Hyperball

[rolly_wood]

Waiting for the instructions for doing Hyperball, (I will post them soon), here is a 3d photo.
Invisible ink: THis is just a copy of a post of the "other forum", for those who do not log there.

It is an only cord, 24 meters long which traces 24 portions of hyperbolic paraboloids which surround and support a wooden ball
It was realized by me but thought by several users of the italian forum il-legno. The idea of hyperbolic paraboloid took origin by seeing a garden framework structure
The real puzzle is to weave the net with an only wire starting and ending in the same point.

If you want to view Hyperball structure in 3d you may find funny to look at

full screen, place a mirror orthogonally between the two images with the mirror surface leftward. Then look right with both the eyes, the right one will look at the right image directly, the left one will see that one reflected by the mirror like shown below.
It is useful to try to close one eye at a time to verify that the field of view covered the area of interest. The best results are obtained in the darkness (but the screen  )


ciao

[Canuck]

Very cool....Chinny must be 'chompin at the bit' to make one

[Chinnomotto]

Psssst,The Chinny is waiting for the Instructions

[rolly_wood]

Hey I must confess: Rolly Poly is unable to find the sequence file. just a photo:

http://img83.imageshack.us/img83/7/dscf4160lc9.jpg

but all the numbers are not readable! Stiill searching.............

EDIT : another photo
http://img140.imageshack.us/img140/8093/dscf4159im6.jpg

now read all the figures. Good - 

[Chinnomotto]

O my God!
I'm in Heaven
I'll have to try it with fishing lines, 24 m eh?
Don't worry, I'll be emailing you  with Step 1
You are 1 of a kind. Thanks

[rolly_wood]

the weaving of hyperbolic paraboloid (HP) "sails" must be done between neither adjacent nor parallel cube sides. It means that each cube side will see 4 other sides with which be connected for doing HP sails. Edges are 12, divided by 2 times 4 =24 HPs.
The weaving of each of them is sketched in figure. Following this scheme and the previous one visible on the photos of the above post, is it possible to weave 24 HP sails with the same wire coming back to the starting side. I used nylon cord 0.5 mm diameter. In the next post if someone is interested I will give diameter of the sphere and side of the cube. Actually I need to slightly rescale them because I trusted in the computer  but the wires get loose and now the sphere does not fit exactly the wire cage, it is slightly smaller than that.
Chinny are you still in the pool? 

ciao

[Chinnomotto]

Yeap to the poool
Yeap to the size ball vs size cube
Must be a way of re tensioning it
What a cool puzzle to make. Amazing

1 more egg to go
And 3 variations
Then I am ready

[rolly_wood]

Yeap to the size ball vs size cube
Must be a way of re tensioning it

if you are patient, the original intention was to use 40 m of cord like this
The theoretical diameter of the ball is 1/sqr(2) = 0.707 the internal net side of the cube. I would suggest to shorten the side of the cube at least 5 mm (respect to about 12 cm). However since you have the lathe (I had to buy a wooden sphere and scale the cube on that value) it is better you do first the cube, weave about half the net and then turn the sphere according to.
tensioning the cord is hard! The only thing I imagine is a cube with "variabile geometry"... with springs?....but how? better use an stretchable cord
ciao

[Chinnomotto]

OhhhO I like this one better

So No1 goes with No2 ,,,,,,,,I give up

Have you made one of these?

Maybe tensioning the strings, get a bigger ball??

I have a ball cutter, to size 100 mm diameter,

if you need any size smaller,i can make and send, any woods

[rolly_wood]

OhhhO I Have you made one of these?

No, I have not.

Maybe tensioning the strings, get a bigger ball??
I have a ball cutter, to size 100 mm diameter,

Yes putting a ball bigger than theory should be the easiest soln.
10 cm is perfect, the mine one is 92mm but is at least 3 mm smaller than it should be
100 mm should be ok to tension the string. When I get home I will post the side of the cube.

if you need any size smaller,i can make and send, any woods

thanks you're very kind... but I will not open it anymore because once the ball is "in the cage" it is needed to weave string around and you can no longer extract it.

[rolly_wood]

the internal side of the cube is 122 for a l"loose " sphere of 92mm diam.. it should be 95mm.
For a sphere of 100mm diam I would use no more than 130mm vs a "theoretical" guess of 141mm.
Theory is a good point ma does not take into account stretching of string!

[rolly_wood]

You know, when you do not search anymore one thing and you think it is definitely lost, it is the time you will find it.
This is the sequence of the connections

[attachment deleted by admin]

[Chinnomotto]

Dear Mr P, or Mr R....

Interesting,,,,dumbass question,,,,,you have 2 numbers on each edge, does that mean 2 strings, then repeat for each 2 strings?

I counted 9 strings per edge on the upper pic ,so it means you run out of holes , so you place 1 string

I guess the only way to learn is t make 1

Thanks mate,,,,SC

[rolly_wood]

Dear Mr P, or Mr R....
you have 2 numbers on each edge, does that mean 2 strings, then repeat for each 2 strings?

I counted 9 strings per edge on the upper pic ,so it means you run out of holes , so you place 1 string

No, please do not mention that English Sir, continue to all combination of rolly roly poly and so on 
2 on each edge just because "sails" are 24 and cube sides 12. You need to start from 1 to 2 as shown in the pic above, next 2 to 3, .... , 23 to 24, and last 24 back to 1.
You are right that I omit an instruction: since the holes are an odd number, you change side every sail, that is the key... HOWEVER you end one sail with the cord pointing outward the cage, you need to return back in the first hole of that side, cross it, and point inward to begin a new sail.
This woudl be difficult for me even to explain in my language... I do not expect to have made things clearer... it is simpler to try making one, of course.
I will be happy if you will so