Week 16: Composite


Individual assignment: Design and produce something with a digital fabrication process (incorporating computer-aided design and manufacturing) not covered in another assignment, documenting the requirements that your assignment meets, and including everything necessary to reproduce it. Possibilities include (but are not limited to) composites, textiles, biotechnology, robotics, and cooking.



The model


I decided to re-model the sword that I did in the week9, but this time I tried to do more details.








I tried to draw the friezes with enough space for the tip, but the work is too long and complicated so I did it in a casual way.




After I was sure that all the lines's friezes were closed I started to extrude them.




Then I did the chamfers of the blade and the hilt.






To finish the hilt I made a simple sketch and after the extrusion I finished it with the fillet function.




Since the foam that we have in the laboratory is 4 cm high and the friezes of the sword are on both sides I decided to mirror and cut it in half, so I have two parts to glue together.










Cut3d



Once I finished the file I exported it to STL and I opened it in Vectric cut 3d (available in our lab's computer). This program realizes the gdcode for Roland milling. The process is the same used for the week 9.

I used this tip for the roughing

and this one for the finishing

Then I saved the two toolpaths


ShopBot

To start the work I screwed the foam to the worktop so that the screws were in the most external position possible


To use the shopbot first of all you have to set the x and y axes

And then the z with the help of a metal plate supplied with the machine (when the tip touches it the current makes contact and the machine stops).

from the Command Consoled of the control application I launched the File -> Part File Load and prompted the file.

Then the machine started to work









I glued the two parts with the vinyl glue and dry overnight




Composite


After studying the situation I decided to hang the sword to cover it at once. in this way I would had only one problem: the time. I screwed a screw to the handle, I tied it to a thread and hanging on a wooden beam (stuck in a door)



then I cut the flax into strips to make the lining



The resin that I used is the Super Sap ONE epoxy, here the site and the datasheet
The A part is the epoxy and the B part is the hardener. The ratio (by volume) between A and B part is 2:1.

Before to started I prepared all the components for the vacuum bag: the perforated film, the breather material and in the end the release film. Everything had to be ready as I had about 25 minutes to apply the resin-soaked material and close it in the vacuum bag.

Since the resin is a very corrosive material and releases toxic fumes it's essential to protect yourself well as you can

once the sword was covered I put it immediately in the vacuum bag and left in place for as long as necessary



The final result

I must say that it was more complicated than I thought, because the flax strips started to lacked and the resin hardened before I could cover some points, but the result is quite satisfying