8. Moulding and casting¶

This week we were introduced to the milling machine, and the different types of materials we can use for casting. we worked in groups and individual.

What is Moulding?¶

is the act of creating the cavity / form that carries a negative or reverse impression of an original model. Molds can be made of a rigid material, such as plaster or plastic resin or more commonly, a flexible material such as rubber. The material to use should be chosen considering the material of the model, the material to be used to make castings, and whether there are any undercuts.

What is Casting?¶

Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process.

Group Work¶

The group assignment was about testing different type of materials used for molding and casting where each two of us was asked to choose a specific type of either molding or casting material from the various types available.

Our work is material 2 which is (silicone rubber).

the material that we used and the safety instructions can be viewed through this link. Click here to view

Individual assignment¶

The first thing to do was to create the design in any 3D design software. I used tinkercad.

I designed a medal for my car as you see in the picture below.

Adding the joint file of the designs after putting them together using TinkerCad this is done to reduce the work time so each two designs are made together at once.

We select the designs and assign the size of the mold as the design is going to be in the middle of the mold we will not be putting the exact dimensions of the mold we would make it less to reduce the work time.

Creating a tool path.

Preview of the design.

Settings of the drill bit where we can choose the size and its type.

Those are the drill bits that we will use.

After making sure everything is ready from the design side we have to set the origin of the CNC machine which is done by lowering the bit until it barely touches the wax that we are going to engrave.

After finishing the engraving we can see that the mold is filled with dust so it has to be cleaned I used water to clean most of it but there is still some fine wax stuck in the details.

I used this stick to clean the fine details of the mold

Measuring in the needed material and since this is silicon we will be using two substances with a 1 to 1 ratio.I made 20.2 by mistake so i have to make part2 same.

20.2 grams of part A