Collapsible sculpture

Question

Question:

I want to make a human-shaped sculpture, that will have string or rope coming out of it and that string will be tied to something, which will make that string tight and keep the sculpture in one piece. But when I cut the string, the sculpture will collapse. Ideally, the sculpture would be lifesized, could be smaller, but at least 1 meter high. It is not necessary to be able to reassemble the sculpture after it collapses.

Other thoughts:

These are the toys from which I got the idea: https://www.youtube.com/watch?v=7bnoQUf6znE, but the difference would be that I want to cut the string.

So I am thinking about which material, in my amateur home workshop, could I use. First I thought about wood, but then I thought that would be too heavy and expensive and hard to work with to make a human shape. Then I thought about plaster, but I am worried it might shatter when the sculpture collapses and it would leave a mess. I am now thinking of paper mache around some wires.

Also, I am thinking if this idea makes sense at all :) so if you have some tips, I am grateful to hear them.

A bonus would be if the torso would be hollow so that I could put another sculpture inside the big one so that it would fall out when the big sculpture falls apart.

Answer 1

If you want to use the same mechanism as in the linked video, the key to that is small diameter rigid tubes with just enough clearance for the string/rope. When the string is tight, it pulls the tubes together and aligns them to make a rigid structure. When the string is loose, the weight and imbalance of the sections causes it to collapse to the extent allowed by the slack string (if the string is cut, it will completely collapse as long as the tubes don't naturally stack into a balanced, stable structure, and the string can freely slide inside the tubes).

You can make the frame/mechanism out of small diameter rigid PVC pipe or tubing. Build up the exterior with any suitable material, like paper mache. Just keep the "joints" free to move. For example, make the ends of the sculpted sections curved so the sections don't rest on each other in a stable way; only the tubing skeleton should have square ends so the pieces are stable when the string is tight.

Your idea with the torso hiding something else that falls out will be hard to do unless you have two independent control strings, and you release the torso first. The structure strings will need to be tight, and will be under a lot of tension. The sculpture will start to collapse as soon as that tension is released, so whatever is holding the torso closed would need to be released first.

You could do something like securing the sculpture strings with a release knot; separate strings in each leg could be tied to a common line that secures the sculpture upright. Pulling another string would release the torso contents, then pull the release knot. In practice, though, it will take a lot of force to release a knot under the kind of stress keeping the sculpture erect.

Answer 2

I'd look at paper lanterns and lampshades.

A classic paper lantern (as shown below) is simply a set of wire or bamboo rings glued to lightweight paper and arranged to create a sphere (oblong, rectangle) form when opened up. They don't self-support at all; I chose the specific photo below to show the inner wire frame holding the structure open. When that structure is removed, the lantern collapses back into a flat disk.

A similar construction is this floor lamp with a paper shade from Ikea (discontinued); The lampshade is a spiral of wire covered in lightweight paper that is held open by gravity; the lamp frame extends to the top where the shade is fixed in place and allowed to fall open to cover the frame and bulb. If the shade is disconnected from the frame, it will collapse down to a flat disk, similar to the paper lantern.

Answer 3

I think you are looking for a collapsible Transformer.

You can get inspiration from a Cubebot

Cubebot® is a wooden toy robot inspired by Japanese Shinto Kumi-ki puzzles. Made from wood and elastic, Cubebot can be positioned to hold dozens of poses. When it's time to rest, Cubebot folds back into a perfect cube.

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Something like this is easily achievable in cardboard.