Spinning Button On A String

[Turtle]

___Here we go then:

___You might have to push down on the sticks as well as jump; you need the sticks anyway so you don't twist right round too. Note I have one side fixed on a bearing & string twisting on the other side of the disk only.

___ I hear the saw already. :lol:

[Turtle]

___As I think of it more, the cam must have bilateral symmetry both X & Y.

___On reflection the above is wrong. The cam may have bilateral mirror symmetry on 1 axis, likely the longest. I have to make some little drawings eh? :) I love the beer bottle-curtain-rod-button-thread setup; fabulously scientific experiment.

___Race to a working model anyone? :lol:

[Turtle]

___From the drawing above, many variations now have an easier visualization. From a -

double-arm-twin-double-action-cam-machine, try:

double-arm-twin-single-action-cam-machine, or

single-arm-single-double-action-cam-machine, or

single-arm-single-single-action-cam-machine.

___I haven't made an effort to build such a machine yet; maybe. :eek_big: :eek:

[Turtle]

___Ok, I admit to haveing a 2x6 board selected as a platform, but I whole-heartedly deny having measured it, bored holes in it, or in any way yet physically beginning to build my machine yet. ;)

___One note on Craig's vertical machine is that in practice the disk always slips downward in increments on any string orientation other than near horizontal. The slip is phased with the complete unwind state in the cycle of wind-right-stop-wind-left-stop...etc. I note this is also the point of the disks maximum rotational velocity, which also means its maximum gyroscopic action. The string is the axis of rotation however & so movement up or down it is unnaffected by the gyroscopic force & the mass/frictional-coefficient/gravity forces determine how far/how fast the disk slides down the string in a vertical machine.

___I now have in mind to make a little drawing of using 2 disks to affect a unique aural effect. ;) Off I go then; I trust my vicissitudinous manner is not overly disconcerting to antidisestablishmentarians or their opposites. :(

[Turtle]

___I have made a short recording of a single disk as well. Enjoy.

 

PS Multiple machines might expedite the exploration of these sounds; I haven't figured out how to put my head at that intersection & operate the disks at the same time. :hihi:

[Turtle]

___In thinking over my machine design I decided to gather some measurements from the disk I use pictured in post #10 & recorded in the previous post. Measurements approximate.

 

Disk:

Long Axis 3 5/8"_______92mm

Short Axis 2 5/8"_______54mm

max thickness 1/4"_____7mm

 

String: 1mm braided satin cord (nylon)

Length unwound 33"___850mm

Length lightly twisted 30"

Length tightly twisted 28"

 

The 8 step cycle:

power unwind left

unwound thump

momentum wind left

stop

power unwind right

unwound thump

momentum wind right

stop

 

Operating the disk by hand, a slow rate is about 30 cycles per minute where a cycle is from stop to stop. A fast rate of operation is 60 cycles per minute. Maybe that's enough to calculate the speed of a disk? :) Off to experiment. :doh:

[johnkwhite]

Turtle

ya all done good

jkw

[Turtle]

Turtle

ya all done good

jkw

Thanks John; ya'll are too kind. ;)

 

___A couple posts back I proposed calculating the speed range of my little disk, suggesting I gave enough data. Obviously I did not, & here is the bit you need to make the calculation. The fastest speed results in the tightest twist, & for 60 cycles per minute the maximum twist count is approximately 45. I found about 30 twists for the slower range.

___Review of my machine drawing earlier has me thinking that if I want to use the vesica piscis as a cam, I have to adjust the fulcrum of the lever arm so that the ratio of long/short axis of the cam is in register with the ratio of long/short (untwisted/twisted) length of the string.

___That's enough for an afternoon's experiment. :Waldo:

___Afterthought: Uncle Al mentioned Peaucellier's linkage somewhere as a project & it occurs to me that the diable (spinning disk) is something of an inverse of that linkage. Whereas Peaucellier's linkage converts rotary motion to straight in-line motion, the diable converts straight in-line motion to rotary motion. While the diable doesn't have much capacity to do any work, the transfer principle is manifest. Here's a Wicky on Peaucellier's sticky: ;)

http://en.wikipedia.org/wiki/Peaucellier-Lipkin_linkage

:hyper:

[Turtle]

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?

___In mulling this machine as I have proposed it, it now seems apparent it may work if the speed is not varied. Because the string twists tighter & therefore shorter with an increase in speed, a fixed cam won't accomadate the changing string length. More simply, you can't just speed up the drive motor to speed up the disk.

___Is this really a hard machine to build? Simple enough for grade school? High school? College?

Question: When is a toy not a toy?

Answer: When it's a physics experiment. :)

[Turtle]

___Not much progress...Ok no progress, on building my machine. No material progress at any rate. I have put a little thought into whether or not the addition of a spring between one end of the string & its drive arm might ameleorate the shortened string at higher speeds. Is a spring in this sense a feedback device?

