Here are some interesting examples of laser cutting where software techniques are used to slice a 3d computer file into 2d shapes to be cut for re-assembly as a physical model.
The free Autodesk software 123DMake will import a 3d file (.STL) and then generate 2d cut-able parts that are used to construct the model. It can do this in a variety of styles:
The model is simply divided into slices that are assembled on top of each other to form the shape. Typically the model is sliced horizontally but the software does give the option to change the slice angle so the shapes run front to back for example. This is the easiest type of model to assemble and gives the most accurate form, it’s likely to create the most amount of cutting though
This was a quick 3d studio model (render on right) – a lofted circle shelled with much twist / bend / taper modifiers applied to it. The laser cut model looks (and feels) a lot better than the stark flat computer render.
A version of Zaha Hadid’s Heydar Aliyev Centre in Azerbaijan. The 3d model was downloaded from 3D Warehouse and fixed in 3D Studio (3d Warehouse models often need repairing before they are ready for cutting).
A skull model that was actually captured using iPad 3d scanner software (another free piece of Autodesk software called 123Capture). This takes many photos of the shape and creates a 3d file from that information. The file can then be brought into 123DMake and made into cut layers.
In this model each layer has been padded with a piece of card – that card should actually have been thicker as the skull still looks a little squashed. On the right is a photo of the same model (proper dimensions) printed on the z450 3D printer.
This model was printed on 1.5mm grey card and gives a quite smooth version of a head. The model has been smoothed on the right hand side by sanding and Dremeling it down – however the dirty, rough non sanded version is has a nice textured quality that is lost on the clean and smooth version.
In addition to the relatively straightforward stacked slices the 123DMake software can also generate model cuts in a more figurative way:
In this image the model on the left is the original followed by three possible variations of “interlocked slices”, “curve” and “radial slices”. The parameters for each can be tweaked to alter the number of slices and spacing – this could be useful for mimicking floors / storeys in a building model.
Here is a real version of a radial sliced model, using 1mm grey card.
This radial slice version of the “Walkie Talkie” building in Fenchurch Street London had a shell modifier in 3D Studio applied to so it is just a thin hollow shell. The slice operation then creates a skeletal form rather than solid planes. The result is quite striking and only uses a small amount of material.
These types of models do use less material but they are more difficult to assemble – like a 3d jigsaw. With complex shapes with gaps in the middle slices have to be put together in a particular order – the software in fact has a feature where it will show the order to put them in.
The slot models are less detailed than the stacks and are not suitable for all situations for example if more detail is needed. They can make for very interesting conceptual models though.
The software also has the option to create a paper model version that can be folded and glued together. It is an appealing idea for quick, cheap paper models but the reality is that it’s only the simplest of shapes that produce a usable result. Here is what the software makes of head shape and simple house shape
The head would be quite difficult to fold together correctly and probably would not give a great result.
These models could conceivably be cut on any laser-cut material, e.g plywood, acrylic, cardboard, etc. – the software does allow for the required layer thickness to be altered to match. For the slot models it is a lot easier to work with a material with some flexibility like card rather than a rigid material as the parts do need to slide together and interlock. For a more advanced project a mixture of materials could be used, for example wood for the horizontal slabs and clear acrylic for the uprights.
The interlocking models ought to fit together with no glue needed whereas the stacked models do need to be glued – this can take some time and patience. Complex multi layered models would also mean a lot of cutting so although a cost saving could be made on using cheap materials like cardboard, the actual cutting time can be long, especially when multiple sheets area required to be cut.