no one done this? Perhaps because no one, or no one here at Instructables, has yet found the courage, or the technical acumen, needed to do this.

Or maybe everyone is wondering: Where do I find a mainspring that big?

In response to your request that I might explain, "how it works as well as the parts that I would need to create such a device", I have already mentioned the main part, which is the mainspring. That is the part the key is connected to directly. The act of turning the key, tightens the mainspring, and puts energy into it. There is a Wikipedia page for this mechanism

https://en.wikipedia.org/wiki/Mainspring

The tricky part is getting the getting the mainspring to unwind slowly.

The Sankyo (r) music box does this with a train of gears, with each gear turning faster than the one driving it. The final gear in this train, is this little fan like thing, whose blades beat against the air, and this provides friction to limit the speed of the whole mechanism.

A typical mechanical kitchen timer, uses a mechanism called an escapement, coupled to another coiled spring with mass on it. Actually that pair of mass plus spring together is resonant. It tends to oscillate at a particular frequency, and it is frequency that determines how fast the timer, "ticks." So it can actually measure time, with crude acuracy.

As an aside: a swinging pendulum is resonant too, but pendulums only work for stationary clocks, because the bearings holding the pendulum have to stay fixed with respect to the direction of up (or down) as defined by the local pull of gravity. A pendulum clock will usually not work on platform that is constantly moving around, like in a wristwatch.

Did I mention that Wikipedia also has articles for "Clockwork" and "Escapement"? Because it does, here:

https://en.wikipedia.org/wiki/Clockwork

https://en.wikipedia.org/wiki/Escapement

Also Downunder35m is giving you some good advice in suggesting you actually examine the inner workings of a mechanical kitchen timer, or music box, as this can maybe give you some insight. It is not coincidence that the Wikipedia article for "Clockwork" also has pictures of these same artifacts; i.e. a kitchen timer and a Sankyo (r) music box, as these are typical, ubiquitous examples of clockwork found everyday life.


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Downunder35m

8 weeks ago

Buy some cheap egg time and take it apart ;)
Should give you all the clues you need, if not check these old "music boxes".
You know, the ones you crank up and tiny metal strips play a melody coming from spikes on a rotating drum.
The first slows down mechanical, the other one with a rotating air break....