Content. • Introduction. • HISTORY. • USES. • Operations of Lathe Machine. • Parts of the Lathe. • Lathe Bed. • Headstock. • Quick-Change Gearbox. • Carriage . Introduction. Lathes The lathe is a machine tool used principally for shaping . the production lathe, the automatic lathe, the automatic screw machine, the. Introduction The principal part of a lathe are labeled below figures. . lathe is a dual head machine where the work remains fixed and the heads move towards.
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PDF | Basics of Mechanical Enginnering- Notes - Introduction to machine and power hacksaws lathe machine, Planer lathe machine, Sloter lathe machine etc. Introduction to Basic Manufacturing Processes and Workshop Technology rigid1y held in the chuck or in between centers on the lathe machine and then. Lathe is a machine, which removes the metal from a piece of work to the required Lathe machine is also known as “the mother/father of the entire tool family”.
So we will start from the beginning of the lathe machine operations. All the lathe machine operations are carried out by single point cutting tools. Facing: The process of making a flat surface on a lathe machine is called facing. The job is held on a faceplate or chuck and the tool is fed at right angles to the bed to obtain flat surfaces. To safely perform a facing operation at the end of the workpiece must be as close as possible to the jaws of the chuck. Turning: Tuning is the operation when metal removal takes place from the surface of the cylindrical workpiece. In this process, a tool is fed along the axis of the spindle.
Measuring the Diameter Most of time, a turning operation is used to reduce the workpiece to a specified diameter. It is important to recognize that, in a turning operation, each cutting pass removes twice the amount of metal indicated by the cross slide feed divisions.
This is because you are reducing the radius of the workpiece by the indicated amount, which reduces the diameter by twice that amount. Therefore, when advancing the cross slide by. The diameter of the workpiece is determined by a caliper or micrometer.
Micrometers are more accurate, but less versatile. You will need a machinist's caliper capable of measuring down to.
Vernier calipers do not have a dial and require you to interpolate on an engraved scale. I prefer a dial caliper which gives a direct easy-to-read and hard-to- misinterpret measurement. It should be self-evident that you should never attempt to measure the work while it is in motion. With the lathe stopped, bring the dial caliper up to the end and use the roller knob to close the caliper jaws down on the workpiece. I try to use the tips of the caliper since they are thinner.
Gripping the work in the thicker portion of the caliper jaws can force the jaws apart a few thou if you twist the caliper even a small amount. I like to take an initial reading of the dial while it is still gripping the work since it is easy to inadvertently twist the caliper when removing it, thus changing the reading.
You can use the locking screw on the caliper to help prevent this. Slide the jaws straight off the workpiece being careful not to twist the caliper. In other words, there is a 90 degree face moving from one diameter to the other as you can see in the next photograph. Advance the cross slide about.
To get a nice square edge we must switch to a tool with a sharp point ground to an angle of less than 90 degrees so that it can work right down into the corner of the shoulder.
Now we will use this pointed tool to make a square finishing cut into the corner of the shoulder.
Since this is such a short distance, we will use hand feed, not power feed. You can use hand feed with the leadscrew turning - just don't engage the half-nut or feed lever. This works best if you have the carriage locked on your lathe. Lock the carriage and clean up the face of the shoulder until it is square.
If you use the sharp pointed tool you will need to use fairly high RPM, say , and advance the tool slowly or you will get little grooves from the pointed tip instead of a nice smooth finish.
If you haven't made yourself a carriage lock you will need to use the half- nut to lock the carriage in place for the facing cut. Of course you must first disengage the lead screw before you do this!
Finally, you may want to use a file as described in the facing section to make a nice beveled edge on outside edge of the shoulder and on the end of the workpiece. Thread Cutting: A thread is a helically shaped groove formed on the cylindrical surface of a workpiece.
Thread cutting is an operation performed on a lathe to produce threads by using a tool whose shape will be the same as that of the thread. Types of screw threads, Screw thread nomenclature, Lathe setting for thread cutting, Types of gear trains Simple gear train Compound gear train. Drilling : Drilling is the process of making holes in the workpiece with the help of drill tools.
The drill is held on the tailstock and the drilling operation is carried out by advancing the drill in the workpiece by rotating the handle of the tailstock.
On a lathe, Drilling is generally done in the center of the workpiece. Reaming: The process of enlarging the hole in the workpiece is called reaming. Boring: The process of removal of stock from a hole in the workpiece is called boring.
Holes are bored by the single point tool. The main parts of carriage are: a. The saddle is an H-shaped casting mounted on the top of lathe ways. It provides support to cross-slide, compound rest and tool post.
The cross slide is mounted on the top of saddle, and it provides a mounted or automatic cross movement for the cutting tool. The compound rest is fitted on the top of cross slide and is used to support the tool post and the cutting tool.
The tool post is mounted on the compound rest, and it rigidly clamps the cutting tool or tool holder at the proper height relative to the work centre line. The apron is fastened to the saddle and it houses the gears, clutches and levers required to move the carriage or cross slide. The engagement of split nut lever and the automatic feed lever at the same time is prevented she carriage along the lathe bed.