INTRODUCTION TO METAL CUTTING

Metal cutting is the process of producing a job by removing a layer of unwanted material from a given workpiece.

Fig. shows the schematics of a typical metal cutting process in which a wedge shaped, sharp edged tool is set to a certain depth of cut and moves relative to the workpiece.

Under the action of force, pressure is exerted on the workpiece metal causing its compression near the tip of the tool. The metal undergoes shear type deformation and a piece or layer of metal gets repeated in the form of a chip. If the tool is continued to move relative to workpiece, there is continuous shearing of the metal ahead of the tool. The shear occurs along a plane called the shear plane.

All machining processes involve the formation of chips; this occurs by deforming the work material on the surface of job with the help of a cutting tool. Depending upon the tool geometry, cutting conditions and work material, chips are produced in different shapes and sizes. The type of chip formed provides information about the deformation suffered by the work material and the surface quality produced during cutting.

Types of Chips:

Continuous chips: While machining ductile materials, large plastic deformation of the work material occurs ahead of the cutting edge of the tool. The metal of the workpiece is compressed and slides over the tool face in the form of a long continuous chip.

Discontinuous (segmented) chips: A discontinuous chip is a segmented chip produced in the form of small pieces. The discontinuous chips are produced when cutting brittle materials like cast iron, bronze and brass. The working on ductile materials under poor cutting condition may also sometimes lead to the formation of discontinuous chips.

Continuous chips with built-up-edge: The term built-up-edge refers to the small metal particles that stick to the cutting tool and the machined surfaces as result of high temperature, high pressure and high frictional resistance during machining. The building up and breaking down of the built-up-edge is periodic; its size first increases, then decreases and again increases-the cycle gets repeated rapidly.

ANANTHU GOPINATH

SLOTTING MACHINE

The slotting machine is a reciprocating machine tool in which, the ram holding the tool reciprocates in a vertical axis and the cutting action of the tool is only during the downward stroke.

Construction

The slotter can be considered as a vertical shaper and its main parts are:

1. Base, column and table

2. Ram and tool head assembly

3. Saddle and cross slide

4. Ram drive mechanism and feed mechanism.

The base of the slotting machine is rigidly built to take up all the cutting forces. The front face of the vertical column has guide ways for Tool the reciprocating ram. The ram supports the tool head to which the tool is attached. The workpiece is mounted on the table which can be given longitudinal, cross and rotary feed motion.

The slotting machine is used for cutting grooves, keys and slotes of various shapes making regular and irregular surfaces both internal and external cutting internal and external gears and profiles The slotter machine can be used on any type of work where vertical tool movement is considered essential and advantageous.

The different types of slotting machines are:

1. Punch slotter: a heavy duty rigid machine designed for removing large amount of metal from large forgings or castings

2. Tool room slotter: a heavy machine which is designed to operate at high speeds. This machine takes light cuts and gives accurate finishing.

3. Production slotter: a heavy duty slotter consisting of heavy cast base and heavy frame, and is generally made in two parts.

Goals of Networks & advantages and disadvantages of networking

Fahad V S IT ,

Networks

Computer Network means an interconnection of autonomous (standalone) computers for information exchange. The connecting media could be a copper wire, optical fiber, microwave or satellite.

Networking Elements – The computer network includes the following networking elements:

At least two computers
Transmission medium either wired or wireless
Protocols or rules that govern the communication
Network software such as Network Operating System

Network Criteria:

The criteria that have to be met by a computer network are:

1. Performance – It is measured in terms of transit time and response time.

Transit time is the time for a message to travel from one device to another
Response time is the elapsed time between an inquiry and a response.

Performance is dependent on the following factors:

The number of users
Type of transmission medium
Capability of connected network
Efficiency of software

2. Reliability – It is measured in terms of

Frequency of failure
Recovery from failures
Robustness during catastrophe

3. Security – It means protecting data from unauthorized access.

Goals of Computer Networks: The following are some important goals of computer networks:

Resource Sharing –

Many organization has a substantial number of computers in operations, which are located apart. Ex. A group of office workers can share a common printer, fax, modem, scanner etc.
High Reliability –

If there are alternate sources of supply, all files could be replicated on two or, machines. If one of them is not available, due to hardware failure, the other copies could be used.
Inter-process Communication –

Network users, located geographically apart, may converse in an interactive session through the network. In order to permit this, the network must provide almost error-free communications.
Flexible access –

Files can be accessed from any computer in the network. The project can be begun on one computer and finished on another.

