Magnet Butterfly

We call it the Magnet Butterfly! Or maybe it should be called the Magnet Humming bird since we needed to film it at 1/8 speed to get a good look at it in motion!

It is a little contraption that uses diametrically magnetized (magnetic poles in line with diameter rather than length) magnets to constrain a rolling-contact joint.

This type of joint allows for low friction even under high loads, and inherently compensates for the thickness of the panels for folding. The math defining the folding motion of the two panels, however, is much more complex than a standard pin/hinge joint, meaning that applying this type of joint to thick origami adds an extra challenge.

The rolling-contact joint has also been researched for lumbar disk replacements, joint replacements, and compliant bearings such as the CORE joint.

We hope you enjoy this fun demonstration of a rolling contact joint!

3D Printer and any filament

3D model

https://www.printables.com/model/1594546-magnet-butterfly

Cylindrical Magnet Specs:

- Diametrically Magnetized

- 1/2in long

- 1/4in diameter

- QTY 4 needed

Rectangular Magnet Specs:

- 1/8in thick

- 1/4in wide

-1/2in long

- QTY 8 needed

Order Magnets from desired supplier

Here are some options

A link to compatible Diametrically Magnetized Magnets:

https://totalelement.com/collections/disc-magnets/products/1-4-x-1-2-inch-diametrically-magnetized-neodymium-rare-earth-cylinder-magnets-with-black-nickel-coating-n42-20-pack

CAUTION:

make sure the cylinder magnets are Diametrically magnetized. Poles through the diameter, not the height.

A link to compatible Rectangular Magnets:

https://totalelement.com/collections/block-magnets/products/1-2-x-1-4-x-1-8-inch-neodymium-rare-earth-bar-magnets-n42

Print in an upright orientation as pictured.

Push magnets into the 3D printed housing.

TIP:

If the magnets get loose, wrap some thin tape to the magnets to make them fit snug.