Fab Academy 2017 at Fab Lab Barcelona By Trinidad Gomez Machuca
Demonstrate workflows used in mould design and construction
Select and apply suitable materials and processes to create a composite part.
For this assignment I was confused because i thought the purpose was to make a hard mold, So in this week, I did a mold in the 3d print and then I made caseine plastics, that is made with milk and vinegar, It was a intersting exercise but at the end it didn't work, it seems it needs to be in specific enviroment otherwise it will fail the final material like in my case, that you can see in my molding and casting assignment. For this assignment, I want to do a surface, so i designed on rhino and then I made a waffle structure of my model for making the mold.
In this grasshopper concept i used for divide the form by layers in the two axis, X and Y so i can have as many pieces as i want, while more a better 3d dimensional form.
After designed the surface, I made the concept in grasshopper to make the waffle structure and then I join all the pieces.
For making the composites exercise, you need to put a lot of layers of different materials. in this link you can see a very good diagram with the order of the different kind of textiles and make a strong surface with the expoxy material.
1._ Plastic to protect the model-
2.- Hard Fabric (in my case i used the brown one) this layer is the one that is going to be epoxi.
3.- The brather one (blue one)
4.- The breather one.(white one).
5.- Plastic one, to protect the machine.
For using the epoxi you need to mix two chemicals, Part A and Part B. One is the epoxi and the other one is the hardener that is going to detonate the material, for this you have to be very carefully when you mix it, The mix ration for the casting is 2 Epoxy resin and 1 Hardener. Dont forget to use gloves and mask, it smell horrible.
Epoxi is the best material to use for making strong pieces for fabrication. There is always two bottles the part A and the part B. The smell is very strong so, you have to be very carefull when you mix it. Here you can find the Epoxi datasheet
Here we got a weight machine for measure the quantities of the two part of the epoxi. Mix them very well with gloves and Mask.
With a brush I put the epoxy over my textile or the strong layer and finally the rest of the layers.
In the last step, we have to vacuum the form with this we can have a better way to have a nice form. The htermoformer from the lab is broken so for this exercise we have to use a conventional vacuum machine. We bough a spetial bag in the chinece store for packaging thing and save space.
Here you can see how we put our models inside the plastic bag and then how we use a conventional vacuum machine.
After one night inside the vacuum bag, I took my piece and this is how it looks. It took the shape of my final form and as you can see in the video, it is a strong piece. This is the first time i worked with epoxy, I have migraine and the smell is not good at all for me but I liked a lot this exercise even though I did it in the last week very fast because after i saw the result i have a lot of ideas for making bigger prototypes and is a new way of fabrication.
//Rhinoceros
//Grasshopper
Fab Academy 2017 | Fab Lab Barcelona | Trinidad A. Gomez Machuca |
IAAC | trinidad.gomez@iaac.net | |