Assignement
design a 3D mold, machine it, and cast parts from it
What i am going to do
- I want to make a casted wrist band using rubber .
Courtesy : http://www.technologystudent.com/equip1/poly2.htm
Mould
I had done sand casting in my college days Courtesy : http://www.custompartnet.com/wu/SandCasting : ,now i am going to make a real mould in wax,We are using Machinable Wax for it .
Why Using Machinable Wax?
Machinable Wax is a very hard Wax having High Melting Point specially designed for Machining Applications .
Mould Designing in Rhino
- I designed a Negative Mould in Rhino for my Wrist Band, What is Negative Mould ? You Can easily understand by looking the following picture.
A)Positive Mould b)Negative Mould
Source :http://www.fibre-reinforced-plastic.com/2011_12_01_archive.html
Rhino Designing Screenshots
- :
Yaa, I created a mould design in Rhino , Now it is ready to Export to .STL format for Milling in Modella or ShopBot . Download Rhino File
Milling Mould in Modella
Modella supports STL file thats a new information to me also have an option to convert .STL to .PNG , I used 1/8” Bits for both Rough Cut and Finishing Cut .
Rough Cut and Finishing Cut
- This 2 level cuting method saves energy and time also gives a good finishing , Yaa rough cut removes major portion of the unwanted wax by milling and same time finishing cuts makes smooth and accurate.
-
:
Yaa, Mould is Ready . Next step is Casting.
Casting Process
This is the process of filling mould by which material we want to use ie, Rubber, Silicone,Plastic,Metal etc…
Now i am going to use Silicone Rubber(SORTA Clear 37)
SORTA Clear 37
It is a Water white translucent silicone rubbers which cure at room temperature with negligible shrinkage and feature high tensile and tear strength.
SORTA Clear Part A and Part B:
List of Materials needs for Casting
- 1.Mould
- 2.Sorta Clear 37 :Part A
- 3.Sorta Clear 37 :Part B
- 4.Water
- 5.Plastic Cup
- 6.Wooden Stick
- 7.Aluminium Foil
- 8.Patience :) :) Your Patience will indicate in your final Result .
Process
- 1.First fill your Mould with water and pour that water into a Vaccant Glass (It is for measuring the volume of mould)
- 2.Take Part A and Part B in Glasses (Equal to 1/2 Volume of Mould)
- 3:Mix It(1:1 Ratio)
- 4:Add 1 drop of Coloring Agent(If you need color)
- 5.Pour the mixed material carefully to Mould (Be careful to air bubbles that makes holes in final product)
- 6.Remove Unwanted Material from Mould
- 7.Wait 4 Hours then Open the Mould
Wait 4 Hours to set .
Finished Product
- :
Problem Faced : I designed this bracelet to my hand but after casting shrinkage happen
Solution :
Need to add some shrinkage allowance in mould design.