Sliiiiiiiiiiiinky - the world's longest Slinky??

2006 July 6:

Added some notes on how to find what I call 'shirring elastic'.

2006 April 4:

Added some photos 1, 2, 3 of a 20 foot Super Slinky made by some students in Tucson Arizona.  This is the work of Erik and colleagues who have a bus dedicated to hands-on physics exploration: http://www.physicsfactory.org .

2002 April 14:

• Added Real Video files to the video/ directory.
  
• Added extensive stereo piezo pickup sound recordings in the audio/ directory.
• Added some photos from the 6 April 2002 outing, taken by Hugh McSpedden.
  

2002 February 10:  

• Someone mentioned Sliiiiiiiiinky at the global geek hangout slashdot.org and a lively discussion ensued.  Instead of a few hundred accesses per month to this page, there were about 55,000 in a day or two, plus 11,000 accesses to the page showing the Space Cadets  following them receiving an honourable mention in dispatches.   
• I added some audio samples and spectrum analysis charts in the audio/ directory.  The samples are from a piezo pickup and include wind whistling eerily and what may well be the longest chirp in any physical system.
• Sliiiiiiiiiiinky may be wriggling in Melbourne in late March or early April, so write to me at rw@firstpr.com.au if you would like to come.   

2000 May 10: 

• Running Press have published a book by Lou Harry on the history of the Slinky, with the above picture and some text describing Sliiiiiiiiiiiiinkyas "The Ultimate Slinky".  It is a small, beautifully designed, well bound 80 page, well illustrated, hard-cover book and comes in a presentation package with a steel Slinkyall ready to walk and wriggle.  The book will be available from:  http://www.runningpress.com/.  There is also a miniature version of this book with a Slinky Jr (32mm high, 42mm wide 72 turns). 

14 November 1999  (Page established 5 January 1999.)

Here are photos and a description of my long 21 metre (71 foot) Slinky.   Richard James invented the Slinky in 1945, and his family still run James Industries, employing over a hundred people manufacturing Slinkies.  (Slinkyis/was a trademark of James Industries Inc. Pennsylvania, which was purchased in 1998 by Poof Products, Michigan.)  On 12 November I spoke to Tom James, CEO of James Industries, and he told me he was unaware of any otherSlinkiesof this length.

These photos are from 31 December 1998 at Beckett Park, in the Melbourne suburb of Balwyn, and 1 January 1999 at the Earthcoredance-party at Goughs Bay on Eildon Weir.  (See the map here - it is south-south-west of Mansfield in the top corner of the map.)

In the future, I intend to have videos and details of how I made this, so that others can construct their own.

On 13 of November 1999 I put the Sliiiiiiiiiiinky up again at Beckett Park. (Here is the invitation.) 

Click on the small photos to see the full-size version.  Each large image is between 34 and 165 kbytes. With Microsoft Internet Explorer, you may have to wait for the entire image to load before you see anything.  One more reason to get the better browser - NetscapeNavigator or Communicator - where you see the image loading progressively.
 

Back to the main First Principles index page for all sorts of show-and-tell things.

  <<<< Click on the photos!!!!

I decided to make Sliiiiiiiiinky on my 43rd birthday in early November.  I hadn't done anything aesthetically creative since making some music with Csound in 1996.  I could have earned some more money, but instead I thought of a really fun thing do do with it!  There's much more to Slinkies than walking down steps!  For instance, let one hang to the ground, supported by the last two turns resting near the tip of your little finger.  Now stick your little finger in your ear and touch the Slinky with a coin.

The primary purpose of Sliiiiiiiiiiiiiiiiinky is to send large low-frequency waves which are visible rather than audible - waves in the 0.2 to 10 Hz range.  The audio-frequency vibrations are intriguing too - I have experimented with a piezo pickup.  See the audio/ directory .   A few people looked quite perplexed and asked me, very seriously, whether it was art.  Whether people consider this art or not, I don't mind.  I see a lot of art in many everyday things people do.  Kinetic Sculptureit certainly is!  Or rather, kinetic sculpture is what people dowith it. (See the end of this page for Kinetic Sculpture links.) 

The first photo was taken at lunchtime Thursday 31 December 1998 - after I finished construction the night before.  Lachlan Hardy at this end, sending some handsome waves west.  Lachlan helped me construct Sliiiiiiiiinky.   See here for a fab short essay by Lachlan on adventure. My father Jeff is at the other end.  To the right is my mother Ruth and my youngest brother Matthew- who helped me set up and run Sliiiiiiinky at Earthcore that night.  When I was growing up my father was a research physicist.  My parents were able to answer almost every question I ever had and I have been very lucky to have such an upbringing!  Hoorah for energetic, loving parents - and for Mechano and Encyclopedia Britannica. (Now, if we only had the Net in the 1960s . . . ).
 