___Any of you eager beavers working on your own prototypes? :evil:

[Turtle]

:naughty:

___Afterthought: Uncle Al mentioned Peaucellier's linkage somewhere as a project & it occurs to me that the diable (spinning disk) is something of an inverse of that linkage. Whereas Peaucellier's linkage converts rotary motion to straight in-line motion, the diable converts straight in-line motion to rotary motion. While the diable doesn't have much capacity to do any work, the transfer principle is manifest. Here's a Wicky on Peaucellier's sticky: :D

http://en.wikipedia.org/wiki/Peaucellier-Lipkin_linkage

:xx:

 

___To clarify, Peaucellier's linkage not only converts (transforms) rotary motion to straight line motion, it works the other way as well, i.e. it transforms straight line motion to rotary -circular - motion. The linkage is nothing more or less than sticks & hinges, & yet until Peaucellier 'just made it' it was not known to exist. Curiouse & curiouser.:xx:

[arkain101]

Interesting topic.

This is the first time I have ever came across it and coincidentaly I was pondering this exact mystery a few months ago.

 

I found myself waisting time in front of the television and fiddling with a wire for an electric charger of some kind. I began spinning it and pulling and losening it. Then my attention was turned fully to what my hands were busy fiddling with. I began pondering how this effect could have importance, where it could be applied, also wondering how you could create a mathamatical understanding of this. Then after considering it in the atomic world or the invisible atomic world, I let it go. It wasnt long after that I came across the "String Theory" for the first time aswell and found it interesting my thoughts were strikingly similar to existing theoretical ideas.

Anyway, I also have/had a strange wondering about this effect.

[Turtle]

Interesting topic.

This is the first time I have ever came across it and coincidentaly I was pondering this exact mystery a few months ago.

 

I found myself waisting time in front of the television and fiddling with a wire for an electric charger of some kind. I began spinning it and pulling and losening it. Then my attention was turned fully to what my hands were busy fiddling with. I began pondering how this effect could have importance, where it could be applied, also wondering how you could create a mathamatical understanding of this. Then after considering it in the atomic world or the invisible atomic world, I let it go. It wasnt long after that I came across the "String Theory" for the first time aswell and found it interesting my thoughts were strikingly similar to existing theoretical ideas.

Anyway, I also have/had a strange wondering about this effect.

 

Arkain, I like your hands-on approach. Find instructions for making a spinning disk in the Science Gallery.

The device I rementioned, that is Peaucellier's linkage, is constructable by anyone who can measure, use a saw & drill, & screw a bolt. This device, this Peaucellier's linkage, inverts a curve. Google Peaucellier's linkage for instructions on its construction. To make it perfectly clear:Peaucellier's linkage squares the circle. It IS the square peg in a round hole. Literally, not figuratively. Again, Peaucellier's linkage squares the circle. Thanks for your interest Arkain.:naughty:

Instructions to Build Spinning Disk attached in post #1

[Turtle]

___What goes around comes around; wax on, wax off; inhale, exhale;clockwise, counterclockwise; twist, untwist.

___Tomorrow's forecast is clear, dry, & very cold. Tomorrow Racoon & Turtle plan to team up & spin the giant vesica piscis discis out in the open air under the oak trees. Tomorrow we make a movie of it. Tomorrow you get to see it. Tomorrow if it comes is gonna make one heck of a day.

___I bet I hardly sleep.:cup:

[Racoon]

Would the fresh paint job on the Diable happen to be of the Cadmium based kind???:cup:

[Turtle]

Would the fresh paint job on the Diable happen to be of the Cadmium based kind???:cup:

 

___Why yes of course; cadmium red it is! Carbon black as well. At nearly four feet on the long axis of the large khua, this is at minimum a two person job. I love it when a plan comes together. This khua is over a year in the making & now is ready to play.

___We two forest creatures take up positions side-by-side. In our paws, a stout log of one fathom length. At the midpoint of the log, the khua's rope which moves away from us at a right angle from our log, passes through the two holes in the khua, and thence an equal distance to a 500 year old Oak on which the rope is secured by a larks head to a khua bridle.

___The frequency of much of the sound I expect is below the normal threshold of human hearing, but the Whales, & Elephants, & Mother Earth have much wider latitude in this regard.

___Of course, I have yet to receive Racoon's instructions in regard to particulars; everything in good time.:cup:

 

 

PS my gratitude to the old ones who instructed me in zion canyon.

 

 

 

 

 

:confused:

[Turtle]

___Well now! Well done! Well played!

___I have a short mpeg movie of the experiment I described, but for some reason I get error messages when I try to upload it to the Hypography Science Forum Galllery. I shall make every endeavor to correct the problem.

___It is simply unparalleld in my experience with Diables/ slash Khua.

 

 

 

:cup: