Lathe Machine Workshop Report

Title

Introduction to Lathe Machine

Objective

To familiarize the operations of lathe machine

Apparatus/Material

·        Lathe machine

·        Digital Vernier Caliper

·        Goggles

·        Steel bar for the use

Introduction

                        Lathe machine is a very useful machine in metal industry. Lathe machine obtained a rotating work piece and stable cutting tool. Lathe machine have many uses in industrial area like cutting, drilling, sharpening, cutting threads etc. We must use few protection methods when we work with the lathe machine such as goggles. Lathe machine introduction was so interesting and important to our future work.

Procedure

·        First of all, we identified the main parts of the lathe machine with the help of instructors.

·        After that some we were ordered to wear goggles, tie up loose hair and bend up the long sleeves by instructors.

·        Then an idea about the on/off button and emergency button was had by us.

·        And the speed was set to stage B-2 by the instructor.

·        After all these pre-preparation steps were taken, the cross-slide hand wheel was turned clockwise till the cutting tool touches the workpiece by us.

·        And then scale on the cross slide handwheel has taken to the zero point without touching the handwheel.

·        As soon as it turns to zero, carriage was moved out from the workpiece using the hand wheel till the corner of the metal.

·        After placing the cutting tool at the corner of the metal bar we pulled down the half nut leaver to make it still and then we turned the cross slide handwheel till the scale shows 1mm reduction of the diameter.

·        And also, we marked the length we need to make the thread.

·        After all these steps are correctly done, we turned on the lathe machine using the red color leaver and pull up the half nut leaver to make it move automatically.

·        Finally, the machine was turned off by a student when it came to the point we marked before.

·        Same procedure was done again and again till the diameter value measured by the digital Vernier caliper shows 20.2mm.

Discussion

Types of Lathe Machines

1.     Speed Lathes

These lathes in two types as bench type and supporting legs lathe machine. These lathe machines don’t have gear box, carriage and the lead screw. Mainly use wood turning, polishing, centering and metal spinning, etc.

2.     Engine Lathes

These lathe machines are the most common type of lathe machines. These machines are designed for low and high-power operations. In this lathe machine various types of metals can be lathe. This machine has different type of speed ratios. It can be used for lathe a work piece of 60 ft.

3.     Tool room Lathes

It is a very versatile lathe machine. It can give better accuracy and finishing. It has wider range of speeds. It can give different types of feeds. It can be a great device to manufacture die.

4.     Turret Lathes

These types of lathes are used for machining single work piece, which means sometimes there are several modifications should be done to the same work piece; we can do that using this lathe machine. For that it has attached few types of tools to that purpose. It eliminates the errors that happen due to misalignments.

5.     Special Types of Lathe Machines

These are the machines which are allows the worker to perform tasks which are not possible in normal lathe machines. These lathes include –

·        bench type jeweler’s lathe

·        Automatic lathes

·        brake drum lathes

·        multipaneled lathes

·        crankshaft lathes

·        duplicating lathes

Operations which can be performed using a lathe machine

1. Straight turning                                      13. Spring winding

2. Shoulder turning                                   14. Undercutting

3. Taper turning                                          15. Spinning

4. Chamfering                                             16. Parting-off

5. Eccentric turning                                   17. Internal thread cutting

6. Thread cutting                                        18. Drilling

7. Facing                                                       19. Reaming

8. Forming                                                    20. Tapping 

9. Filing

10. Polishing

11. Grooving

12. Knurling

Different types of work holding devices used to hold a work piece in a lathe machine

Chuck

          There are different types of chucks namely, Three jaw universal chuck, Four jaw independent chuck, Magnetic chuck, Collet chuck and Combination chuck.

1.     Three jaw universal chuck

The three jaws fitted in the three slots may be made to slide at the same time by an equal amount by rotating any one of the three pinions by a chuck key. This type of chuck is suitable for holding and rotating regular shaped workpieces like round or hexagonal rods about the axis of the lathe. Workpieces of irregular shapes cannot be held by this chuck.

