Home Chapter 15 Springs , monofiliment and trick kite string
Springs , monofiliment and trick kite string

Springs are wonderful devices that can store and release energy, act as shocks, and return objects back to a starting place. However, it can sometimes be difficult to find just the right spring with the proper springiness. You can order custom springs with exacting specifications but you must order them in bulk (which can be expensive) and far in advance, because it might take the manufacturer some time to make them. Springs are available in steel and plastic, and a good source is your local hardware store or the larger home builder stores.


Compression and torsion springs


Torsion Springs

Torsion springs are used to hold levers open or closed, and you are probably most familiar with torsion springs from doors that automatically swing shut after you enter. These types of springs would be located at the point of the hinge.


Varieties of springs


Compression Springs

Compression springs are used to provide cushioning in systems or to push on an object that needs to have something engaged. The shocks in your car or on railroad cars are compression springs. The pogo stick you probably hopped on as a child has a compression spring.



Below is a 3D render of how to use a spring to create a universal joint. You simply drill into the two ends of a piece of one-inch bass wood and insert the ends of a spring into each hole. The stiffness of the spring can be adjusted to create different characteristics in the bendable joint. Control or sensor wires can be run through the center of the spring and can extend through your sculpture. Be aware that where wires come through the spring near the end there are sharp edges that can wear the sheathing away from the swire.


Universal joint                                        



This same method can be used to create some pull-string mechanics, whereby pulling on one string in relation to the others will cause the spring to flex. This method was the basis for the joints of Autopoiesis (Chapter 1).


Universal joints with monofiliment to bend



Trick Kite String

Trick kite string is a monofilament (a single, untwisted, continuous strand of manmade fiber) and is an excellent choice for making pull-string mechanics as it stretches very little over time, though it is quite expensive.

Fishing Line

Fishing line is another great choice for any pull-string mechanics. Parts for fishing rods can also be used as guides, though they tend to be expensive, but you can also use Teflon tubing or wood. Fishing line comes in a variety of strengths, and its drawback is that it stretches more easily.