Sliiiiiiiiiiiiiiiiinky Staaaaaaaaaaatistics:

• 34 Slinkies soldered together.  They are zinc-plated spring steel, and are very easy to solder. There is actually about 33 and a half of them.
• 418 fine elastic supports, of "shirring" elastic.  This is 0.7 mm thick and very stretchy.  Each elastic supports 7 turns of Slinky which is about 19.2 grams.
• Tying the knots and sealing them with nail varnish took about a day.  Measuring the elastics took two days - more on how to do this later, it is a difficult engineering problem.
• The frame is made of 25 mm square aluminium tube (aluminum to folks in the US!) which can be purchased already anodized black. (Anodizing is a thick coat of the ceramic aluminium oxide, which in this case has been dyed black.)
• There are 9 sets of legs and 8 horizontal spars.  The legs just fit inside my Kombi and are 3.8 metres long.
• Total length of the frame and Sliiiiiiiiiiinky is 21.73 metres = 71 feet 3 inches = 23.75 yards.
• There are about 2933 turns, constituting about 645 metres of wire = 2,116 feet.
• Each turn is 7.5 mm (0.3") apart - so the spring is not under much tension.
• Propagation speed of waves in the 0.2 to 5 Hz range is walking pace - it takes 18 to 20 seconds to reach the other end.  This may be different for the three different modes: horizontal, vertical and longitudinal.  Shorter wavelengths travel visibly faster.  (This is true of audio waves too!  See the audio/ directory )
• Attenuation is more than I had hoped.  Longitudinal waves are only visible for ten seconds or so.  Vertical waves transform themselves in terms of shape and polarity, and little energy makes it to the other end.  Horizontal waves have about 30 to 40% of their amplitude (so 9 to 16% of their energy) after traveling to the other end.  The reason for the vertical attenuation, and some of the horizontal attenuation is that the elastic is not 100% efficient.  It probably returns only 80 or 90% of the energy put into it.
• Resonant frequency in the vertical direction - about 0.43 Hz (one cycle every 2.3 seconds or so).
• Resonant frequency in the horizontal and longitudinal direction, resulting from pendulum motion - about 0.33 Hz (one cycle every 3 seconds or so).
• Maximum wave size:
• Horizontal: plus or minus a metre at least!  It becomes attenuated after a few seconds to about half of this.
• Vertical: plus or minus about 0.7 metres.
• Longitudinal: maybe plus or minus 0.5 metres.
• Worst problem: tangling and twisting of the elastics around the Sliiiiiiiinky when there are vigourous waves made with it.  The worst tangle was one which was so impossible to resolve that I amputated about 10% of theSliiiiiiiiinky  and later untied all the elastics of that section and retied them. I found the best way to ensure that it is not tangled is to 100% supervision and to ensure the person holds the Sliiiiiiiiiiinky with both hands at once and do not place their hands above their head.  This stops them doing a forward throwing motion which is what causes the trouble

Here is a photo of a large low-frequency vertical wave.  What these pictures don't convey is the slow, graceful, fluid motion of these waves.
By walking alongside them, you can watch them progress and slowly be transformed by the filtering and non-linear effects of the system.  If there are waves coming from the other direction the two sets of wave pass through each other, and the Sliiiiiinky assumes the shape of the sum of them.  This is particularly interesting with standing waves at the other end - as a continuous frequency, or slowly changing frequency, is reflected from the far end.

The differing colours which sections of the Sliiiiiiiiiiinkyassumes are partly due to variations in the zinc plating of individual componentSlinkies. This is particularly so in diffuse, early morning, light.

Co-pilot Adriana Hardy as at the west end, sending waves to brother Lachlan at the east (lookout tower) end.
As I hoped and as several people have remarked, virtually anyone can do something with the Sliiiiiiiiinky and it will be visible to themselves and others.  Perhaps only paraplegics cannot create public kinetic sculpture with it.

There are a wide variety of things which can be done with the system.  There are limits beyond which the elastics will become tangled - mainly longitudinal waves caused by "throwing" the end.  One part gets ahead of and on top of another, and all hell breaks loose!  Many are things I would never have thought of, and it is a special pleasure seeing people come up with novel and often delicate ideas for how to make Sliiiiiiiiiiinkywriggle or writhe.

