Band Saw Machine, and Non-Traditional Manufacturing (Week 11)

Question 1

What is a Band Saw Machine?

Answer 1

A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material.

Question 2

What are the 4 main components of a Band Saw Machine?

Answer 2

1. Head
2. Column
3. Table
4. Base

Question 3

What is the Cutting Tool of a Band Saw Machine?

Answer 3

Cutting Tool is a Blade (Saw)

Consists of Several Teeth

Can be Used for All Materials

Question 4

Width of the Cut is Called the _________ and is small so the Process Wastes no Material

Answer 4

Width of the Cut is Called the [Kerf (slit)] and is small so the Process Wastes no Material

Question 5

What are Saw Blades made from?

Answer 5

Carbides
High Carbon Steels
High Speed Steels

Question 6

What is the typical function of a Band Saw?

Answer 6

Separate a work part into two pieces and cut off unwanted portions of the part.

Question 7

Teeth have deviated in order to _________________ between the saw blade and part.

Answer 7

Teeth have deviated in order to [reduce Friction] between the saw blade and part.

Question 8

Teeth type depend on the _________________

Answer 8

Teeth type depend on the [cutting material]

Tooth pattern determines the efficiency of a blade in various materials.

Question 9

What tooth pattern is best for cutting most ferrous metals?

Answer 9

Standard Tooth Blade Pattern

Question 10

What tooth pattern is best for cutting aluminum, magnesium, copper, and soft brasses?

Answer 10

Skip Tooth Blade Pattern

Question 11

What tooth pattern is best for cutting most nonferrous metallic materials?

Answer 11

Hook Tooth Blade Pattern

Question 12

What is the Three-Tooth Rule?

Answer 12

At least three teeth must be in contact with the work

• Large sections and soft materials require a coarse-tooth blade.
• Small or tin work and hard materials require a fine-tooth blade.

Question 13

What is the difference between conventional & Nonconventional processes?

Answer 13

Non-conventional technologies refer to a group of processes that remove material NOT using a sharp/hard cutting tool like in conventional machining.

Question 14

What are some other forms of energy used to remove or add material in Non-Traditional Machining?

Answer 14

Electricity
Heat energy
Light energy
electrochemical energy
chemical energy
sound energy
special mechanical energy

Question 15

Why non-traditional technologies is important?

Answer 15

To machine newly developed difficult-to-cut materials: high strength, high hardness, and high toughness.

To machine complex part geometries, micro-surface, and low-stiffness parts. that are difficult or impossible to machine by traditional methods.

To avoid surface damage, such as stresses, created in conventional processes.

Question 16

What is the difference between traditional and non-traditional
machining processes?

Answer 16

Traditional Machining Processes :
Use mechanical energy
Direct contact between the tool and the workpiece
Using a Sharp/Hard cutting tool
High tool wear

Non-Traditional Machining Processes :
Use chemical, electrical, or thermal energy
whereas unconventional machining does not.
NOT using a sharp/hard cutting tool
Minimal tool wear

Question 17

What is Water Jet Machining (WJM)?

Answer 17

It uses a fine, high pressure, high velocity (500-1400 m/s) stream of water (~ Ø0.1- 0.4mm) directed at the work surface to cause cutting of the workpiece.

Cutting of all non-metallic
materials (food, composites,
plastics, fabrics, rubber,
wood, Rocks,…) and all metallic materials.

Can cut any material.

Question 18

Electro-chemical Machining (ECM)

Electrochemical machining removes material from ________________________ workpiece by anodic dissolution. Workpiece geometry is obtained by a formed electrode tool that is in close proximity but separate.

In this process, particles travel from the anodic material (workpiece) toward the cathodic material (machining tool). A current of _________________ carries away the deplated material before it has a chance to reach the machining tool. The produced cavity is the mating image of the tool shape.

Its industrial application has been extended to:
*ECM machining
*ECM drilling
*ECM grinding
*ECM polishing

Answer 18

Electrochemical machining removes material from [an electrically conductive] workpiece by anodic dissolution. Workpiece geometry is obtained by a formed electrode tool that is in close proximity but separate.

In this process, particles travel from the anodic material (workpiece) toward the cathodic material (machining tool). A current of [electrolyte fluid] carries away the deplated material before it has a chance to reach the machining tool. The produced cavity is the mating image of the tool shape.

Its industrial application has been extended to:
*ECM machining
*ECM drilling
*ECM grinding
*ECM polishing

Question 19

Electrical Discharge Machine (EDM)
Basics

The workpiece is removed by a series of sparks that cause localized melting and evaporation of the material in the presence of a ______________.

The workpiece is typically submerged in a dielectric bath of ________________________.

Answer 19

The workpiece is removed by a series of sparks that cause localized melting and evaporation of the material in the presence of a [dielectric fluid].

The workpiece is typically submerged in a dielectric bath of [deionized water or oil].

Question 20

Electrical Discharge Machine (EDM)
How It Works

At the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage __________ an electric field in the insulating dielectric that is present in a narrow gap between the electrode and the workpiece. This causes ______________________ suspended in the dielectric to concentrate at the points of the strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high, the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing a small amount of material from the workpiece surface.

