Fab Academy 2017
Learn how to make ALMOST anything!

Composites


This week's task was to design and fabricate a 3D mold (~ft2) and produce a fiber composite part in it

To be honest, this is my first time ever to work with composites, I had a lot to learn about it. To start with that, I read more about What a composite is, then how their fabricated and the ususally used manufacturing processes.

A Composite is a material made from two or more different materials with different physical or chemical properties that, when combined, are stronger than those individual materials by themselves.

 

One of the very good Channels I found on youtube explaining more about the composites and showing manufacturing process tutorials is "Easy Composites Ltd"; especially this particular video: "How To Do Perfect Vacuum Resin Infusion of a Carbon Fibre (Fiber)".

 
 

As it was a first time, I started with a very simple design, "A small table plate".

Using Fusion 360, I developed the design. The dinmensions are:

  • Base diameter: 20cm
  • Height: 2.5 cm
  • Small base diameter: 6cm

Scetch

3D Model

 

Using SRP Player for Roland MDX-40A machine, I developed the toolpath for the plate. I used for this task a 6 mm Ball Nose end mill.

The total estimated time for "Roughing" and "Finishing" is 4 hours.

3D Model

And the machine tured Blue because of the foam! :D

Roughing Final Mold

Prepraring the material for casting:

The Material I used are:

  • The Mold made out of foam.
  • Epoxy + Hardener, with ration of 2:1.
  • gauze, served as the main fiber.
  • Light plastic sheets (used with food).
  • Vaccum Bag.

To start, we tested the vacuum bag and its sealing to make sure it was fine to use and there is no air leakage. It worked perfectly fine.

testing the vaccum bag

Next step was to mix the epoxy with the hardener. The ratio that gave good results after trying was 2 (Epoxy): 1 (Harderener).

Getting to Work:

1. Cut Gauze to small piece that will later form the layers.

2. Put Plastic sheet on the mold that acts as the plee ply.

3. Start brushing the gauze pieces with epoxy and layering them on the mold, till you get all the layers together.

Gauze with epoxy

 
adding layers Mold after adding layers
 

3. Put another layer of plastics for avoid mess in the vaccum bag.

4. Put your overall project in the vaccum bag and start pulling out air

Putting the mold in the bag. sucking air.
 

That's how it will look like at the end.

After 12 hours, I checked the bag and it was fully cured. I removed the plastic sheets, and how the product looked like.

 

Now it's time for Coloring! :D

And Finally!

   

Downloads:

1. 3D Mold file.