The assignment

The assignment for this week was to build a 3D model composed of parts that could be cut in a laser-cut machine. One of the requierements was to document all the process of the design, preparation and cutting of the whole model.

For the past years, during my career of architecture, I have developed several models with computer-controlled cutting, specially with the laser cut machine. You can check some of my models in my portfolio.

As I did for the last week a 3D model of a bust of a monster with and advanced modelling plugin for Rhino, I decided that it was a good idea to represent this figure as a reak representation through a physical model. I have seen models like this made out of unfolded paper like origami, and other representation made of sections in several directions of the whole model. I decided that the best way to represent such a complex 3D model, was actually to build a model made of sections, some done horizontally and some others done vertically in both directions of the figure.

I knew that the best way to do this, was using some parametric software. As I was using Rhinoceros for my 3D design, the most practical way was to use Grasshopper plugin for Rhino. I have used this software for several years, as it has become very popular in architecture. I mainly have used it for solar optimization of a building and for advanced modelling of shapes and roofs.

I had some issues trying to install it, as I did not have the latest Rhino update, and as I was on a hurry for the delivery of the assignment, I decided that I could do it in the common way: creating 2D sections and think about the assembling between them. I drew some skecthes of which sections would be necessary for the whole model comprehension.

The laser cutting

The machine that we have in our FabLab in Madrid is a GS Goldensign, imported from China. As it is located in a public space of the university, where all the students have access to it, there is a computer with the suitable software recommended by the manufacturer, and I was not allowed to install the software recommended by the course: Fab Modules.

I used this machine many times, so the work ahead was very easy.

1. I fitted my sections in a single 100x70 cm cardboard panel, the largest format that allowed my machine, and saved the DXF archive into a pendrive. It is important that the measurements are in milimieteres, so the machine recognize them in the same scale.
2. There was not an exact scale ofthe model, as I just invented it through the modelling, and it is not a "real thing" representation, so I just fitted the whole sections in the cardboard so the scale was big enough to understand the model and to fit all the sections in just one piece of cardboard (it was cheap, it cost me 1.20€)
3. I assigned a cutting pattern to each of the layers in the drawing. I had 2 cutting layers (55/65/50) and a single marking layer (85/15/10), where I numbered the sections of the model so the assembling was easier.
4. An important thing to ensure a nice cutting, is to measure the distance from the caredboard to the laser head. It is very important as if the distance is too big, it won't cut properly.
5. Done that, we can proceed to send the file into the machine and start cutting. One last thing before the final cut, is to test the cutting: it will make a previsualization of the border of the cut to make sure that all the cutting is being done inside of the cardboard.
6. After the cutting, the funny part starts: the assembling.

The assembling

The assembly of a model like this is very easy. It is important to do some previous sketches and demos of what is going to bring out the laser-cut machine for us. If we do some previous tests of what is going to happen, we can succeed every time we do a model like this.

1. If we have a large model, where there are going to be lots of sections, it will be very helpful to mark our sections with a numeration, in order to assembly them easier.
2. It is important to choose a proper material. If our model is going to be a final model for an presentation, the cut is as important as the chosen material. Not all the materials are appropiate for the laser-cut machine, some of them are even forbidden, but the best way to find out this is to try different materials and discover which one is the best for our assignment.
3. Finally the assembling has to be done very carefully. The pieces may be very delicate, and may break as we do the assembling.

The mistakes

The best thing to learn in this type of models, is to try to find out what mistakes could be undone with a previous organization:

1. The material should have been thiner, so there would be the possibility to do more horizontal sections and the definition of the model would be much better.
2. The material should be cleaner, a white material would have been perfect, so the burnt border would stand out of the rest of the material.
3. A parametric sectioning would have been perfect, so all the flanges would adapt perfectly to the shape of the model.

Other laser cut models

Along my career I have done many models with this machine, so I feel kind of expert in this hardware.

I graduated recently and I had some free time for doing other stuff that i was interested, here is ana example:

- Beer 4 pack.- I am starting to brew beer in my house, and I designed and fabricated a box to bring 4 bottles at a time. After some designs and proofs done at home, I finally got into the final design and made the real model in the laser cut machine.

Wooden glases prototype (7/04/2014)

This past weeks I wanted to do something for my own and for some gifts for my friends. Here ar two prototypes that I have done.