 students. This is Mr. Nagesh Artambaki, Assistant Professor, Department of Mechanical Engineering, Valshan Institute of Technology, Sholapur. Today, we are going to discuss on the topic attachments of leg machine, learning outcome. At the end of this session, students will be able to explain attachments of leg machine. Before going to discuss the attachments of leg machine, what type of operations cannot be performed on leg without attachments that we are going to think. Please think on this particular question. The operations that are that cannot be performed on the leg machine without attachments are grinding, milling, copying and then relieving. This type of operation cannot be performed without attachments. Now content in this particular session we are going to discuss. Introduction of leg attachments, grinding attachment, milling attachment, taper turning attachment, copying attachment and relieving attachment. Each general purpose conventional machine tool is a designer and used for a set of specific machining work on jobs of limited range of shape and size. But often some unusual work also need to be done in a specific machine tools. Example, milling in a lathe, tapping in a drilling machine, gear teeth cutting in a shaping machine and so on. Under such conditions, some special devices or systems are additionally used being mounted in the ordinary machine tools. Now first one we will discuss that is the grinding attachment. This grinding attachment is placed instead of tool post of a lathe also known as the tool post grinder. It is mounted on the compound rest as a substitute for the tool post. It consists of a base plate, grinding wheel and a motor. The workpiece is held in a chuck or between centers. It is widely used for grinding lathe centers in position. Grinding operations can be performed on the lathe with this attachment. This useful attachment can be mounted on any lathe. Grinding hardened workpieces and ensuring a smooth finish. Internal grinding can be carried out with this grinder. Milling attachment, we can able to perform a milling operation on the lathe machine with this particular attachment. This is a milling head comprising a motor, a small gearbox and a spindle to hold the milling cutter mounted on the saddle after removing the cross slide etc as shown in the figure. Milling attachment are generally used for making flat surfaces straight and helical grooves flanks, long and deep screw threads, worms etc. In centerless by using suitable milling attachment, taper turning attachment, five types of taper turnings are there. One is with the help of form tool method. Second one is by combination field and third one is by tailstock set or method and fourth one is the taper turning attachment. And also fifth one is this prevailing compound rest method but we are going to discuss this attachment. The function of a taper attachment is to guide the tool in a direct path set at an angle to the axis of rotation of the workpiece. A taper turning attachment consists of a bracket or frame that is attached to the end of the lathe bed supporting a guide bar, pivoted at the center the bar with graduations and degree can be swelled on either side of the zero graduation. It can be a set of desired angles, desired angles can be given on the lathe. And this particular taper turning with the help of this particular taper turning attachment we can give a taper angle for a long jobs that is the advantage of this particular taper turning attachment. And also we are going to discuss benefits of the taper turning attachment. It leaves the alignment of dead and live centers untouched. So both straight and taper turning may be performed in one setting without a downtime. Once the taper is set any length of a piece of work could be turned within limits. Several work pieces could be turned. Internal tapers can be turned effortlessly. Now next one is mechanical copying attachment. Suppose we have performed a one masterpiece and if you made a guide of that definitely that particular guide will help us to give the multiple jobs with a copying attachment. A simple mechanical type copy turning attachment has been schematically shown in the figure. The entire attachment is mounted on the saddle after removing the cross slide from that. The template replicating the job profile desired is clamped at a suitable position on the bed. The stylus is fitted in the spring loaded tool slide and while traveling longitudinally along the saddle moves in transfer direction. According to the template profile enabling the cutting tool produce the same profile on the job as indicated in the figure. Next one is hydraulic copying attachment. The stylus moves along the template profile to replicate it on the job. Now if we compare with the mechanical copying attachment mechanical copying attachment produces a vibration and noise because of that we cannot get a finished object after a mechanical copying attachment many times. Therefore in hydraulic copying attachment hydraulic copying attachment is costlier than the mechanical type but works much smoothly and accurately. As compared to the mechanical the hydraulic copying attachment is accurate. The cutting tool is rigidly fixed on the cross slide which also acts as a wall come cylinder as shown in this figure. So long the stylus remains on a straight edge parallel to the lathe bed the cylinder does not move transversely and tool causes straight turning. In cross fit direction the ports open and the cylinder starts moving accordingly against the piston fixed on the saddle. The slide holding the tool by same amount traveled by the stylus encloses the ports. Last one is the reliving attachment. This attachment we are using to produce the gears to produce the slots on a circular objects. The teeth of form relived milling cutters like gear milling cutters, tabs, halves etc are provided with flank having archimedes spiral curvature machining and grinding of such curved flanks of the teeth reliving motion to the tool or wheel as indicated in figure. The attachment schematically shown in figure is comprised of spring loaded bracket which holds the cutting tool and is radially reciprocated and the saddle by a plate cam driven by the fluid rod is indicated. So due to continuous reciprocating action it will give us gears and different slots on the circular object, equidistant slot on a circular object. Now these are the references Hajra Choudhary, elements of workshop technology volume 2 media promoters, PM Rao, manufacturing technology, battle cutting and machine tools. In this particular session we were discussed the different attachments on the lathe and these attachments that we require when that we require for the smaller objects. If we do not have the milling machine then grinding machine then such type of machines then definitely with the help of these attachments we can perform the allied operations and we can perform a job of required ships. Thank you.