REVERSE ENGINEERING EXPLAINED !!

The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is known as reverse engineering.

Need For Reverse Engineering:

• The original manufacturer of a product no longer produces a product
• There is inadequate documentation of the original design
• The original manufacturer no longer exists, but a customer needs the product
• The original design documentation has been lost or never existed
• Some bad features of a product need to be designed out. For example, excessive wear might indicate where a product should be improved
• To strengthen the good features of a product based on long-term usage of the product
• To analyze the good and bad features of competitors’ product
• To explore new avenues to improve product performance and features
• To gain competitive benchmarking methods to understand competitor’s products and develop better products
• The original CAD model is not sufficient to support modifications or current manufacturing methods
• The original supplier is unable or unwilling to provide additional parts
• The original equipment manufacturers are either unwilling or unable to supply replacement parts, or demand inflated costs for sole-source parts
• To update obsolete materials or antiquated manufacturing processes with more current, less-expensive technologies

Process Of Reverse Engineering:

• Identify the system’s components and their interrelationships
• Create representations of the system in another form or a higher level of abstraction
• Create the physical representation of that system

Reverse engineering is very common in such diverse fields as software engineering, entertainment, automotive, consumer products, microchips, chemicals, electronics, and mechanical designs. For example, when a new machine comes to market, competing manufacturers may buy one machine and disassemble it to learn how it was built and how it works. A chemical company may use reverse engineering to defeat a patent on a competitor’s manufacturing process. In civil engineering, bridge and building designs are copied from past successes so there will be less chance of catastrophic failure. In software engineering, good source code is often a variation of other good source code.

OVERSTEERING AND UNDERSTEERING EXPLAINED !!

Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Simply put, oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occurs when a car steers less than the amount commanded by the driver.

Understeer happens when the front wheels start to plow straight even  if you have the steering wheel turned. Front-wheel-drive cars are  susceptible to understeer because power is being sent to the same wheels  that steer the car, and when the tires start spinning there’s no grip  to steer. If your front tire tread has ever been packed with snow or  mud, you know the feeling of understeer because, as you turn the wheel,  the car keeps going straight. The most common form of understeer is caused by accelerating too soon  in a corner, lifting the weight distribution, and grip, off of the front  tires.  However turning the wheel too fast, and too far, can also cause  understeer.  The steering wheel is most intuitive control in the car.   On the road, below the limit of the car, more wheel equals more  turning.  This is not so at speed.  The tire wants to go straight, so the  more we turn it, the less it actually wants to grip.

Oversteer is the tendency for the rear end to slide out or fishtail.  In responsible everyday driving, there’s no reason oversteer should be a  concern. In rain, snow or mud, however, the rear end of  rear-wheel-drive cars can creep out on you. Traction and stability  control can minimize that fishtailing. The exhibition sport of drifting  is an activity that revolves around oversteer; drivers pitch their  specially-built cars sideways and smoke the tires at high speeds. Fundamentally, the rear end of the car has lost grip, and begins to overtake the front. 

DIFFERENCE BETWEEN MECHANICAL EFFICIENCY AND MECHANICAL ADVANTAGE EXPLAINED !!

We say that machines make work easier b/c they change the size or the direction of the force (input).

Mechanical advantage is a measure of how much your force is multiplied, efficiency is a measure of how much of the work you do actually goes to moving the thing you're trying to move.

Mechanical Advantage = output force

                                      Input force

If your result is :

greater than 1 = the output force is greater than the input force

(this is what you want because you don’t want to put in more force than you get out)

less than one = it requires more input force from you and does not have a mechanical advantage.

It will simply give,that how my input force is greater or lesser than output force.

On the other hand,

Mechanical Efficiency =  work output    X 100  

                                    Work input

This will give you a percentage.It simply tells how well my system 

is working.

Consider a system of pulleys used to lift a heavy load: the pulleys provide a mechanical advantage to let you lift the load more easily, but in addition to moving the load, you also have to move the rope and the pulleys.

Adding more pulleys may increase the mechanical advantage, but it also increases the amount of  extra stuff you're moving.

The more extra stuff you're moving, the less efficient the system.

CHECK OUT WHY MOBILE NUMBERS IN INDIA HAVE 10 DIGITS !! WHY NOT 9 OR 10 !!

Why do we have 10-digit mobile numbers? This is probably something most of us do not really think about. But it has a very sound logic to it. 

The logic: The number of digits in a mobile phone number decide the maximum mobile phones we can have without dialing the country code, ie. 91 (for India). To understand this we need to go back to school. Remember permutations & combinations. Suppose I had a pair of jeans (J1-2) and four tee-shirts (T1-4). The possible combinations are: J1T1, J1T2, J1T3, J1T4, J2T1, J2T2, J2T3, and J2T4, ie. 8 combinations {2 (no. of jeans) X 4 (no. of tee-shirts)}.

The same logic is used when computing the digits in a mobile phone number or for that any numbers such as those for vehicles, land-line telephone numbers, etc. Now suppose if we had a 6-digit cell number, the maximum number of unique cell numbers possible would have been (10 x 10 x 10 x 10 x 10 x 10), ie. a maximum of 1,000,000 subscribers. We have already crossed the 100-million mark in India. So obviously we could not have had a 6-digit cell phone number. Not even a 7-digit because that would've resulted in a capacity of 10 million, not even 8-digit (100 million subscribers), and not even a 9-digit (ie. 1000 million or 100 crore, since our population is close to 125 crore and growing).

A 10-digit cell number offers us a capacity to have 10 billion (1000 crore) subscribers, which is far more than what our country can even achieve. We are v.v.v.unlikely to have a population or a subscriber base of 1000 crore but there is a remote likelihood of us having 100 crore subscribers. Hence, a 10-digit mobile phone number.