Other goals include Distribution of processing functions, Centralized management, and allocation of network resources, Compatibility of dissimilar equipment and software, Good network performance, Scalability, Saving money, Access to remote information, Person to person communication etc.,

Advantages and Disadvantages of Computer Networking

Computer network is defined as a set of interconnected autonomous systems that facilitate distributed processing of information. It results in better performance with high speed of processing.

Advantages of Network:

These are main advantages of Computer Networks:

Central Storage of Data –

Files can be stored on a central node (the file server) that can be shared and made available to each and every user in an organization.
Anyone can connect to a computer network –

There is a negligible range of abilities required to connect to a modern computer network. The effortlessness of joining makes it workable for even youthful kids to start exploiting the data.
Faster Problem solving –

Since an extensive procedure is disintegrated into a few littler procedures and each is taken care of by all the associated gadgets, an explicit issue can be settled in lesser time.
Reliability –

Reliability implies backing up of information. Due to some reason equipment crash, and so on, the information gets undermined or inaccessible on one PC, another duplicate of similar information is accessible on another workstation for future use, which prompts smooth working and further handling without interruption.
It is highly flexible –

This innovation is known to be truly adaptable, as it offers clients the chance to investigate everything about fundamental things, for example, programming without influencing their usefulness.
Security through Authorization –

Security and protection of information is additionally settled through system. As just the system clients are approved to get to specific records or applications, no other individual can crack the protection or security of information.
It boosts storage capacity –

Since you will share data, records and assets to other individuals, you need to guarantee all information and substance are legitimately put away in the framework. With this systems administration innovation, you can do the majority of this with no issue, while having all the space you requirement for capacity.

Disadvantages of Network:

These are main disadvantages of Computer Networks:

It lacks robustness –

If a PC system’s principle server separates, the whole framework would end up futile. Also, if it has a bridging device or a central linking server that fails, the entire network would also come to a standstill. To manage these issues, gigantic systems ought to have a ground-breaking PC to fill in as document server to influence setting to up and keeping up the system less demanding.
It lacks independence –

PC organizing includes a procedure that is worked utilizing PCs, so individuals will depend a greater amount of PC work, rather than applying an exertion for their jobs that needs to be done. Beside this, they will be subject to the primary document server, which implies that, in the event that it separates, the framework would end up futile, making clients inactive.
Virus and Malware –

On the off chance that even one PC on a system gets contaminated with an infection, there is a possibility for alternate frameworks to get tainted as well. Infections can spread on a system effectively, in view of the between availability of different gadgets.4. Lack of Independence
Cost of network –

The expense of executing the system including cabling and equipment can be expensive.

PC systems administration will dependably be a quick and advantageous methods for exchanging and sharing data, yet individuals ought to know about its outcomes too.

Networking Concepts! Are they Real?

Fahad V S IT ,

Let’s experiment with Networking

Most of us have studied Computer Networks in a very abstract manner. In other words, not many of us know how the abstract concepts of layers and packets translate in real life networks such as the Internet. Therefore let us do an experiment and see whether these layers, packets etc. exist in any real network also. So get, set and ready to delve into this wonderful world of practical and experimental Networking!

The outline of our experiment is as follows. We will capture some live packets, and to understand what is inside those packets, we will analyze those packets by dissecting them.

To start with, we need to have a PC running Windows XP and connected to the Internet. If you are reading this article online, the chances are high that you have everything ready to experiment. Now let’s recall some of the theory stuff that we read in Networking Books. The first thing that almost every book tells us – networking architecture is layered; remember that 7 layer OSI protocol stack! So where are these protocol layers? In our experiment, we will use 5 layer Internet Protocol stack so that we can solve the mystery of these layers.

We start our experiment by installing Wireshark (earlier known as Ethereal). Wireshark is a Network Protocol Analyzer that can capture and analyze the packets transmitted/received via a Network Interface Card (NIC). [You need to bear with me this acronym because Networking is full of acronymsJ] We install Wireshark from http://www.wireshark.org/download.html (at the time of this writing, the latest Wireshark version is 1.0.3). While installing Wireshark, leave the default settings/options as it is. Now our experimental setup is ready. Run Wireshark and click on the first icon (List the available capture interfaces …). Now we see a pop up window that shows Capture Interfaces. See the snapshots as follows.

