Folding is a powerful tool for both aesthetics and engineering. Many forms are possible using folding techniques, but it becomes increasingly difficult to attain these forms as the crease paths develop more and more complexity and density. By laying out all the folds in software and laser etching the two sides of a piece of paper, much more complex forms become possible. Described here is a method for laser etching elephant hide paper on an Epilog Legend EXT 100 Watt laser cutter to facilitate the complex folds that compose a hexagonal hyperboloid.
Step 1: Prepare Your Files
There are a lot of different ways to lay out your fold paths. I used Autodesk Inventor to lay out a very simple set of concentric hexagons to create a hexagonal hyperboloid form. For simple forms, I recommend laying out all fold paths (both mountain and valley) in the same file (using different layers if your software has the capability to), which makes alignment easier later in the process. You can also separate your mountain and valley folds from the beginning if you choose. For this example, I started with all folds in one file.
Step 2: Prepare to Laser Etch
Step 3: Load the Paper
Step 4: Etch
Step 5: Fold
Start by folding along all the crease paths on each side of the piece, taking care not to "follow-through" across the entire piece: stop folding where the etched line stops. Once you have folded all the laser-etched creases, fold the piece in half three times to connect each vertex in the hexagon (in this case) with a manually-formed fold. Fold each one of these three folds back on itself to make it bi-directional. These folds are best not etched because they see a lot more tension than the rest of the folds in the form.
After pre-folding all the etched creases and applying the radial folds, work you way from the outside in, bunching the folds together and taking care to properly form the intersections of the manual radial folds and etched folds. Because the laser is operating at it's lowest emitting power setting to create the etches, the laser stops emitting as the gantry decelerates when it leads into and out of corners, which means that the etch paths stop "early". The center-most folds may require the tip of a knife or a skewer to enforce the proper topology.
Step 6: Experiment
This is a very general strategy for encoding 3D form information into a 2D stock material. Please experiment with different geometries and materials!