Hyperboloid Made of Coaster and Elastic Cord

by HandicraftRecordBook

7.9K13011

Intro: Hyperboloid Made of Coaster and Elastic Cord

Hyperboloids are beautiful curved surfaces. It is a curved surface, but it consists only of straight lines. This instruction uses a coaster and a rubber cord to make this hyperboloid.

STEP 1: Draw the Position to Make a Hole


Draw a circle on the paper that is the same size as the coaster.

Divide the circumference into 24 parts and draw a point at the position to make a hole.

STEP 2: Make a Hole on the Circumference

Drill a hole at the drawn point. (same diameter with elastic cord)

Stack two coasters and make holes at once.

STEP 3: Make Center Hole

Make a hole in the center.

Hole size is little bigger of the wood screw for free rotation.

STEP 4: Make a Hole in the Center of the Stick

Make a hole in the center of the stick both side.

Hole size is according to wood screw.

STEP 5: Assembly Coasters and Stick

Assembly the coaster and stick with screw.

One side should be tight.

Leave a space on the other side for free rotation.

STEP 6: Pass the String Into the Hole

Thread the string between the two coasters in order.

STEP 7: Complete!

Let's twist!

The shape you find is hyperboloid of revolution.

9 Comments

ggallant571 2 years ago

I made one using 3D printing. Wondering if there is a magic ratio between the diameter of the end plates and the space between. First attempt was about 1 to 1 while the second almost doubled the span. Liked the shorter span better but looks like it could be improved.

HandicraftRecordBook 2 years ago

Thank you for the comment!
May be it is depends on the view point from Mathematic or Engineering.
I'm not a mathematician so I'll give my view as an engineer.

Attached photo is chair in my grandmother's house. I feel it is beautiful because the area and height of the seating surface are suitable for sitting.
If this were more constricted, it would be more anxious than beauty. If the seat was smaller, it wouldn't function as a chair.

On the other hand, this link is Kobe-Port-Tower in japan. if the ratio is same as that chair, it is not beautiful as "tower".
https://www.google.com/search?tbm=isch&q=%E3%83%9D...

I think best ratio is depends on the product and the function :)
(as engineering)

ggallant571 2 years ago

Thanks for the reply. Building one with a ratio of 1.000 and another with 1.618 just to see if there is a difference. Guess I get stuck on things.

wolfCatWorkshop 2 years ago

Very nice! I like when relatively simple projects have such a rewarding result.

jessyratfink 2 years ago

I love this! It's so mezmerizing to watch :D