TECHNICAL TERMS OF AIR COMPRESSOR !!!

1.)ANEMOMETER – An instrument for measuring the velocity of flow of a gas, either by mechanical or electrical methods.

2.)ATMOSPHERIC PRESSURE – The force exerted by the weight of the atmosphere on every point with which it is in contact.

3.)ECCENTRIC AND STRAP – An eccentric is a disc having its axis of rotation
out of its centre. It is equivalent to a crankpin which is so large in diameter
that embraces the shaft to which it is attached and dispenses with arms.
Converts rotary motion into reciprocating motion.

4.)EFFICIENCY – Ratio of the useful work performed by a prime mover to the energy expended, that is, the output divided by the input.

5.)ENBLOCK CYLINDERS – Two or more cylinders cast integral, that is all in one casting.

6.)FEATHER VALVE – A valve which consists of a strip of ribbon steel which covers a slightly narrower slot when the value is closed.

7.)FINGER VALVES – Valves consist of narrow strips of stainless. fastened to the seat at one end and free to flex along their length. Suitable for light service.

8.)MULTISTAGE COMPRESSION – Dividing the compression of air into two or more stages so as to obtain the work saving due to a nearer approach to isothermal compression by using intercooling.

9.)PISTON SPEED – The total distance travelled by the piston in one minute, not the actual velocity at any given instant.

10.)PORTABLE COMPRESSOR – A small compressor which is easily moved from place to place

7 THINGS YOU DID NOT KNOW ABOUT HYPERLOOP !!

Back in 2013, modern-day Iron Man Elon Musk unveiled his concept for a high-speed transportation system he described as a cross between a Concorde, a railgun, and an air hockey table. Dubbed the "Hyperloop," this futuristic train would theoretically be capable of catapulting passengers at supersonic speeds, up above ground, inside giant tubes. It seemed a little pie-in-the-sky then, and it's still widely misunderstood, so we checked in to see how much progress has been made, and how close we are to ping-ponging cross-country in a flash.

1. It will travel at 800mph

As outlined, the Hyperloop would be capable of traveling faster than the speed of sound. To put that in perspective, a trip on the Hyperloop from LA to SF -- the route initially proposed by Musk -- would take just 35 minutes, compared to a six-hour drive, or hour-plus commercial flight. 

2. The passenger pods float inside giant steel tubes using magnetic pressure. You know those pneumatic tubes at the bank drive-up window that you use to shoot the teller your deposit slip? Imagine that, but big enough to fit a couple dozen passengers, and you've got the right idea. Musk's plan involves using magnets to propel aerodynamic capsules (where the people will sit) through giant steel tubes, sidestepping any friction by keeping it afloat on a constant pressurized cushion of air. 

3. Actual pod concepts will be competing on a Hyperloop test track this year

Based on Elon Musk’s track record, you’d be silly to underestimate him. However, it’s pretty wild how close we are to seeing a real, live Hyperloop in action. Just last month, Musk’s aerospace company SpaceX hosted a competition of 120 teams of high school and college students, challenging them to come up with innovative Hyperloop pod designs (MIT took the top spot, by the way). Additionally, the construction of test tracks in California and Nevada is underway, where the students will test their pod designs later this year.

4. It's self-powering

One of the biggest draws for a Hyperloop, besides speed of course, is that it would be eco-friendly and self-sustaining. The design, as outlined by Musk, involves topping the steel tubes with solar panels, which store the energy that powers the air compressors that cushion the pods, as well as other vital components. Enough energy would be stored so that even at night or in cloudy weather the Hyperloop could continue operating normally.

5. It could only run in a fixed straight line, or else the speed would make you sick

Humans can only handle about 0.2 Gs of acceleration up and down or side to sidewithout turning into walking, talking vomit machines. So essentially, if this thing is rocketing at 800 miles per hour, it will be crucial that it travel along a straight fixed plane. No tubes could go down into valleys or up and across mountains; that means carving a lot of tunnels and constructing giant pylons, which would be hugely expensive. And even under the optimal conditions, moving about the cabin would be incredibly dangerous, especially if it needed to suddenly slow down.

6. Minor malfunctions would be catastrophic When you’re catapulting inside a windowless vacuum at supersonic speeds, even the slightest disruption to the air around it is game over. There would be airplane-style oxygen masks that drop down in the event of a loss of pressure inside the pod, but what about an unexpected jolt from outside the tube (an earthquake, freak explosion, etc.) that cracks the facade? Or what if any of the air compressors that cushion the pod fail? Either of those scenario ends with an out-of-control, train-sized bullet violently bouncing off the walls. That would be bad.

7. It will cost less than you think

According to Musk and others, the Hyperloop route between LA and San Francisco would cost roughly $6 billion to build, which is nearly one-tenth the overall cost of the high speed rail service California has planned. When you put that in perspective with the Hyperloop’s 35-minute one-way trips (compared to the high speed rail’s 180 minute predicted trip time), it sounds like an even more attractive plan. 

WATCH THIS AWESOME PROCESS OF MAKING A GEAR WHEEL !

Have you ever imagined the state of our lives without this smart and most-demanded invention of the wheel? Sheer misery and the life of caves and hunting. The earliest of humans invented it to their greatest convenience, and gears came thousands of years later. This little invention is as old as 27th Century B.C., but now it continues to be an essential part of nearly every piece of machinery we lay our hands on.

Have you ever considered how these disks of gear wheels are made? Also, how those little details and the intricate and fine teeth on the gear wheels are always perfect and precise? It is not as simple as it might sound, and as painstaking as the process might be, it is an absolute treat to watch.

This video might force you to put in more thoughts into the details of the things that we use in our daily lives.