Yoshimoto Boxes

The Yoshi Box is a hinged toy reminiscent of the folding patterns of a Yoshimoto Cube, but it employs mechanical hinges to allow the pieces to be folded into a endless cycle of shapes.  The pictured model is available for purchase from Shapeways or Sculpteo.

This toy is made up of eight bisected boxes, each attached to two of its neighbors with mechanical hinges.  This sample was built in nylon SLS with the hinges already fused together.

The small tabs enable two models to be snapped together so they'll move in harmony with each other.  I suppose you could hide small treasures inside the boxes, too.

The inspiration for the Yoshi Box came from Yoshi Prime, a previous Yoshimoto-like toy I built on my SD300 using living hinges.  It's built in one piece with thin, flexible plastic connections that permit it to be folded in each axis.

Here's a closer view of a living hinge.  To build a vertically-oriented living hinge on the SD300 I bridged the connection between adjacent cubes with a wall 0.3mm thick, with a graceful curve to spread the stresses as much as possible.  I suspect it would have a limited life because of the amount of bending required, although it hasn't broken.  (Yet.)

This model combines the box-like style of the Yoshi Box with the living hinges of Yoshi Prime, forming a group of 8 small treasure-boxes connected by living hinges.

My first functional Yoshimoto Cube

Ultimately I would like to 3D print a fully-functional Yoshimoto Cube in one piece, but I really need a solid reference model to help me visualize the design. So I used the SD300 to build the individual hinged panels and glued them together one-by-one.

This black one is almost assembled; the hinged panels at right will be joined with the already-assembled group at left.

I built and assembled a pair of Yoshimoto cubes, one in black and the other using transparent amber.

The geometry of a Yoshimoto Cube is peculiar and confusing, so it'll sure help to have a physical model for reference! So far I've observed a few details that could enable me to build the model in one piece.

Yoshimoto experimentation

In July 2010 I saw plans on Thingiverse for building a kit that could be assembled into a Yoshomoto Cube, which is a type of folding puzzle. At that time I didn't have much experience with hinged models, so tried to adapt the concept.

I built a pair of experimental models that had hinges in each axis, some horizontal some vertical. This picture shows the two models before I'd finished removing all the support matieral; they look like they're attached, but I subsequently separated them.


One separated, the models could fold along the hinged connections. They were somewhat delicate (and tiny!) but each could be folded into many shapes just like a Yoshimoto cube.


Careful folding and unfolding would permit the model to change shape until it was inside-out from its starting position. The model on the left has been inverted, while the one on the right has been returned to its starting position.


Also like a Yoshimoto cube, the inverted and non-inverted models could be nested together in such a way that the combined pair could still be folded in all the same ways as before.


After a few hours' of use both models broke along one of their vertically-oriented hinges. I didn't continue with the project at that time...and now a year has passed by.

Recently I've gained a lot of experience building models with built-in living hinges, so I want to try experimenting with the Yoshimoto cube again soon.