2.     Four jaw independent chuck

There are four jaws in this chuck. Each jaw is moved independently by rotating a screw with the help of a chuck key. A particular jaw may be moved according to the shape of the work. Hence this type of chuck can hold woks of irregular shapes. But it requires more time to set the work aligned with the lathe axis. 

3.     Collet Chuck

Collet chuck has a cylindrical bushing known as collet. It is made of spring steel and has slots cut lengthwise on its circumference. So, it holds the work with more grip. Collet chucks are used in capstan lathes and automatic lathes for holding bar stock in pro- duction work.

4.     Magnetic Chuck

The holding power of this chuck is obtained by the magnetic flux radiating from the electromagnet placed inside the chuck. Magnets are adjusted inside the chuck to hold or release the work.

Driving Plate

It is used to drive work piece when it is keep between centers. Driving plate is a round disc which tighten to the nose of the lathe spindle. In this working tool it has small bolts or pins on its face. The work piece is fit inside straight tail carriers are held and rotated by driving plates.

Face Plate

                   This working tool is using to hold large, heavy and irregular shaped work pieces which cannot be held using normal chucks. This working tool is a circular shaped disc which bored out the threads to fit to the nose of the lathe spindle.

Meaning of CNC Lathe Machine

CNC lathe machines are well known as high production and lower costs lathe machine. CNC lathe machines are highly used for manufacturing high quality components or parts as it operates with the help of a computer program. It is use in many fields like electrical, electronic and automobile etc. This lathe machine is use for large scale productions.

Possible Errors

            There were few errors that could occur when taking measurements and using the lathe machine. As an example, when we take measurements we’d have to take multiple measurements to reduce the error. But for our easier we only

took one measurement, so there would have been happen an error.

Another error is that we put a mark where we need to stop the machine, but unfortunately the mark was passed because of our careless work.

Possible Hazards and protection

            There were lots of possible hazards that can happen when using lathe machine. Caught hand/clothes/hair to the lathe machine and hitting metal pieces in eyes are some of them. For our own security we learned about the lathe machine before use and wore goggles also we didn’t reach the machine when it’s on. Luckily, we didn’t face any of these hazards during the workshop because our instructors’ advices.

Conclusion

            Overall, we had a good idea about how to work with the lathe machine at slit workshop. And also, about other kinds of lathe machines and all the parts of lathe machine. Information we gathered from this workshop session will be very useful to our lives in our future path of being an engineer.

References

Profile, A. (2018). Types of Lathe Machines. [online] Mechanical Engineering. Available at: https://basicmechanicalengineering.com/types-of-lathe-machines/ [Accessed 4 Aug. 2018].

Learn Mechanical Engg. (2018). 25 Basic Operations Performed On Lathe Machine. [online] Available at: http://learnmech.com/25-basic-operations-performed-on-lathe/ [Accessed 4 Aug. 2018].

Educationdiscussion.com. (2018). Work Holding Devices Used in Lathe Machine | Education Discussion. [online] Available at: http://www.educationdiscussion.com/work-holding-devices-used-in-lathe-machine/ [Accessed 4 Aug. 2018].

Google.lk. (2018). cnc lathe machine - Google Search. [online] Available at: https://www.google.lk/search?rlz=1C1CHWL_enLK806LK806&biw=1536&bih=728&ei=-RtmW-LeGpK-9QOO4rHoBQ&q=cnc+lathe+machine&oq=cnc&gs_l=psy-ab.3.1.0i67k1l7j0i131k1j0l2.1419.1733.0.4029.3.3.0.0.0.0.193.372.0j2.2.0....0...1.1.64.psy-ab..1.2.371...35i39k1.0.fFJdfhDHOeI [Accessed 4 Aug. 2018].

Americanmachinetools.com. (2018). How To Use a Lathe. [online] Available at: http://www.americanmachinetools.com/how_to_use_a_lathe.htm [Accessed 4 Aug. 2018].

Profile, A. (2018). Types of Lathe Machines. [online] Mechanical Engineering. Available at: https://basicmechanicalengineering.com/types-of-lathe-machines/ [Accessed 4 Aug. 2018].