Almost any 3D shape can by constructed by stacking a large number of carefully cutout layers. This method of construction is popular with architects when creating models of terrain and artists creating sculptures with an edgy effect. Layering can also be used as a rapid prototyping method (known as
Laminated Object Manufacturing).
The problem with making 3D shapes with layers is the number of layers necessary to form a smooth finish. Using thicker layers is quick and easy, but at the cost of a stepping effect (resembling rice terraces). Using thin layers overcomes the terraced look, but requires a large number of layers which is time consuming and restricts the type of materials that can be used.
If the angle of the edges could be varied when cutting out each layer, a much smoother 3D shape could be constructed with relatively thick layers.
This would be achieved with a computer controlled scroll saw (a scroll saw is a hybrid of a bandsaw and jigsaw). The sheet would be pushed into the blade by three actuators (one for movement in the x-axis of the plane, one for the y-axis of the plane and one for rotating the sheets in the plane (i.e. the yaw)).
The surface on which the sheet lies when being cut would be moved in the roll direction. Thus the angle of the edge could be varied.
The layers could be made of any material and adhesive applied between sheets when stacking. Two or more alignment holes could be cut into each layer (with alignment rods threaded through holes when stacking the layers).
For a robust object, metal sheets could be used and adhered with thermite welding.-- xaviergisz,
Apr 15 2008
Model for Sunken Monument
http://www.arts.aus...401/livingtogether/example of an artist using layers for a sculture - looks like a Darth Vader mask melting into a puddle (scroll halfway down the page) [xaviergisz, Apr 15 2008]
Laminated object manufacturing
http://en.wikipedia...bject_Manufacturing [xaviergisz, Apr 15 2008]
spatial sampling theory
http://www.google.c...+sampling+theory%22Possibly relevant Google search [csea, Apr 16 2008]
Couldn't you have a composite process - thick layer for the inside bulk, with thin layers at the edges to give the surface detail/curvature?-- DrCurry,
Apr 15 2008
I guess you could use a composite process DrCurry, but I can't see much point. If you're going to the effort of cutting hundreds of thin layers to form the surface, you may as well use the same layers to form the interior of the shape as well.-- xaviergisz,
Apr 16 2008
I like this, + and have spent some time thinking about the ramifications. The illustration is a fairly simple radially symmetric object, and works nicely (depending on the scale.)
More complex shapes would take considerable detail to shift the angle as the radius completes the circle.
What's the tradeoff between more layers versus more complicated yaw information?
Seems that the Nyquist sampling criterion is relevant [link].-- csea,
Apr 16 2008