Featured post

Types of mechanical forces

-
A force exerted on a body can cause a change in either the shape or the motion of the body.The unit of force in SI system is the Newton(N) and CGS system is dyne.No solid body is perfectly rigid and when force are applied to it,changes in dimension occur.such changes are not always perceptible to the human eye since they are negligible. For the example,The span of a bridge will sag under the weight of a vehicle and a spanner will bend slightly when tightening a nut. It is also important for civil engineers and designers to appreciate the effects of forces on materials.Together with their mechanical properties of the materials. There three main types of mechanical forces that can act on a body.They are 1)Tensile force 2) compressive force and 3) shear force
2 comments

Machining processes

-
New Guinea in 1943. Mobile machine shop truck of the US Army with machinists working on automotive parts
Machining is any of various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process. The processes that have this common theme, controlled material removal, are today collectively known as subtractive manufacturing,[1] in distinction from processes of controlled material addition, which are known as additive manufacturing. Exactly what the "controlled" part of the definition implies can vary, but it almost always implies the use of machine tools (in addition to just power tools and hand tools).
Machining is a part of the manufacture of many metal products, but it can also be used on materials such as wood, plastic, ceramic, and composites.[2] A person who specializes in machining is called a machinist. A room, building, or company where machining is done is called a machine shop. Machining can be a business, a hobby, or both. Much of modern-day machining is carried out by computer numerical control (CNC), in which computers are used to control the movement and operation of the mills, lathes, and other cutting machines.

Comments

Post a Comment

Popular posts from this blog

Tailstock

-
Image
The tailstock is located on right side of the bed i.e.right hand side of the operator. The main purpose of a tailstock on an engine lathe is to support free end of a work during operation.it is also used to hold tools for making holes (twist drills,reamers) adjusted along the bed of the lathe accommodate different lengths of stock.it is provided with set over screw at its base for taper turning alignment.it has cast iron body with bore to accommodate tailstock spindle,and the top portion contains the spindle,tailstock hand wheel, and a spindle clamp for locking the spindle in position. The end of the spindle has a taper bore for holding dead centre,taper shank drills and other tools.the spindle can centre,taper shank drills and other tools.The spindle can be moved in and out of the tailstock by the rotation of hand wheel in anticlockwise and clock wise direction respectively.A tailstock is shown in fig.
Read more

ADVANTAGES AND LIMITATIONS OF BROACHING:

-
Broaching is an interesting machining process which is used in mass production. It has certain advantages and limitations as compared to the other machining processes.these are given below. ADVANTAGES : 1) Fast and simple process. 2)High degree of accuracy and finish is possible. 3)Any shape of profile can be easily machined. 4) Machining process is completed with one stroke of broach. 5) Life of broach tool is high. 6)Cutting temperature and tool wear is low. 7) Doesn't require a highly skilled operator. 8)Cutting force acts in the clamping direction I.e.,it doesn't tends to lift the workpiece from fixture. 9)cutting fluids can be applied more easily and effectively. 10)Most economical for mass production of components. LIMITATIONS: 1) Not economical for small quantity productions. 2)Cost of broach is high. 3) Tool grinding (broach sharpening) is difficult and expensive. 4) Not suitable to machine a surface having obstruction. 5) The work m
Read more

METHODS OF APPLICATIONS OF CUTTING FLUIDS :

-
Image
The method of application of a cutting fluid is very important and depends on the particular operation. These methods vary from hand applications such as use of brush or oil-can to high pressure applications.For high production. The following methods are used.    1)Flood method,    2) Jet method,and    3) Mist method. 1) Flood method : In this method,a reciprocating pump is used to force the coolant over the work and tool.The outlet of the pump is connected to a nozzle through flexible pipe.The nozzle can be adjusted to direct the stream of the fluid at the cutting zone.This is the most common method of application of cutting fluid. 2) jet method : In jet method,a small jet of fluid at high speed is directed at the point of metal separation from the underneath the tool.In high-speed jet system gear or vane type pump is used to maintain high pressure. 3) Mist method : In mist method,the fluid is passed through a specially designed nozzle to form very fine drop
Read more