Spinning Button On A String

[Turtle]

___Now, a photo of the largest spinning disk on a string ever built!

In the couple of times I've operated it, I have found that most of the frequencies it emmanates are subsonic, ie. below the level of human hearing. It's quite the workout & no small chore finding a second person willing to try such weird stuff. :xx:

[Queso]

you should record it and get a plug-in that monitors and scans the frequencies, just so you can tell what frequencies it generates, you know, for kicks.

 

LETS GET COMPLICATED SHALL WE?:

 

record multiple tracks of it at different speeds, add a lot of panned delay and reverb, and even a slicer or tremelo. different effects on each track. experiment.

Equalize each track differently so that each track has a unique frequency response. and then all of these tracks are going off like mad left and right infront of you and behind you (and of course add insane modulation) and you get lost in noise with no tempo, just organic rhythm.

if you actually experiment with something like this, make sure your microphone picks up subsonic frequencies.

well the question now is would it matter?

it would probably mess with your head, and that's always a good thing.

[Turtle]

___All of that & more! :) The point you make about recording is well taken & the audio file of the small Khua has these frequencies as well, but they aren't picked up. :) I simply don't have the kind of equipment necessary. All the more reason to encourage you all to build your own & experiment! :xx:

___This is a VERY old device & has been used for magic, music, meditation, & play. I never tire of how complex it is given its simplicity. Oh to have an audio lab!!! So many of our topics here tend to the theoretical & this little thing is so hands on!

___Well, ... I run on. Just believe me when I say we haven't even scratched the surface. :)

[Turtle]

___In retrospect, Physics & Math may not be the forum for this as it hasn't prompted much discussion in that vein. Maybe Watercooler? Maybe I'm stroking a deceased equine?

___Orby, if you go to a place that sells buttons & get a large one (better if not round for more sound), then just thread on some string, you can experiment with the equipment you have. Just put your mike into you sound effects box/pedal & dibble away. (When one is spinning a disk on a string, one is "dibbling") :(

[Turtle]

___I found in researching this device references to its relation to the bullroarer, & the bullroarer is quite a dynamic device concerning physics & culture as well. Besides good information on the cultural uses, a lot of bad information on the bullroarers' workings is also extant.

___Now many may know the bullroarer from the Crocadile Dundee 2 movie, but indeed cultures throughout the world know & use it. In addition, the bullroarer is a likely presursor to the boomerang, which is also found wordlwide & not just in Austrailia. Native Americans had all three devices, i.e. Diable/Khua, bullroarer, & the boomerang.

___The uniqueness of shaping the spinning disk as a vesica piscis with an airfoil profile is in that it then produces the bullroarer's sounds. Musical instrument, weapon, spirit magic, toy, & Turtle's own obsession, I can't just yet let it alone. ;)

[Doc Cosmo]

Re: Spinning Button On A String

 

As a child I gained the skill of spinning coins, as an adult I find it is still a fasciation. But I noticed something which I can't explain.

 

I used an old coin with edges worn slighty convex. As the spin slowed the coin leaned still spinning and now also rolling in a path several times larger than the diameter of the coin.

 

Rolling in a spiral on the flat supporting surface, with a decreasing diameter and leaning over more and more, held up I suspect by 'spinning forces' in the coin, untill it laid on one side and 'oscillated' on the flat surface making a tone rising in pitch untill all movement stopped.

Can you explain this for me. Is there something usefull to learn from this? :)

 

Doc Cosmo.

[Turtle]

___Yes Doc Cosmo, I believe I have explanations. Your worn coin is unevenly worn & so wanders off. The higher pitch as the coin lies nearly flat is due to conservation of momentum; similar to a diver pulling in their arms in order to spin faster, the coin is pulling in to the table & spins faster.

___Others here no doubt may provide more detailed replys on the physics. Welcome to Hypography.

[Turtle]

___Orby,(et al) here is the construction instruction for Diables/Khuas - is in post #1:

 

 

 

:hyper:

[Queso]

igracias!

