MECHANICAL ROCKS

INTRODUCTION     The above figure shows the spray-up process.      It consists of fibre, chopper, mould etc...      Spray-up is an open moulding , composite fabrication process where resin and reinforcement are sprayed onto a reusable mould.   Working      First we cut the continuous fibres by help of chopper.      Then a mixture of fiber and resin along with catalyst is sprayed simultaneously onto a vertical mould.      The density of deposited laminate is later increased with the help of a roller by removing the entrapped air.      Multiple layers may be added to produce the desired thickness.      Curing is usually at room temperature but may be accelerated by the application of a moderate amount of heat.                                       

  INTRODUCTION Pultrusion process is the type of closed mould processes. It is used for producing fiber reinforcement plastic of constant cross section such as I-beam, tube, pipes etc. The above figure shows that Pultrusion process. It consists of roller, tank which containing plastic resin, heated die and soon. WORKING Fibres are drawn from spools through uncured resin bath for impregnation. Then impregnated fibres are first fed into a pre-forming box which gives appropriate orientation to the fibres. These oriented fibres are then fed into a heated steel die, where polymerisation and curing takes place, and also determines the cross section of composite stock. After that pulling operation.(continuous length of consent cross-section can be drawn through die.  Reinforcement used in Pultrusion E-Glass, S-Glass /Carbon /Graphite/Aramid reinforcement are used.The forms either roving or mat or fibres. R

INTRODUCTION ·        It is the method of production of  fiber -reinforcement plastics. ·        It is the open mould process. ·        It is the simple and oldest method. ·        There is virtually no limit to the size of the part that can be made. ·        The mould can be made of wood, sheet metal, plaster and FRP composite. ·     Working ·        In order to produce a composite by using glass fibres and polyester resin, a gel coat is first applied to the open mould. ·        Fibre glass reinforcement which is normally in the form of a cloth or mat is manually placed in the mould. ·        After pouring the plastic resin which are mixed with the catalysts and accelerators. ·        Rollers are used to remove entrapped air. ·        To increase the thickness of the composite being produced, more layers of  fiber  glass mat and resin are added.

DEFINITION Robot programming is defining of desired motions so that the robot may perform them without human intervention. Types of programming method for robot 1. Manual method 2. Walk through method (manual lead through) 3. Lead through method (on-line) 4. Off-line programming 1.                         Manual method :- ·        In this type of method we used for small robots and for simple applications. ·        It is more like setting up a machine rather than programming ·        By using limit switches, mechanical stops, cams, relays for control the robot motions. ·        This method mainly used for lower technology robots for short work cycles Ex – pick and place robots 2. Walk through  method  :- ·        This type of method programmer manually moves the arms of the robot through a motion sequence . ·        Each movement will be recorded in the memory for subsequent play back during production. ·        This type of

DEFINITION ·        Group technology is a manufacturing philosophy in which we are grouped the part based on the similarities in design or manufacturing process. ·        The main purpose of group technology is to reduce the overall manufacturing cost. There are two types of part families :- a)    Based on the design characteristics b)   Based on the manufacturing  characteristics 1.   Based on the design characteristics As a name suggest that the grouping of the part is based on the design characteristics such as geometric shape and size. Such part may have different manufacturing characteristics due to change in quantity, tolerance, type of material. For example:- 2. Based on the manufacturing characteristics Here part is grouped, based on the manufacturing characteristics but having different design characteristics.   For example:- Above some figure is given, in this all the part first turning operation is done Hen

Introduction Robotic sensing is the sub area of robotic science in which we are study of robotic sensor. By use of certain mechanisms the robot is interact of the environment is known as sensors. Robot sensor performs travel function like identification of object, guiding the robot without obstructions identification of path, and so on. Generally it is two types -: 1.     Internal sensors 2.     External sensors 1.     Internal sensors are used to provide information like joints position, velocity, acceleration etc... 2.     External sensor provides the information about the external environment surrounding the robot.

INTRODUCTION   Numerical control is a system which the actions are controlled by direct insertion of numerical data at some point.  NC (Numerical control) can be defined as a form of programmable automation in which the machine or machine tool action is controlled by a program. Program is containing coded numeric data .  Basic Components of NC (Numerical control) System   1. Program of instructions 2. Machine control unit or controller unit (MCU) 3. Machine tool.   Program of instructions :- ·       It is a detailed step by step Set of directions to the machine tool for doing particular work.                                                     OR ·       It is detailed step by step set of directions which tell the machine tool what to be done and in what sequence. ·       The part programme is written in coded form. ·       The part programme is fed to the machine control unit through some input media. Such as 1. Punched card 2. Magnetic

INTRODUCTION ·       This type of mechanism is used in producing intermittent rotary motion from an oscillating or reciprocating motion member. ·       The ratchet and pawl mechanism consists of a ratchet wheel and a pawl, as shown in figure. ·       The ratchet consists of a round gear or linear rack with teeth. ·       A pawl is a spring loaded member that engages the teeth of the ratchet the teeth of ratchet is uniform.  Theory of operation A ratchet consists of a round  gear   or linear  rack  with teeth. A pawl is a  spring-loaded member that engages the teeth of the ratchet. The teeth are uniform, with each tooth having a moderate slope on one edge and a much steeper slope on the other edge. When the teeth are moving in the unrestricted (i.e., forward) direction , the pawl easily slides up and over the gently sloped edges of the teeth, with a spring forcing on  it  into the depression between the teeth as it passes the tip of each tooth. When the t

END EFFECTORS(ROBOTICS) An end effectors are usually attached to the robot's wrist. It enables the robot to  perform a specific   task there are two different categories of end effectors as follows: 1.                     Grippers -- - The function of a gripper is mainly to translate some of power into grasping action of the fingers.the power input is either supplied by pneumatic, hydraulic, or electric power. ·     Mechanical grippers ·     Vacuum grippers ·     Magnetized devices 2.                    Tools as end effectors ·      Spot welding tool ·     Arc welding tool ·     Drilling  operation ·     Grinding ·     Water jet cutting tools ·     Heating torches

Introduction Boiling is the rapid vaporization of a liquid, which occurs when a  liquid is heated to its boiling point. (boiling point of water =  100 °C) Pool boiling If heat is added to a liquid from a submerged solid surface, the boiling process is referred to as pool boiling. In this process the vapour produced may from bubbles, which grow and subsequently detach themselves from the surface, rising to the free surface due to buoyancy effects.                              OR Pool boiling is a mode of boiling where the fluid is stationary in the beginning with respect to the heating surface. STAGE OF BOILING(pool boiling) Free convection boiling Nucleate boiling Transition boiling  Film boiling POOL BOILING CURVE Curve OA represents free convention boiling When we light the burner, the heat transfer takes place between the vessel and water due to free or natural convention. Thus the values of heat flux and delt