The number and types of interfaces shown in Capture Interfaces window can be different for you depending on your PC’s configuration. For me it shows two interfaces and my Internet connection is through Broadcom Gigabit Interface. So choose the interface through which your Internet connection is available to you. Now let’s click on the Options button of this interface. Now we see a new window named Capture Options. In this window, type “port 80” in text field named Capture Filter. See the following snapshot for clarification.

Now we are ready to capture the packets passing through our NIC. By setting the filter to “port 80”, we have instructed Wireshark to capture only those packets that are because of http traffic (remember that we were always told that the default http port is 80!). Now click on the Start button on Capture Options window. You may see some packets in Wireshark if any program in your PC is accessing http traffic in the background; let’s not focus on that. Now open your browser and try to access http://google.com and now you should be seeing lot many packets getting captured in Wireshark. See the snapshot as follows.

Let’s start analyzing the captured packets. First of all, find the first instance of http packet that has GET / HTTP/1.1 in its Info field. In the above snapshot, it’s shown in blue. If we take a closer look, we see that this packet has the headers of the all the 5 layers of the Internet Protocol stack.

Layer 1 – It is the Physical layer. Here Frames are shown at the physical layer.

Layer 2 – It is the Data Link layer. In this packet, we can see that Ethernet II is used as data link layer protocol. We can find the MAC address of the source and destination in this header.

Layer 3 – It is the Network layer. In this packet, we see that IP is used as Network layer protocol. We can see the source and destination IP in this header.

Layer 4 – It is the Transport layer. In this packet, TCP is used as Transport layer protocol. We can find the source and destination ports in this header.

Layer 5 – It is the Application layer. In this packet, HTTP is used as Application layer protocol.

Let’s explore one of the layers. Other layers can be explored further in the similar fashion. If we expand the Layer 5 i.e. HTTP header, it looks as follows.

Here we see that Host is mentioned as google.com that is what we tried to access from browser. User Agent field of the HTTP header shows the browser details. In my case, it is Mozilla Firefox as evidenced from this header. Destination IP 64.233.187.99 should be one of the IP addresses assigned to Google server where the web server is hosted. It can be verified using a very handy utility command “nslookup”. The details of the other fields can be explored in the headers of the HTTP, TCP, IP, Ethernet II protocols. Some of the interesting fields are – Differentiated Services Field (also known as QoS field) in IP header, Window size in TCP header etc.

So we have seen that all those rhetorical concepts of layers etc. do exist in real networks also. And it sounds interesting when you dissect all the packets that pass through your interface card. By doing so, you can get to know what goes/comes through your PC!

The idea of this experiment is to provide a conducive platform so that you can explore your own the exciting world of Networking. So welcome aboard!

Frequently Asked Questions

KIHRD Online Learning FAQ'S ,

B.Voc - Bachelor's of Vocation

1. How long the course run

B.voc programs typically last one to 3 years.

2. Where is Tiss Located

V.N. Purav Marg, Eden Gardens, Deonar, Mumbai, Maharashtra

3. What are the timings of kihrd centre for admissions?

KIHRD Centre for admissions remains open between 9 a.m. And 5 p.m. (IST), Monday through Saturday, with the exception of major Indian holidays.

4. Hostel accomodation

KIHRD provide hostel accommodation with all standard civic amenities and and laundry areas. You should submit your request as soon as possible, because requests are processed on a first-come, first-serve basis, and rooms fill up quickly.

5. Should I apply early?

depends. If you are sure about which course you want to attend, early decision or early action might be the best choice for you.

6. What is TISS SVE?

The approach adopted by TISS-SVE is called the Work Integrated Training Programme (WITP). This Vocational Educational Programme is being implemented for the first time in India with a focus on job-specific skills rather than providing only a broad based education.

