Archive for September 2011

BALANCING

September 30, 2011
I think this will help you all to understand balancing….

Remote controlled material handling equipment (RCMHE)

September 29, 2011

Prior to the introduction of the so called “Material handling equipment” humans had to perform physical labor to carry out heavy duty tasks. This could be made possible by employing a huge number of workers. However, when the goods came in bulk unloading and loading turned out to be a very time consuming affair. The use of Material handling equipment in logistics has played a significant role in making the loading and unloading activities easier and faster.

Ask yourself the question “Why are ‘Remote controlled’ material handling equipment used?” and almost instantly you arrive at the logical answer that the chief benefit would be allowing personal to control their machine from a safe distance.

Remote control can be achieved by two different modes:

1)     Radio frequency (RF) Signals

RF signals are further divided into two categories.

a)     Narrow-band system  b)  Spread spectrum system.

2)     Infrared light

Infrared method works by transmitting a beam of light

Infrared mode of radio control is preferred over RF signals because of the safety and precision that it offers. Since the infrared method works by transmitting a beam of light, once the beam is out of sight, the beam is obstructed and the controls turn off.  That is, the operator must always be in view of the RCMHE, which in turns aids safety as the full visibility of the operator over the machine is critical. Precise, in the sense that with the use of RF technology there is always a chance of interference with other signals and might lead to accidents, Infrared remote control makes this type of mistake impossible.

Applications:

1)      Transfer of components from one container to another especially fragile objects

2)      Transfer of  hazardous/explosive objects

3)      Operation in high temperature environment

 

Although it is advantages to use RCMHE, proper training for the staff handling the RCMHE is a prerequisite to ensure safe working.

Remote controlled aircraft

September 29, 2011

This mechanical engineering project is about the construction of a flying model of an air craft controlled by a remote control. The materials for construction include light weight materials like wood, plastic and foam.

The tasks included in this working project are:
1. Building the body of the RC plane.
2. Building the RC plane controls.
3. Building the Electronic controls.
rc airplane controls
The four primary controls of an RC plane, collectively called control surfaces, are:

1. Throttle
2. Elevator
3. Ailerons
4. Rudder

The flight of the plane is directed by the movements of these control surfaces. The control surfaces are controlled by small servo motors which are in turn controlled using the remote control.

Even when the plane is made it is not easy to control it without crashing your model several times. So it is better to take a flight video each time you try to fly it, so that if the model is destroyed beyond repair, you may be able to present the video during your project evaluation.

Useful references:

http://www.rc-airplane-advisor.com/
http://www.rc-airplane-world.com/rc-airplane-controls.html

 

Wall Climbing Robot (WCR)

September 29, 2011

You would rather hesitate to do the inspection and maintenance in a typically dangerous environment like the exterior of a tall building or a nuclear facility and pray to God to provide for someone else to do the same. Well, consider your prayers answered! A wall climbing Robot is willing to go through the trouble so that you can still keep smiling!

But, the idea of developing a wall climbing robot is always held back by the mighty force of GRAVITY!

And BEWARE. This won’t be an Easy Project for you. But this definitely is a fantastic Mechanical Engineering Seminar Topic, especially if you can demonstrate how it defies gravity.

You need to move against gravity to accomplish the task. Adhesion is what is required primarily, to help keep the robot firmly on to the wall. Reliable adhesion is a major factor in developing a WCR. Once a proper suction is obtained, locomotion is the next step.  It is also equally important to keep the weight as low as possible so that the effort to stick on to the wall is quite low.

Wall climbing robot

Adhesion is achieved by making use of

  1. Suction cups

Suction cups offer excellent grip (almost upto 1 atm). But, the negative aspect of using a suction cup is that it needs a vacuum pump. Since the vacuum pump is bulky and has high power consumption it is rather difficult to accommodate one in a WCR. Moreover, a suction cup would find itself useless when trying to stick to a rough surface.

2.    Electrostatic  chuck (ESC)

ESC achieves controlled adhesion by means of electrostatic forces.

Mobility is achieved by making use of an electric motor.

With these things in mind, I hope you would have got an insight of the Wall Climbing Robot.

