WEEK TWELVE
-Mold and casting-
ASSIGMENT: Design a 3D mold, machine it, and cast parts from it
0. DEFINIE THE PROBLEM I want to focus in
and some DATA that justifies why it makes sense to do it
There is a thing I have always wanted to try to make so I took this exercise as an oportunity to do it.What it is about?
Apparetally 1 l. of used oil we threw down the sink can contaminate 1.000 liters of water. It is very expensive and difficult to separate from the water.
But what is more is that is very contaminant and can create a superficial layer making impossible the air flow air which can kill the animals from the river.
So what I wanted to do in this exercise is to make a mold to later pure the recicled oil soap.
The contra-mold I did it with WAX material, the mold with CILICONE and the inside cast with the SOAP experiment
1. PARTS and LIMITATIONS of a TWO PART CILICONE MOLD
1. It has to have CURVE EDGES and ANGLE INGLINATIONS IN THE WALLS in order to remove it easily.
2. Add JOINING TABS. They are normally located in the frame or edges of the mold to press and fit the two parts while casting the material.
3. Add the POURING CANAL. It has to be located in the place that disturb the less in the design.
2. BRAIN STORMING + SKETCHING my idea
2. Making the 3D design with Rhino software.
4. DESIGNING THE MOLD according to the RESTRICTIONS.
CURVE EDGES, FITTING TABS AND POURING CANAL.
One side of the mold
Second side of the mold
5. EXPORT the 3d file in STL format.
6. PROBLEMS in the CNC with the size and details of my design
The amount of little details do not allow me to mill it all at once with 3mm diametre because the bit will overlap the draw. So I had to think in a solution. My solution was to mill the details with a DXF 2D file after milling the main box. With the pocket option.
7. REDESIGNING THE MOLD
first milling
This was the two parts mold I did with Rhino at the end. First without details and in a separete file the details I wanted to engrave.
Software steps to mill a 3D (stl.)file
second milling
And this are the two 2D DXF files details I have used to mill the details. I used the POCKET OPTION in the CNC and used a 2mm diametre in order to be precise.
Software steps to mill a 2D (dxf) file
Cleaning the WAX contra mold with HARD-WAX OIL
SENDING the WAX with the hitting gun.
Preparing all the necessary material to cast the CILICONE inside the contra-mold
Layer of spray to remove it easiy from the mold.
Making the CILICONE and puring it inside the contra mold.
Waiting 16 hours to let the CILICONE cure.
Remove the CILICONE from the contra-mold and finding two bubles with a bad mixture inside. But I decide to use it and continue with the process.
Recover the mold with TAPE in order to reinforce the joining TAPS and prevent the SOAP to scape throught the rail.
Preparing the SOAP.
Waiting 48 hours for the soap to cure.
I put it in a dry and ventilated place in order to dry faster. But it takes 48 hours to dry.
After waiting 48 hours to let the soap cure I opened the mold and I just used half of the mold as a new mold and see if with more air It dries fast.
Files: