14. Composites


Fourteenth Assignment:

Contents:

  1. Safety in materials and resins
  2. Mold design
  3. Production of composite materials
  4. Testing
  5. Selft evaluation
  6. File download

Requirement:

  1. Autocad Software
  2. Corel Software
  3. Shopbot Milling machine
  4. Laser cut machine
  5. MDF
  6. plywood
  7. Composite material
  8. Resin

For this assignment, I have to learn about material safety and technical data sheet for the resins that I using. Also I going to design and fabricate a 3D mold and produce a fiber composite part in it

Safety in materials and resins

We have to be very careful, to use some dangerous products, is for this reasons that we have to read their safety data sheet to avoid injuries. For this task i going to use fiber glass and resine, and this materials are dangerous for the health, for more informatión you can read theirs data sheets located in download section.

Fiber glass

Resin


3D mold design

I design the shape of my skate on Autocad 3D to take as reference


For this assignment I decided make my mold in MDF and plywood material and use the shopbot and laser cutter for this I did my design in corel and export in DFX for the Laser cut and shopbot

In the laser cut



Milling Pieces in the shopbot machine





After cutting my materials I proceeded to assemble the pieces made in the Laser cut and shopbot




Assembling of the mold



Gluing, pressing and sand the mold





Production of composite materials

I decided make a flexible skate and for this reason I thought use synthetics jute, and resine to my composite materials.
For the bonding material I used Resin Pox Bak 1206



I used liquid silicone and car wax to prevent jute from sticking to the mold

Then I proceeded to prepare the mixture for this I used the ratio 5:1 for the Epoxy and the hardener, and I proceed to do the composite for the skate board.



Then I proceed to compress the mold and let dry for 24 hours


Finally I extracted, cut and sand the board


Using more composite materials

I made another mold join parts of Plywood to make the mold, this was a very hard work because our fablab Shopbot didn't have long millings to shape the skateboard mold, and I had to do it by hand.


I made another mold join parts of Plywood to make the mold, this was a very hard work because our fablab Shopbot didn't have long millings to shape the skateboard mold, and I had to do it by hand.


You have to take care when you mix the resine, we have to use our personal protective equipment and dont forget the relation 5 to 1 of the resine


To prevent our composite material from adhering to the mold, we will use a released agent (candle)


For my composite I use different thicknesses and types of jute also i'm using fiber glass




After I put layers of jute and fiberglass I compressed the mold with a hevy machine


I lost a lot of time extracting the skateboard from the mold because I did not put much wax.


Testing

Finally I cut and sand the skateboard and did some tests

Self evaluation

  1. What worked:
    • I made my skateboard how I proposed

  2. What did not work:
    • The skateboard don't have the necessary stiffness to support an adult and I had to do another board using fiberglass to have greater hardness

  3. Things to improve:
    • Always use a lot of wax to avoid it from sticking to the mold and Use strong materials for greater hardness

File download