Manufacturing method

To see the manufacturing method of each part, click here

For the manufacturing process, we should consider it in our first stage, the design stage. We need to know how to manufacturing it in order to draft our design. If it cannot be manufactured or the manufacturing method is costly, surely, we need to redesign it.
Before head of the selection of manufacturing process, there is the selection of the material. The selection of a specific material for a particular part or product is an important part of the design and manufacture cycle. It is the responsibility of the design function, not only to design a product that meets the specific need, but also to select the correct material for the part or product. The selection of a specific material ultimately limits the manufacturing processes that can be used ones specified. There is three important factors influence the selection of materials in manufacturing.
1) The product design of our need;
2) Materials with appropriate properties required;
3) Based on both of the above, suitable manufacturing processes that can be used;
Regarding description of materials in term of their properties, there are two distinct property sets to be considered. The first of these are the mechanical properties, which describe how a material reacts under applied loads. The other set is the physical properties of the material such as density and melting point.

For our design, all of our parts are make of metal. It is because we need resist the large torque of the spindle, achieve a high hardness and hold up such a heavy weight, we use different kind of metal for our product and we need to metalworking to working with metals to create individual parts, assemblies, or large scale structures.

When we design of using which kind of metalworking, we need to consider the manufacturing capability. Manufacturing capability refers to the technical and physical limitations of a manufacturing firm and each of its plats. There is several dimensions of this capability can be identified: 1) technological processing capability. 2) Physical size and weight of product and 3) production capacity.
Technological processing capability of a plant is its available set of manufacturing processes. That is, how many kind of manufacturing method or machine we can use. We can not use a milling machine for rolling or use a sand casting foundry for die casting. The technological processing capablilty is closely related to material type. See the chart below:


Compatibility chart of materials versus processes

 

Material

Process

Iron

Steel

Aluminium

Copper

Magnesium

Nickel

Refractory metals

Titanium

Zinc

Sand casting

X

X

X

X

X

X

 

 

0

Permanent mold casting

X

0

X

0

X

0

 

 

0

Die casting

 

 

X

0

X

 

 

 

X

Investment casting

 

X

X

X

0

0

 

 

 

Extrusion

 

0

X

X

X

0

0

0

 

Cold heading

 

X

X

X

 

0

 

 

 

Stamping

 

X

X

X

0

X

 

0

0

Screw machine

0

X

X

X

0

X

0

0

0

Powder metallurgy

X

X

0

X

 

0

X

0

 

Key: X = Routinely performed, 0 = Performed with difficulty, caution, or some sacrifice, blank = Not recommended

 

Physical Product limitations The second aspect of manufacturing capability is imposed by the physical product. A plant with a given set of processes is limited in terms of the size and weight of the products that can be accommodated. Large, heavy products are difficult to move and produce. Larger machines must be used to process larger parts. The production and material handling equipment must be planned for products that lie within a certain size and weight range.
Production Capacity: The third limitation of a plant’s manufacturing capability is the production quantity that can be produced in a given time period and its cost. For the prototype like the project we have done, we don’t need to have a large production capacity but a low initial cost. However, for a large quantity of production, we prefer a high production rate.
Then we can compare which process we can use. Here is a manufacturing table:
manufactroing table

In comparing both traditional machining machine and the Computer numerical control machine, we chose the traditional machining machines to manufacture the parts. The reasons are:
1.    Tolerance can be handled carefully
2.    Limited number of parts was produced and setting up CNC takes time

  1. More traditional machines in the workshop

In the following, EDM wire cut and milling machine are introduced. It is because they are used in the manufacturing process.

EDM wire cut
EDM (electro-discharge machine)is a technique used to produce holes, slots, cavities and complex shapes in electrically conductive material by means of the controlled removal of material through melting of vaporization by high frequency electrical sparks. Wire EDM use a thin wire electrode made by brass with 0.25mm diameter. The wire is continuously spooled like a bandsaw blade passing through a starter hole in the work piece. As the wire is surrounded by de-ionized water approaches the work piece, a spark forms in what is known as the spark gap. Advantage of the EDM wire-cut is its high accuracy (within 0.0025mm). One drawback is that EDM wire-cut need a long time to finish its work.

 

Milling machine
Milling machine is one of the most versatile conventional machine tools with a wide range of metal cutting capability. Many complicated operations such as indexing, gang milling, and straddle milling etc. can be carried out on a milling machine.

This training module is intended to give us a good appreciation on the type of milling machines and the various types of milling processes. Emphasis is placed on its industrial applications, operations, and the selection of appropriate cutting tools.

Cutting tools:

  1. End Mills - Commonly used for facing, slotting and profile milling
  2. Rough Cut End Mills - For rapid metal removal
  3. Slot Drills - For producing pockets without drilling a hole before hand
  4. Face Milling Cutters - For heavy cutting

Spindle speed: Spindle speed is in revolution per minute (R.P.M.) for the cutter and can be calculated from the equation below.
N = CS x 1000 / π d, where N = rpm of the cutter, CS = Linear Cutting Speed of the material in m/min, d = Diameter of cutter in mm

Cutting fluids: It has the same role as that in lathe.