[Turtle]

___De nada. As soon as my buddy Ooda gets over to my bluff house, he's going to help me make a small video of us dibbling the four foot diable.

___The round headed kid recently brought home a little plastic diable that was hollow & pierced with holes so as to whistle loudly when worked. I now have in mind a giant hollow papier mache diable to construct. :cup: No end of experiments here!

[Turtle]

___I Googled "spinning disk on a string" today & found some guy patented it as an exercise device in 2002:

http://www.patentstorm.us/patents/6482137.html

 

___I read the majority of the text (most justifying his new twist on an ancient device :rant: ), but in spite of references to drawings, I found no drawings.

___Nonetheless, I still claim my Giant Spinning Disk is the largest such disk EVER constructed & operated. :rant:

[Turtle]

___I see another thread is discussing perpetual motion & it is strange but that is often the first suggestion people have made when I show them a large disk spinning. The way to make them abandom this mistaken view is to make them operate the disk.

___I still like the idea of building a machine that operates a spinning disk on a string. :)

 

PS The sound of the Khua link in post#14 is no longer valid :D ; Orby's moving. :) I'll see what I can do to get another up. :D

[alxian]

i think building a desk toy out of highly flexible rubber/polymer would be cool, position it vertically and have a counterbalanced weight on an armature, then have a fast action pistion pull the string when its at its tightest and release it once its at its loosest.

 

 

the string whether rubber/polymer/alloy would have to be replaceable like a bow string.. but having somthing dynamic like that on your desk would make it quite the enviable paperweight.

[Turtle]

i think building a desk toy out of highly flexible rubber/polymer would be cool, position it vertically and have a counterbalanced weight on an armature, then have a fast action pistion pull the string when its at its tightest and release it once its at its loosest.

 

 

the string whether rubber/polymer/alloy would have to be replaceable like a bow string.. but having somthing dynamic like that on your desk would make it quite the enviable paperweight.

 

___Vertically is a cool idea; I didn't consider that. :eek: The weight too! Good thinkin' Lincoln. :lol:

[CraigD]

When I was a kid, I had a 2-person beach toy consisting of a plate-sized disk with a couple of holes near its center, threaded with couple of about 20’ lengths of 1/8” nylon string, ending in sturdy plastic handles. Spreading the handles made the disk travel up and down the strings as it spun. It could kick up some sand, too!

 

Alxian’s vertical-with-a-weight worked pretty well for me just now using my curtain rod, some thread,the biggest button I could find in my sewing box, and an (empty) beer mug – it went for about 10 seconds, 6 or seven cycles. The mug rises and falls a good distance, so hopefully some sort of switch could be rigged to trigger a motor to keep the thing going indefinitely.

 

Feedback systems seem a bit daunting, though – I’ve a Leggo Mindstorm kit, but my experience with rigging such systems has not been encouraging.

 

I wonder if something involving a couple of arms, a pivot, and a motor driven cam, without any kind of feedback, would work?

[Turtle]

I wonder if something involving a couple of arms, a pivot, and a motor driven cam, without any kind of feedback, would work?

 

___Yes! Exactly the layout I had in mind for a horizontal (string) machine! The key to this I think is the shape of the cam; in my mind's eye I see the vesica piscis as the cam.

___Nice story, by the by, of the beach toy. I usually work my plate size disks with one end tied to a wall; it's hard to find awilling partner. The few times I worked them in tandem, we never tried the sliding action; great idea. :lol:

[Turtle]

___As I think of it more, the cam must have bilateral symmetry both X & Y. The ratio of the short diameter is bearing on the arm when the string is at it's most twisted, the long diameter when the string is completely untwisted. This ratio is easily taken from the actual string; measure the intended length untwisted, twist it up & measure again. The shape of the curve of each quadrant is now the question.

___Actually , I may have the bearing part backwards in regard to a pivoted (lever) arm. Maybe springs in there too? :lol: Maybe just the string will self correct wild oscillations once the machine is working? :ud:

___I have a drawing of a human-powered fancifull vertical machine; back in a while with it. :eek: