Week 9: Composites

I decided to make a container in the shape of Cambridge city for the Composites week. Here's how the story goes.

Process

I decided to use the same 3D model I generated for Cambridge city for the Molding and Casting week.

The desktop shopbot was set up to do a 3D profile cut on foam.

I set up a small cut depth pass, so the process started out quite slow.

And I had to keep cleaning the foam remains using vacuum cleaner.

When the shopbot was done, I had a nice clean cut of a Cambridge map, on which I would do my next set of experiments.

Using CorelDraw, I created a little oversized Cambridge map by following the key points in the boundary map of Cambridge. I cut this out on the laser cutter on burlap material. This will act as the base of my container.

Yes, almost accurate to the size of Cambridge.

I also cut out a few supporting structures to create the sides of the Cambridge container.

Next, I would have to skip some images, as there was no way I could take images while doing this complicated process. I mixed the right proportion of entropy resins and mixed them well on a cup. Then the cut-out burlaps were pasted with this mixture.

Next, I put several layers of processed burlaps on to the Cambridge city models, using the supporting structures on the sides and the cambridge map as the base. The next layer is a perforated polythene material, followed by cotton to let the air pass through when drying. The whole setup process took a little bit of time because of the complicated geometry on the sides.

A closer look at the layer setup.

The whole thing was put inside a vacuum bag, and air was vacuumed out. I left the bag like that for around 20 hours.

When I came back and opened the bag, it was not too bad.

However, there was some cotton that got hardened and stuck to the container.

So I decided to cut out the extra sides of foam using a saw.

The base of the container still had some leftovers, maybe I could use some wax to make them look much nicer?

Here's the end product, doesn't look too bad, retains the shape of Cambridge (mostly).