7. What is BVoc program?

The Commission also launched another scheme of bvoc Degree programme to expand the scope of vocational education and also to provide vertical mobility to the students admitted in Community Colleges for Diploma programmes to a degree programme in the Universities and Colleges

8. Is B Voc a professional course?

Bachelor of Vocation (B.Voc) is a three year degree course just like B.SC. It can be done in various subjects like interior designing, software development etc. This course is concentrated on making the students “ready to work” for different industries enhancing their employability

9. What is B Voc?

The University Grants Commission (UGC) has launched a scheme on skills development based higher education as part of college/university education, leading to Bachelor of Vocation (B.Voc.) Degree with multiple exits such as Diploma/Advanced Diploma under the NSQF. The B.Voc

10. Is Tiss a deemed university?

The Tata Institute of Social Sciences (TISS) which was established in 1936 is a Deemed University fully funded by the University Grant Commission (UGC), Government of India

11. Is an associate degree better than a certificate?

A certificate is usually two years or less of courses designated by a department. ... An associate degree requires additional general education, Math, and writing courses to round out the program. Associate degrees may be in a career/technical field or for university transfer.

12. Does private university require Aicte approval

If you are studying in a deemed university or in CAMPUS of university(not in its affilated colleges) approved by UGC, then even if your course is not approved by AICTE, it will not create any problem. This is because universities do not require AICTE approval compulsorily.

Battery Electric Vs Hydrogen Fuel Cell: Efficiency Comparison

KIHRD Online Learning Auto News , Automobile

Let’s talk about the Hydrogen drive

Volkswagen recently released a quite interesting comparison of the battery-electric (BEV) and hydrogen fuel cell (FCV) path to zero-emission mobility. The conclusion is that the only way to go for passenger cars is battery-electric cars.

But let's see the details and explain the differences between BEVs and FCVs.A BEV is equipped with a relatively large rechargeable battery, which supplies electricity to the inverter and then electric motor. In the case of FCVs, the battery is very small because it works only as a buffer between the power electronics/motor and the hydrogen fuel cell. The fuel cell stack provides electricity, consuming hydrogen, stored in tanks at high pressure.

When comparing the BEVs with FCVs, Volkswagen refers to studies, which say that hydrogen fuels (as well as synthetic fuels) will remain more expensive than driving all-electric (BEV). The reason for that is simple: more energy is required to produce them (compared to electricity and charging).

Moreover, the greener the electricity is the higher the advantage for BEVs. FCVs turn out to be "very inefficient – both in terms of efficiency and operating costs".

The only light in the tunnel for FCVs is maybe long-distance heavy-duty vehicles, as well as in rail, air and sea transport - but it's not yet proven commercially. Battery electric trucks are also coming.

"Science is largely in agreement on this issue, as several recent studies have shown. The Federal Ministry for the Environment, for example, assumes that hydrogen and synthetic fuels, so-called e-fuels, will remain more expensive than an electric drive, as more energy is required for their production.The Agora Verkehrswende (traffic transformation) initiative also points out that hydrogen and e-fuels do not offer ecologically sound alternatives without the use of 100 percent renewable energies, and that, given the current and foreseeable electricity mix, the e-car has by far the best energy balance. In the view of the Fraunhofer Institute, synthetic fuels and drive technologies such as hydrogen in combination with the fuel cell will indeed play a role – but not so much in the passenger car sector, but rather in long-distance and heavy-duty traffic, as well as in rail, air and sea transport. These segments will only be converted in later phases of the energy turnaround, i.e. beyond the year 2030, and closely linked to the expansion of renewable energies."

"In fact, hydrogen-based fuel cell technology has one crucial disadvantage: it is very inefficient – both in terms of efficiency and operating costs. This is also confirmed in detail by a Horváth & Partners study, comparing both types of drive for e-cars from the customer’s point of view."

Dr. Frank Welsch, Member of the Board of Management of the Volkswagen Passenger Cars brand with responsibility for Technical Development said:

„If we want to take the mobility turnaround and the environmental goals seriously, we must focus on the battery-electric drive. Everything else is a waste of the limited regenerative energy."

Efficiency comparison

According to studies, all-electric cars can achieve an outstanding overall Well-to-Wheel efficiency of 70-90%, depending on a particular example.

"In its study “Automotive Industry 2035 – Forecasts for the Future”, the management consultancy recently had a detailed investigation carried out into whether battery- or hydrogen-powered e-cars will become established in the future. The study was prepared over six months, accompanied by 80 people/interview partners and financed by the management consultancy itself. “The main reason for our study was that Horváth & Partners serves many clients in the automotive supply industry. Of course, these clients want to know what to expect in the next 10-to-15 years,” says study director Dietmar Voggenreiter, explaining the report.