 

Ref: http://spectrum.ieee.org/robotics/robotics-software/wallclimbing-robot-spies

Working model of Hovercraft

September 29, 2011

The idea of making a Hovercraft dates back to 1716 when Emmanual Swedenborg recorded a design, but it was short lived.  In 1870, Sir John Thornycroft filled patents involving air lubricated hulls. And it was in 1959 a hovercraft was built, by Christopher Sydney Cockerell  by discovering the Momentum Curtain theory. Hover craft also called Air cushion vehicle (ACV) travels on any kind of flat surface. It is supported by a cushion of pressurized air.

Design

  • Can be powered by one or more engines
  • Small crafts have a single engine with the drive split through a gear box
  • Usually one engine drives the fan responsible for lifting the vehicle
  • The other forces air from

hovercraft

Working

Two main principles:

1)      Lift

2)      Propulsion

  • A skirt is required to quarantine airflow
  • No contact with ground hence friction is eliminated
  • The shape of the body affects stability
  • All parts are essential for proper working

Parts

1)      Lifting fan: Usually a centrifugal fan is preferred. When rotated air is sucked into the center hole, it is coupled via a gearbox and connected to the engine

2)      Thrust propellers: An aircraft type propeller with variable type pitch blades. Diameter ranges from nine feet to nineteen feet. In bigger crafts the propellers are rotated while in smaller ones, rudders are used.

3)      Skirt: Flexible strip which is fitted below the bottom edges of the plenum chamber. Skirt design is the most sensitive design parameter as it protects the craft and helps to lift it even higher.

hovercraft diagram

In theory hover crafts are simple machines but a plethora of problems exist to make a functioning hovercraft. The plans as well as the design must be flawless. To build a hovercraft one must be well aware of the demands of construction. Only then can one design a hovercraft.

Pneumatic paper cup forming machine

September 29, 2011

Pneumatic paper cup forming machine” is a wonderful project topic for mechanical engineering students.

In a pneumatic system, energy is stored in a potential state in the form of compressed air. Working energy is produced in a pneumatic system when the compressed air is allowed to expand. So, in order to do work, a device is required which is able to supply an air tank with sufficient amount of air at a desired pressure. This device usually happens to be a positive displacement compressor.

Advantages of using a pneumatic machine:

1)    Lower cost than Hydraulic Machines

2)    Works on air which is freely available.

3)    Compact when compared with Hydraulic Machines

4)    Energy can be controlled relatively easily using valves.

 

The procedure for the development of the paper cup has been broken down into 5 stages

Stages of development:

1)      Body Sealing

A Cup fan wall shaped sheet of paper should be first sealed so as to obtain a cone shape.

2)      Bottom inserting

Round pieces which serve as the bottom of the cup is inserted into the cone and sealed

3)      Bottom knurling

Knurling of the excess portion of the cone is done

4)      Rim Curling

Rim curling is done to make the cup end curled.

5)      Dispensing

The finished cups are automatically discharged from machine.

Pneumatic paper cup forming stages

Factors to be taken into account while designing the cup:

1)      Bottom diameter

2)      Top diameter

3)      Height

4)      Bottom knurling height

5)      Side sealing width

Note:

For best results double PE coated paper is used in the development of cups. Since, in one side PU coated paper cups the paper becomes softened and the chances for the beverage to leak out are high.

Electrical Power Generation System Using Railway Track

September 29, 2011

The system includes a power source, such as a power generation device or an external powersource. The power co-generation system includes first and second electrical capacitance portions that are electrically coupled to the power source and that are configured to carry positive and negative charges, respectively. The power co-generation system further includes a biasing device that is configured to separate the first and second capacitance portions with respect to one another. Thus, by varying the distance between the capacitance portions in response to a vehicle on the rail, the capacitance portions cooperate to act as a variable capacitor that facilitates the co-generation of power with respect to the system. That is to say, the mechanical energy of the biasing device is converted into electrical energy for the system.

 

In accordance with another exemplary aspect of the present technique, a method of co-generating power via a vehicle traveling on a rail is provided. The method includes the act of driving first and second capacitor plates with respect to oneanother in response to the vehicle that is traveling on the rail. The method also includes the act of charging the first and second capacitor plates via a power source, such as a power generation device or an external power source. The method  further includes biasing the first and second plates apart from one another, thereby displacing the plates with respect to one another. This displacement changes the electrical capacitance between the first and second plates and, resultantly, increases the electric potential between the first and second plates. In turn, this displacement of the first and second plates facilitates the co-generation of electrical energy from the kinetic and potential energy of the vehicle on the rail.

Reference