Molding and Casting
1. Design a 3D mold, machine it, and cast parts from it.
Casting.....Wow ..this is my one of the favorite week. This week I made my wax mold and than casted using that mold. The design that I thought to use for molding took me back to the facade design/ or a module that can be repeated and can grow indefinitely in its x or y axis.
I decided to make a mold that can be used for making a pattern. It will have a parameter that it can be developed in either of the axis.
I wanted to make something very fast. The casting should not take more time. So I developed the 3D model of my mold in Rhino.
The module that I have made is of 75 mm by 75mm and the depth of the model is 25 mm at the maximum and 5 mm to the minimum.
The above model shows the possibility to expand and make a monolithic looking pattern at the end.
These are the basic renders for the mold that will be used as the negative part and to create the pieces.
Once the file is made it is converted as .stl file and now taken for the was milling.
Started milling the wax on Roland MDX-20 machine.
The stl file is opened the Roland milling software. and the file is loaded into the software.
Once the file is loaded to the software, now its time to do the setting for the milling of the wax.
First the wax is placed in 0x and 0y position and than the zero of z is set. Once this is done we are ready to mill just after few steps later.
The 1/8 rough cut wax path is selected first and than the .png is formed.
Than the path is made according the the speed and the overlapping distance of the drill bit and the make path button is used to create the cutting path.
Last step is to make .rml file for milling the wax. The file is set through and the speed gives the milling time so we can cross check and see if there is all correct and than the rml file is sent to machine to mill.
Milling of wax is started. Once the milling is done do not remove the wax from its position. The milling is not done yet. Once the first set is done go back to the milling software again and change the 1/8 wax rough to 1/8 wax smooth and do the same procedure again.
Now I had casted the same element with the PU.
After the mold is ready clean it properly and keep it aside and prepare for the casting from that mold.
For casting I am using Smooth-Cast 300 Liquid rubber Compound, that is Tin Cure Silicone Mold Making Rubber actually. This material takes at least 24/30 hours to settle and it turns from a liquid to a solid, durable rubber . It is Ideal for duplicating my wax molds very easily. The casted piece is easily removed from the mold and its clean after the casting. So the same mold can be used for soo many times that we needed.
Once the mold is ready clean it properly and keep it aside and prepare for the casting from that mold.
For casting I am using Smooth-Cast 300 Liquid Plastic Compound. This material quickly turns from a liquid to a solid, durable plastic. It is Ideal for duplicating my wax molds very easily. The Smooth Cast 300 Series of liquid plastics are ultra-low viscosity casting resins that yield castings that are bright white and virtually bubble free
Shake well the bottles before using it.
The liquid plastic is mixed in 50-50 proportions in a plastic glass and stirred well for 2 minutes.
Stir the mixture well till it starts turning into white in color from the transparent color.
Pour the solution into the mold and wait for 5-10 minutes.
Remove the solution from mold.
This is the mold that I got out in 15 minutes.
If the solution is not mixed in equal proportion than the resultant product will not be a strong casted mold as It will be soft and flexible.
It also had few bubbles in it. This was not casted properly and so this was soft and flexible.
There can me many such modules joining to each other to form the panel.
I did the same procedure for 4 times. Fourth time I was surprised to the result as this piece took more than 30 minutes to settle and also it had many bubbles on the back side of the casted piece.
After removing the casted piece from the mold I was surprised to see the result that is like a rubber piece. It was not at all same as the pieces that I had cased earlier. This piece was soo different than each pieces.
It was flexible and also it was having an elastic properties . I think I might have made a mistake in mixing the solutions with each other or it was because of the time to pour the solution in the mold.
Week 12 Files