So which energy storage system has the best efficiency and is the most cost-effective for powering electric cars? With battery-powered e-cars, only eight percent of the energy is lost during transport before the electricity is stored in the vehicle’s batteries. When the electrical energy is converted to drive the electric motor, another 18 percent is lost. Depending on the model, the battery-powered e-car thus achieves an efficiency of between 70 to 80 percent."

The hydrogen fuel cell requires 2-3 times more energy to drive the same distance, as the overall Well-to-Wheel efficiency is from 25-35%.

"In the case of the hydrogen-powered e-car, the losses are much greater: 45 percent of the energy is already lost during the production of hydrogen through electrolysis. Of this remaining 55 percent of the original energy, another 55 percent is lost when converting hydrogen into electricity within the vehicle. This means that the hydrogen-powered e-car only achieves an efficiency of between 25 to 35 percent, depending on the model. For the sake of completeness: the efficiency is even worse with alternative fuels. The overall efficiency here is only 10 to 20 percent.

In concrete terms this means that a hydrogen car consumes two to three times more electricity for the same distance than a battery car. But we cannot afford this kind of energy waste. The scarce green electricity must be used as efficiently as possible in the future. Hydrogen would therefore be a serious mistake for passenger cars. “In addition to the very real potential of green hydrogen, there is a dangerous hype going on right now," warn experts from the Boston Consulting Group (BCG) in a study quoted by the Handelsblatt. The Horváth&/Partners study comes to the same conclusions.

However, hydrogen offers very promising prospects – although not for cars. The authors of the study conclude that investments should rather focus on other areas where they make ecological and economic sense. “We believe that there is great potential if green hydrogen is pushed into applications where it can really establish itself in the long term. Above all in industry, but also in heavy-duty transport, aviation and shipping,” says Frank Klose, co-author of the study."

The conclusion

As we many times pointed out over the years, hydrogen fuel cell cars have three serious drawbacks:

· high initial cost of the vehicles (higher than battery-electric)

· high fuel cost (higher operational cost than battery-electric)

· lack of refueling infrastructure (BEVs at least have some in form of home charging, which covers most of the daily charging needs)

The FCV's advantage of range is shrinking as batteries are getting more energy-dense. Moreover, if you don't have a refueling infrastructure nearby, you have to go to a certain hydrogen station - not necessarily along the route, which cost time and... range. So basically there is no range advantage in practical use.

"From every angle of the environmental balance sheet, everything speaks for the battery-powered e-car. The technology is mature and ready for the mass market. The number of models is growing steadily. And with the battery-powered e-car, driving remains affordable. Current e-models are already at the price level of comparable combustion engine models. In contrast, the hydrogen car will always remain more expensive than the battery car – due to the complex technology and high fuel costs. Drivers already pay around nine to twelve euros per 100 kilometers for a hydrogen car, while battery cars cost only two to seven euros per 100 kilometers (depending on electricity prices in individual countries). And the topic of long-distance travel? That will soon no longer play a role. With the new generation of e-cars, ranges will increase to 400-to-600 kilometers, while charging will become increasingly faster."

Carburetor in Bikes & Fuel Injection

KIHRD Online Learning Auto News , Automobile

Carburetor in Bikes & Fuel Injection

Carburetor in bikes

Beginning 1 April 2020, India will move from Bharat Stage IV (BSIV) to Bharat Stage VI (BSVI) emission norms to mitigate the rising pollution in the country. The move from BS4 to BS6 emission standards are so strict that the mechanical changes to two-wheelers or bikes are far more extensive. The BS6 emission norms are so extreme that accurate fuelling is important. Most bike manufacturers have ditched the affordable carburetor to a more precise, but expensive fuel-injection system.

However, what is the difference between fuel injection and carburetor in bikes? In this article, learn about the different fuelling systems of bikes.

Difference Between Carburetor and Fuel Injection:

Since the invention of the internal combustion engine, automobile engineers have strived to find effective ways to deliver air and fuel to the combustion engine. The device which controls the ratio of air-fuel mixture entering the engine is known as a carburetor, a fuel injection system also does the same. Then what is the difference between carburetor and fuel injection?

