For this week's assigment we have to test composite materials.

Here in FabLab BCN we will be using some Linen and Raffia for the matrix and Epoxy resin.

I wanted to make something useful, so I was thinking to make like a small table to put something on it.

I made a somehow complex geometry (again).

The first step is to design the mold, then we have to mill it in foam and then apply the cloth layers with the epoxy and finally put it inside a vacuum bag.

I designed the mold in Rhino, and then milled it in the Shopbot with a 12mm bit.

The Shopbot works with its own software. Its called PartWorks, and it is a very straight forward process. I actually began to like a lot the Shopbot.

We have another milling machine, the Precix, with wich I made the mold for Molding and Casting assigment.
It is a very nice machine, but you have to use RhinoCAM to prepare the job.

Here soma images of the 3D model and the  milled mold:

For next step we lasercut the pieces of cloth. In my case it was a little bit difficult since this surface is not developable.
I tried several softwares and I found a solution as to cut the pieces in parts, but when the moment came to do the milling with the Shopbot, the max depth of the bit was 6cm and my model was 8cm deep, so I had to scale the model and all the pieces of cloth changed......

So the next fast solution was to execute a Rhino command called SQUISH. It actually worked pretty well.

This is my layer configuration:

OK, Now prepare the Epoxy resin mix. This product is called Super SAP CLR. You have yo mix 2 parts of Epoxy Resin with 1 part of Hardener.
Always weare gloves!!

At last you have to cover all the layers with plastic film again, and then we added a Felt cloth as to distribute better the air when the vacuum starts sucking the air inside the bag.