Week 7: Textile as scaffold

This week, I produced a composite using layers of material with epoxy and catalysing solution, layered over a foam mould that I designed in Fusion 360 and milled it with the CNC milling machine, and then vacuumed it.

First of all, I created a shape in Fusion containing curves because I was interested in how the material would respond to the curves. I created a sketch, extruded it and rounded off the edges with the fillet tool.

In order to avoid any collisions with the drill tool, I had to ensure that the height of my model was less than 25mm, therefore I had to amend my design in Fusion and decrease its height.

Once the design was final, I set up the model for CNC milling using the CAM workspace in Fusion:

• Unordered List Item I selected a drill bit and entered its dimensions into the software
• I specified a 'fine stepdown' of 0.5mm for a detailed finish
• I created a 'stock' (block of material) using the dimensions of my model, but adding 10mm to the width (x) and depth (y) to ensure the model would be contained inside
• I selected my 'zero point' - because my model was at a peculiar angle, I had to select the x and y axis orientation, and also flip the x axis

Once the mould was milled, I began the process of layering the materials with the epoxy mixture:

• I mixed a solution which contained 100g of catalyser and 30g of epoxy
• I put a thin layer of this mixture over the mould in order to protect the mould - this took a couple of hours to dry
• Once dry, I put a layer of foil over the mould and then sprayed some silicon to make sure the fabric wouldn't stick to the mould
• I then proceeded to fix 4 layers of fabric with the epoxy solution. The final layer of material also needed a layer of epoxy
• I placed a layer of plastic wrap over the model and then put it in the vacuuming machine for 30 minutes

After the model was vacuumed, I removed the composite from the mould and tidied up the edges using the sawing machine. Here is the final product:

Problems

The composite was a little difficult to remove from the mould - perhaps I didn't use enough silicon spray to separate the fabric from the mould. Also, the shine didn't work over the whole top of the composite - particularly in the parts that were depressed. Perhaps making a negative mould to press all the parts evenly would have fixed this problem.