My Project

Molding and Casting with 3D Machining

Molding:

A mold can be made out od any organis or object using any type of material.
Common materials include polymers, plaster, concrete, plastic, epoxy resin, polyurethane rubber, polyester resin etc...
A mold is a slo an art form that precedes a cast.

Casting:

Cast is made by filling the casting material into or onto a mold.
A cast can be made with the same materials that are used in making a mold

Molding and casting have two different methods of creating a mould

The two methods that we were taught are:

1. Master (3D machining) being positve and hard
Silicone Mould being negative and software
Resin Cast being positve and soft

2. Master/Mould (3D Machining) being negative and hard
Cast (Silicone) being positveand soft

Assignement:

For this assignment we will be using the Master,Mold,Cast method.

Master	Rigid foam (blue)
Mould	Silicone Rubber RTV 620 Mixing ratio from the Material Safety Data Sheet
Cast	Smooth On-Smooth Cast 300

I will be using Fusion360 to make my resin cast, I have decided to make my chinese surname character 云(yun). I have to design it in the negative point of view

First I make a box that is 80x80x25 mm with a thickness of 5mm
After that I put the chinese character inside the box
Than I make the background for the characters by cutting a square around it
Lastly I round the corners of the character
Fusion360

Generating G-Code

Hover the mouse over the box at the top left that says design and click on Manufacture
Create a new set up for the toolpath
Go to 3D and click on Adaptive clering
Next, I set the correct parameters
Tool
After finish setting up, I took a look at the simulation to make sure everything is in correct order
After making sure everything is in order, click on setup , create NC program and inside there select the proper post processor and file name The post processor can be downloaded from autodesk
After downloading the post processer I can go into the post library and import the NC code

After generating the NC Code I can move on to milling.

Setting up

Before I even start milling the mould I will have to cut out a blue foam base on the size i set in fusion360 (80mm x 80mm) and mark the center spot.
Apply double sided tape to the back of the blue foam and find a flat surface on the milling machine to place it
Put in the correct tool, load the NC code and Set X,Y,Z axis

After making sure all the settings is correct I can proceed to cutting

Machining

Cutting it down to size before cutting the inside. It goes in a circle at the top
Than the square shape for the inside
After that it process to cut the name
Finished Resin cast

Applying Silicon Rubber RTV-620

We will be using the Silicon Rubber RTV-620 and base on the Material Safety Data Sheet, the mixing ratio is 1 : 1
After considering the size of my resin cast I have decided to use 40grams for both part A and B. Before pouring in the Silicon rubber I first have to place the cup on the measuring scale than set it to zero
Part A and Part B will be poured into separate cups
After I am done pouring I can start mixing them together by pouring A into B
Once I feel that it have been well mixed I can proceed to pur it into the resin cast
Than I let it cure over the week