Chuck's Slinky Torus Design Challenge

(Note- I'm entering this in the DIY University contest because it's a really fun tactile toy. When you get to college you'll do some experiments. Some will help you understand chemistry or physics and some will help you understand what Pink Floyd is all about. During those latter experiments you will find simple toys like this to be profound in unimaginable ways. Trust me.)

Have you ever created something that was both wonderful and useless?

Let me tell you a secret- I play. I'll sit for hours mesmerized by some arcane hair clip that my wife left on the coffee table, connecting clothes pins in every conceivable way or bending and connecting drinking straws. Having something physical to fidget with seems to aid my creative process. Of course it drives my wife nuts.

I picked up a few Slinky spring toys at the dollar store to use in an audio spring reverb project. I was sitting at my computer reading the news and playing with one when I got the idea to solder a slinky into a loop, like a spiral torus or 'donut' (http://mathworld.wolfram.com/Torus.html ). I envisioned something like a 3D model of what a Spirograph or draws.

I took a Slinky over to my bench and soldered the two ends together. I was immediately absorbed into a twisty, stretchy, wiry world. The properties of the Slinky combined with the properties of the torus to make a shape that was really fun to play with. I took another Slinky and cut it in half to make two smaller donuts. I played with them for a while, being careful to keep them apart so they wouldn't get tangled. Anyone who's ever dealt with a tangled Slinky knows what I'm talking about. The rigidity and springiness make them hard to untangle.

Of course eventually the inevitable happened and i dropped one loop on top of the other. The top loop slowly sank into the bottom one until they seemed to occupy the same space. Uh oh, this was going to be a pain. As I gently lifted the two 'tangled' springs to get a better look at the mess the top loop fell out and landed on my desk. They didn't tangle at all! After a few careful experiments I soon realized that they were actually kind of hard to tangle. I could slip them together and separate them easily or pass one through the other. They could be intersected at different angles to create cool forms, like hyper-dimensional Venn diagrams . Two loops was ten times more fun than one!

Did I mention that they were fun to play with? Everyone I've shown them to can't resist rolling them around in their hands and stretching them out. My cat loves to bat them around and toss them in the air. It's a really fascinating form with interesting structural properties that you can feel. I made my first models over a year ago and I still play with them regularly.

The puzzle is figuring out what to do with it. Aside from making earrings to cosplay Aunty Entity, I can't really think of many practical applications for these Slinky donuts. I know there's an Aha! moment buried in here somewhere. That's why I put up this Instructible. Make a few of these Slinky tori for yourself and see what you can come up with. If you dream up a cool use for them post your own Instructable and let me know. Let's have fun and make something cool!

I used Mini Slinkys which are smaller and thinner. They were $1 each at the local Dollar Tree. The ends of the Slinkys were already soldered closed to prevent kids from coming into contact with the stiff wire so I simply cut the ends off.

I looped the Slinky around and carefully aligned the end rings so that they over lapped for about 30% of the total circumference. Pay attention here because if it's not soldered straight it will look flawed later. When everything was straight I used a small pair of Vice Grips and clamped the wire firmly. I soldered the joint, paying special attention to make the ends smooth. When the joint cooled it checked for sharp edges which I smoothed down with a quick wipe of my iron. I repeated these step with the second Slinky and I was done.

Check out the video and see what I've got so far. What can you do? Spring reverb? Ratcheting clutch for your robot? Weird sculpture? DIY moon buggy tires? Go nuts!

https://vimeo.com/105326887