In simple terms, a carburetor helps the air-fuel mixture to enter the combustion chamber.This method is known as Carburetion All this is done through mechanical parts. The fuel injection system also helps the combustion chamber to get air-fuel mixture, but with the aid of electronics and sensors, and not through mechanical parts.

Carburetor Engine: How Does It Work

The primary job of a carburetor is to mix fuel and air in a certain ratio and feed it to the combustion chamber. The device intercepts the flow of air to the combustion chamber, mixes fuel and delivers it to the engine. When the throttle of the bike is squeezed, the airflow to the carburetor increases causing suction of air and the delivery of fuel increases accordingly resulting in increased acceleration.

In technical , think of the carburetor as a tube that regulates or rather restricts the fuel delivery to increase the velocity of the air. This part which restricts the fuel is known as Venturi. With the increase in velocity of air, a low-pressure space is created, which facilitates drawing of fuel from a jet located near the venturi. This creates a concoction of air-fuel mixture that burns inside the combustion chamber. This is known as the Vacuum Venturi Effect.

Advantages of Carburetor:

While fuel injection systems may have replaced the conventional carburetors, there are advantages of carburetors as well. Below are the advantages:

· They are less expensive and can be easily repaired or replaced.

· Users can tune the carburetor according to their requirement, more power or more mileage.

· Made of light materials and hence are generally long-lasting.

· They are integrated separately from the engine, hence they can be easily removed and serviced or replaced without impacting the engine.

Disadvantages of Carburetor:

Some of the reasons why carburetors have made way for fuel injection systems are due to its disadvantages. Here are the disadvantages of a carburetor:

· Not fuel-efficient as a fuel injection system.

· There is a certain amount of lag resulting in a slow response from the throttle body.

· Carburetors parts are prone to wear and tear which requires frequent replacements.

· The mixture ratio of air-fuel might not always be the same and needs to be tuned regularly.

· Possibility of dust entering the carburetor’s chamber resulting in blockages.

· Diaphragm components are delicate which can be prone to damage easily.

Fuel Injection (FI): How Does It Work

Fuel injection system comprises a complex set of electronic components and sensors. The system depends on a fuel pump to control the flow of fuel to the combustion chamber. This fuel pump is located inside the fuel tank of the bike. The supply of fuel to the combustion chamber is enabled through an Electronic Control Unit (ECU). This electric brain constantly monitors and makes complex calculations to deliver the best possible air-fuel mixture.

The complex calculations include parameters such as throttle position, engine speed, engine temperature and load, among others. The nozzle of the fuel injection system goes right into the chamber of the cylinder. Hence, the ECU directs the injectors to control the amount of fuel to enable the most efficient mode of combustion.

Advantages of Fuel Injection:

Here are the advantages of fuel injection system on bikes:

· Accurate air-fuel mixture and atomisation.

· Cleaner and more efficient combustion.

· Sharper and quicker throttle response.

· Better fuel efficiency or mileage.

· Compared to carburetors, FI systems are maintenance-free and less prone to damages.

· Can easily be tuned through ECU mapping.

Disadvantages of Fuel Injection:

However, fuel injection systems also have disadvantages. Here are some of the advantages of FI:

· Expensive compared to conventional carburetors.

· Requires complex tools to tune the FI system through custom ECU mapping.

· Needs expensive tools to repair it, which leads to higher costs.

· If the ECU fails, the bike will not start and you might be left stranded.

Carburetor Vs. Fuel Injection Engine in Bike: Which is Better

· Versatility: Carburetors are phased out since they are comparatively more pollutant compared to FI systems.

· Performance: The ECU is constantly working on complex calculations to offer the best performance of the engine. The carburetors struggle when it comes to ever-changing fuel temperature and air pressure.

· Mileage: FI system provides an accurate measurement of fuel and air resulting in higher performance of the engine which leads to better fuel management and mileage. The ECU can be mapped for a higher power ratio if you require.

· Maintenance: This is the only category where the carburetor is better compared to the fuel injection system. Carburetors can easily be repaired or replaced while FI systems require professional help which can lead to higher costs.

So, which is better? Fuel injection has an upper hand when it comes to performance, fuel efficiency, and better throttle response. While the FI system may cost you more, the long-term aspects of the FI system are better than a carburetor. That said, old school auto enthusiasts swear by the carburetor technology as they like to fiddle and work on them to derive the required results.