It is good therapy.

Other than water waves, I think that most people have little awareness of the nature of wave motion - and water waves are a very specialised and cryptic form of wave motion.  Sound is the most common, obvious, wave motion we encounter.  I am often seeing audio as waveforms and I generally understand the processes which cause sound, so waves are an ordinary part of my life.  Still, it is a pleasure to see them so large and slow and pure!

Light is waves of the electrical and magnetic fields. It is identical to radio-waves, microwaves, infra-red, ultraviolet, X-rays and gamma-rays - except that these have longer and shorter wavelengths.  The only thing which keeps electrons in orbit around atoms is the same stuff: photons of electromagnetic waves.  So every chemical bond and all the forces which hold us together are also based on waves. (The forces inside the nucleus of atoms is a different story!)

Co-pilot Adriana sending more waves to Lachlan.

These move gracefully, but when there are substantial waves of different frequencies going in both directions, the result can be quite complex.  You can see some of Adriana's paintings in the gallery section of this web site.

If I was going to build another one, I would be tempted to use black shirring elastic instead to make it less visible, especially at night.  After these photos were taken, I dyed the elastic a mid grey, and I think it is less obtrusive this way, though many people like the waves in the white elastics too.

Sliiiiiiiiiiiiiiiinky is having a rest.

I was concerned about getting all the elastics exactly the same length, but it doesn't matter if they vary somewhat, since Sliiiiiiiiinkyis rarely sleeping when anyone is around.

Remember, these photos are "thumbnails".  Be sure to click on each photo to see the full-size image!

Because it was only me, most of the time, looking after Sliiiiiiinky and there were thousands of enthusiastic people, I decided to fence off all but one end.  The yellow tape is "Acid Hazard" industrial warning tape someone gave me because of my Devil Fish work with the TB-303 "acid" box beloved of many techno musicians.  It generally worked, but I did have to talk to a few people.  One excellent idea was to lie on the ground underneath Sliiiiiiiiiiiinky and watch the waves go right over you.  I want to try this sometime, but I didn't want people doing it this night, because it is so easy to bend the Sliiiiiiiiiiiinky and tangle the elastics.

The Sliiiiiiinky was set up in a gentle valley between the three sound-systems.  There wasn't time to organise lighting, so we used a 12 volt hand-held spot lamp running from the Kombi's auxiliary battery.

At the far end, I placed a ladder and some masking tape to keep people out.  This isn't very aesthetic.  The last two sections of the frame are going up the side of the valley a little and this was excellent because the people at this end who were making the waves could see the far end clearly - where their efforts took 18 to 20 seconds to arrive.  The far end was held by a light elastic to the ladder, so it was effectively free to move.  This caused waves approaching the end to be reflected, so if a continuous frequency is sent for 20 seconds or so, in the absence of other waves, then the far end develops standing waves because the amplitude of the waves going to that end and being reflected from that end are about the same.  It is a very attractive movement - like a snake!

The first photo shows the results of some fast wrist-shaking, with one big left-right-and-back-again swing in the midst of it.

The second shows the results of circular arm movements.  It is great fun making a tubular, revolving, moving-away spiral like this! Unfortunately, it also causes Sliiiiiiiiiiiiinky to twist and roll over, causing serious tangling.  Minding Sliiiiiiiiky can involve encouraging people to be demonstrative with it, but also warning them against going beyond the limits of safe operation and towards the tangle zone.

Two reasonably wild sets of waves!

Most ravers are quite gentle with Sliiiiiiiinky.  Some were gently touching it to see how small a wave they could make.  There were a few out-of-place bogans and yobbos at the party.  Those who were drunk and larger than life, or for whom every second word was foul.  They enjoyed wriggling Sliiiiiiiiiiiiiinky as much as anyone else, but I had to keep an eye on them because they could easily do a circular motion and push the end forwards at the same time, which causes one part to land on top of another - and so to tangles.

Some wild action, some contemplative gentle wriggles and some more wild action.  The third image is big - 247 kbytes.

In this fabulous On the Move state of Victoria, tourism development is always high on the agenda - and Sliiiiiinky has great potential!  Late at night, two weeks after the New Year's eve party, amid howling dogs and an eerie light, I found a small package on my doorstep with three happy snaps from some visitors from who-knows-where.  Click on the image below to see them all.

Sliiiiiiiinky was operational from 12.30 AM until 11.30 AM.  Thanks to Shannon and the other people who looked after it while I snoozed in the shade of the Mango Mothership!