Answer 20

At the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage [induces] an electric field in the insulating dielectric that is present in a narrow gap between the electrode and the workpiece. This causes [conducting particles] suspended in the dielectric to concentrate at the points of the strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high, the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing a small amount of material from the workpiece surface.

Question 21

What is the difference between Dielectric and Electrolyte?

Answer 21

A dielectric should be an electrically non-conductor at normal conditions; however, it should behave as a good conductor after a breakdown.

An electrolyte should be a good conductor of electricity for completing the electrical circuit to allow a smooth flow of ions between electrodes

Question 22

What are the Advantages of (I’m not sure whether this slide was referring to Non-Traditional Machining in general or EDM specifically)

Answer 22

Ability to machine complex shapes that would otherwise be difficult to produce with conventional cutting tools. Also, machining of extremely hard material to very close tolerances

Very small work pieces can be machined where conventional cutting tools may damage the part from excess cutting tool pressure.

There is no direct contact between tool and work piece. Therefore, delicate sections and weak materials can be machined without perceivable distortion.

Tapered holes may be produced, and very fine holes can be attained

Tool wear is zero, same tool can be used for producing infinite number of components.

High surface quality may be achieved.

No direct contact between tool and work material so there are no forces and residual stresses, and less heat is generated.

Question 23

Q. In which of the following industries, Non-traditional machining methods play an important role?

a) Automobile
b) Aerospace
c) Medical
d) All of the mentioned

Answer 23

d) All of the mentioned

Question 24

Q. Non-Traditional machining can also be called as ________

a) Contact Machining
b) Non-contact machining
c) Partial contact machining
d) Half contact machining

Answer 24

b) Non-contact machining

Question 25

Q. Non-Traditional machining is recommended when we need which of the following features?

a) Complex shapes
b) High surface quality
c) Low-rigidity structures
d) All of the mentioned

Answer 25

d) All of the mentioned

Question 26

Q. Different classifications of Non-traditional machining based on source of energy are:
a) Mechanical
b) Thermal
c) Chemical and electro-chemical.
d) All of the mentioned

Answer 26

d) All of the mentioned

Question 27

Q. In mechanical machining, material is removed by ___________

a) Erosion
b) Corrosion
c) Abrasion
d) Vaporization

Answer 27

a) Erosion

a) Abrasive grains remove material by mechanical erosion in USM

Question 28

Laser Beam Machining (LBM)

It uses the _____________ from a laser to remove material by vaporization and ablation. Laser beam melts the material by ____________________________ of ______________________ on the workpiece.

Answer 28

It uses the [light energy] from a laser to remove material by vaporization and ablation. Laser beam melts the material by [focusing a coherent beam] of [monochromatic light] on the workpiece.

Question 29

What is a LASER?

Answer 29

LASER is a device that stimulates atoms or molecules to emit light at particular wavelengths and amplifies that light, typically producing a very narrow beam of radiation.

Question 30

What does LASER stand for?

Answer 30

Light Amplification by Stimulated Emission of Radiation

Question 31

What is Additive Manufacturing (AM)?

Answer 31

Additive manufacturing (AM), also known as 3D printing, is a transformative approach to industrial production that enables the creation of lighter, stronger parts and systems.

Question 32

What is Rapid Prototyping?
Short Version

Answer 32

A CAD technique to allow “Automatic” creation of a physical model or prototype from a 3-D model.

Create a 3-D ‘Photocopy’ of a part. =>Computer → Real life

Question 33

Why use Rapid Prototyping?

Answer 33

• Decreases lead time
• Facilitates concurrent engineering
• Allows visualization of more ideas

Question 34

What is Rapid Prototyping?
Long Version

Answer 34

Rapid prototyping is the use of CAD and additive manufacturing (3-D printing) to create a 3-D model in a short amount of time. The model is usually not made of the same material as the final part and is used to decrease lead time, facilitate concurrent engineering, and allow visualization of more ideas. In other words, designers can use the faster manufacturing process to diagnose issues with the intended part and improve its design without having to make an expensive prototype using traditional manufacturing methods.

Question 35

What do the following phrases mean (in the context of Rapid Prototyping)?

• Decreases lead time
• Facilitates concurrent engineering
• Allows visualization of more ideas

Answer 35

• Decreases lead time: it means less risk, exposure, and management of materials.
• Facilitates concurrent engineering: Concurrent engineering involves the process of bringing together knowledge and expertise from different areas in the early phases of the product development process
• Allows visualization of more ideas: Visualization is the practice of imagining what you want to achieve in the future.

Question 36

Q. Which of the following is correct about ECM?

A. Erosion of metal takes place as a reverse process of electroplating
B. Thermal stresses are induced
C. Mechanical stresses are induced
D. None of the mentioned

Answer 36

A. Erosion of metal takes place as a reverse process of electroplating

Question 37

Q. Which of the following materials cannot be machined using an electric discharge machine?

A. Iron
B. Aluminum
C. Wood
D. None of the above

Answer 37

C. Wood