A special thanks to Cat and Becky for their special help, and to Lachlan and Matthew for their assistance with building and setting it up!

Shannon helped me set up Sliiiiiiinky at Earthcore in February.  I have a few photos of that, but I mainly concentrated on taking videos.  I hope to have some video files on this site before too long, and some notes on how to make your own Sliiiiiiinky and frame.

6 April 2002

"There is another system!" - Colossus, in "The Forbin Project".

Thanks to Jim Gage in Sweden for telling me of a Slinky at a hands-on science "museum" in Copenhagen.  The link to the English version of the web site of Experimentarium, is http://www.experimentarium.dk/. The Slinky page (with a long URL) was here but perhaps this site is changed or kaput.

It is a 15 metre Slinky, although Jim thinks it is a specially made spring rather than an authentic product of James Industries Inc.  It is suspended by strings, so it can support horizontal and longitudinal waves, but not the vertical waves which are possible with the use of elastic suspension.

It is supported from the ceiling and nowhere near the ground - so people cannot tangle and stretch it.  It seems that one or both ends can manipulated by visitors and that a balcony runs alongside it.  I have contemplated a Sliiiiiiinky installation in a building, and this idea of having the balcony run alongside it, but not close enough so people can touch it, seems ideal.

Experimentarium looks absolutely fascinating! A quick browse of the 300 exhibits gives me the impression that its exhibits are generally interactive and that they are finely attuned to an appreciation of the physical world.  Some science museums have too many computer simulation devices, geared more for entertainment than insight, in which all-too-often children simply hammer away at the buttons trying to make something happen, without a care as to what actually happens.
 

Updates

In March 1999 I heard from author Lou Harry who was completing work on a book about the history of the Slinky. He had met Betty James, who in 1998 retired as CEO of James Industries, the company she founded with her husband in 1945 to make Slinkies.  James Industries has been sold to another toy company with a strong belief in US based manufacturing: Poof Products.  (This is a business name which wouldn't last in Australia, because it is a pejorative term for male homosexuality.) Poof's specialty is a wide range of toys made from foam plastic.  Check out the web-site of their Slinky Toy subsidiary - they even have a gold-plated Slinky!

Lou Harry told me he had never seen anything like Sliiiiiiiiiiiiiinky, so perhaps it is the longest Slinky after all. In November 1999, I spoke with Tom James, son of Betty James, who named the Slinky. He said they had never heard of anything comparable to Sliiiiiiiiiiiiiiiiiinky. The next step will be get an entry for the longest Slinky in the Guinness Book of Records!

A note on the spelling of Sliiiiiiiiiiiiiiiinky.  I just hold the "i" key down for as long as I feel like each time.

Elastic

Here are some notes on finding elastic for your Sliiiiiiiiinky project.   Please do let me know of such constructions you make yourself, or any success finding this elastic for sale.

I bought several spools of "shirring elastic" from an industrial supplier M. Recht, as discussed below.  The label inside says "DuPont Lycra Canada", "Decitex 310" and "3226-MERGE 130- 18- 13" (Decitex apparently means grams per 10,000 metres, whereas Denier means grams per 9,000 metres.). 

The term "shirring elastic" does not appear to be used in North America.  This is like hat elastic, but thinner.  There is a single core of white elastic, which is presumably "spandex", also known as "elastane".  "Lycra" is a tradename for "spandex".  It has two sets of fibre wrapped around it, in opposite directions, which are also white.  This fibre is simply wrapped, not woven as it is in "hat elastic".  It is about 0.5mm in diameter.

DuPont's division which made this is now Invista: http://www.invista.com/  but I can't find any detailed product information there or at lycra.com .  Here is a technial page on "lycra yarn": http://www.indiamarkets.com/imo/industry/textiles/textilefea52.asp .  This mentions "310 dtex" Lycra yarn.  "310 dtex" is a good search term:

http://www.kunalintl.com/spandex.php

I still can't advise on anywhere to purchase this in North America.  However, if you contact M. Recht and Company, who I have found to be exceptionally helpful, they can supply it.  Their current shirring elastic is not identical to what I bought from them in 1998, but it is presumably the same thickness and elasticity.  They say it is an 850 metre cone, weighing 0.5kg.  The cost is $11.81 per cone. 

http://www.mrecht.com.au/Products/6.elastic.htm

You may also be able to purchase it from the following sites, which I found with a search for "shirring elastic":

http://www.kleins.co.uk/index.asp?function=DISPLAYPRODUCT&productid=204

http://www.thread.co.uk/elastic.htm  This looks quite promising.

http://www.sewessential.co.uk/Category.asp?CategoryID=457&NumPerPage=5&page=1 Likewise.

http://www.thesewingbee.co.uk/general.html 
   

Some Slinky Links

• Slinky Toys:  http://www.slinkytoys.com/  (previously James Industries) - the home of the Slinky since its invention by Richard James in 1945.  This site lists places where Slinkies can be purchased, but check the next item:
• Where to buy? A good place to buy a full range of metal and plastic Slinkies with quantity discounts and shipping to other countries is Metal Toys in Texas:  http://www.metaltoys.com/Slinky.htm .  In September 2002, authentic James Industries Slinkies were unobtainable in Australia, since no company was distributing them.  
  
• Slinky science: http://www.teachingtools.com/Slinky/slinky.html
• A short treatise on what little is known about the Slinky's inventor, Richard James, after he left his family and business in the care of his wife Betty in 1960, and travelled to Bolivia to pursue religion.
• A Slinky  home page: http://slinky.org/ 
• Arbor Scientific http://www.arborsci.com/Product_Pages/Sound&Waves/Sound&Waves.htm has a variety of devices for exploring wave motion and vibration, including long Slinkies.
• How does Slinky fall?  An illustrated physics treatise:  http://hubcap.clemson.edu/phys-car/fun/slinky/
• A history of the Slinky with a photo of Betty James.  http://www.discovery.com/stories/history/toys/SLINKY/shoulda.html .
• A Slinky page, with a Slinky postage stamp.  http://people.bu.edu/dpelleti/ 
• A well-travelled Slinky: Slinky Around the World http://home.rochester.rr.com/satw/index.html .
  
• Slinky in space!  http://images.jsc.nasa.gov/images/pao/STS51D/10062112.htm  The Space Station is the place for Sliiiiiiiiinky action - then there's no need for all those elastics!
• A large Slinky collection:  http://www.t-smirks.com/slinky/
• Check out these great pages on making reverberation devices using Slinkies:  http://www.electronicpeasant.com/projects/springs/springs.html , http://www.musicsynthesizer.com/DIY/Grant/Spring%20Thing/The%20Spring%20Thing.html and http://www.electronicpeasant.com/projects/thermio/thermio.html .
  

Please email me if you want to know more!  email: rw@firstpr.com.au .

- Robin Whittle

Update history

• 2006: April 4: Added photos of the 20 foot Tucson Arizona Super Slinky.
  
• 2005 April 25: Added links to Electronic Peasant's reverb pages.
  
• 2002 September 10 and 12: Added link to Slinky collection, and to Metal Toys in Texas.
  
• 2002 April 14:  Added videos, stereo sound recordings and more photos - all from the 6 April 2002 outing at Beckett Park.
• 2002 February 10:  Added audio directory and cleaned up links, including removing those on kinetic sculpture.  But for continuity and my own reference I want to retain this set of links to the rolling ball sculptures of George Rhoads:
• David M. MacMillan http://www.msen.com/~lemur/ has some pages on kinetic sculpture, delightful machines & automata etc. and rolling ball sculpture.  This includes material on many rolling ball artists.  There is even a mailing list! The rolling ball section contains extensive information on George Rhoads (sometimes misspelt as George Rhodes), who specializes in audiokinetic rolling ball sculptures - elaborate mechanized sculptures involving balls doing all sorts of things, including striking various things to make sound.    One of his works - Global Circus - from 1985 / 88, is at the Northland shopping centre a few km from where I live, and for years has been delighting young and old for many years. There is a large work of his at the Vancouver Science World.
• 1999 November 14:  Added notes about this being apparently the longestSlinky, about the party on 13 November.
• 1999 March 22: Added material about Lou Harry's book, the sale of James Industries, the Slinky Toys web site and made prominent mention of the need to click the small images to see the full-size versions.
• 1999 January 28: Fixed problem with first three images not being linked to.  Reduced file sizes of all .jpg files.
• 1999 January 15: Added intergalactic tourism snaps and mentioned Sliiiiiiinky will be at Earthcore's Toolangi party.
• 1999 January 11: Added link to 15 metre Slinky at Experimentarium in Copenhagen.
• 1999 January 8: Corrected spelling of George Rhodes to George Rhoads.
• 1999 January 7: Added material on kinetic sculpture.
• 1999 January 5: Page established, with photos from Beckett Park and Earthcore.