Lathe 101: Working, Types & Uses

Lathe Machine
The lathe is the simplest of all the metalworking machines. Have you ever wondered how those symmetrically looking shiny components inside your Scooter, Motorbike, and Food Processor are manufactured? 
Let us explore together the world of ‘LATHE MACHINES’ which is known as the Mother Machine.

What is a Lathe Machine?

The principle of your Lathe Machine is to turn or rotate the work-piece on a horizontal axis and cut the material with a cutting tool to generate an external surface called Outside diameter (OD) and an internal surface called an inside-diameter (ID) or bore. Your work-pieces can be a bar stock, forging, or casting. You can select different cutting speeds and feeds for turning different materials. Your Lathe Machine is also known as an Engine Lathe since it was driven by a steam engine in its initial days.

Lathe Diagram – How it Works?

The following diagram explains the basic working principle of the machine.

Lathe Diagram - Working Principle

Major specifications of your lathe are, the maximum distance between the live and dead center and the height of the center over the guideways and carriage. The first one indicates the maximum length of work which you can turn and the second one (A and B in the sketch) indicates the maximum diameter which you can swing/ revolve safely over the guideways and carriage.

Great!  Now it is time for us to continue our exploration and gain some knowledge about the different types of Lathe Machines and their utility, pros and cons.

12 Types of Lathe Machines and Their Uses

Here is the list of 12 common types of lathes that are most widely used in wood and metal working industries.

1. Wood Turning Lathe. 9. Vertical Turret Lathes.
2. Speed Lathe. 10. Special Purpose Lathes.

  1. Jeweler’s Lathe.
  2. Crankshaft Turning Lathe.
  3. Wheel Lathe
  4. Copy Lathe
3. Centre Lathe or Engine Lathe.
4. Gap Bed Lathe
5. Tool Room Lathe.
6. Bench Lathe.
7. Hollow Spindle Lathe. 11. Automatic Lathes.
8. Turret and Capstan Lathes. 12. CNC Lathes.
Now, let’s see each of these machines in detail and the uses of these lathes. Are you ready!

1. Wood Turning Lathe

Remember the rolling pin in your mother’s kitchen or round legs of your sofa and colorful wooden toys! Well, you can do all these and more on a Wood Turning Lathe.

Your Wood Turning Lathe comes with a headstock with motor and a drive system, spindle with chuck, tool rest to support handheld tools, and tailstock, all mounted on a bed or base. Both tabletop and base mounted machines are available for you.

You will have 5 to 6 simple tools for doing the turning, facing, boring, parting, grooving, and beading. Your tool material can be carbon steel, High-Speed Steel (HSS) or carbide.

You should develop good skills to use these hand tools. Sandpaper is used on the rotating work-piece to improve surface finish.

You can use Wood Turning Lathe in foundry pattern shop, house hold items, toys and to implement creative ideas in your mind.

Pros:
Your Wood Turning Lathe is productive.
Cons:
Your investment can be idle if you cannot use it profitably.

2. Speed Lathe

Your Speed Lathe has the same features as Wood Turning Lathe, but it is sturdier, has 2 or 3 spindle speeds from 1200 to 3600 rpm and tool post mounted on the adjustable slide to give feeds manually. Your depth of cut will be small resulting in good finish. You can turn wood or metal components and do spinning.

Pros:
You will be able to do fast and good quality jobs on your Speed Lathe.
Cons:
Lack of planning and skill to use this machine may put you back in business.

3. Centre Lathe or Engine Lathe

Your Centre Lathe has all the parts described above and you can turn outside-diameter, bore, facing, centering, taper turning, threading, knurling etc. You can mount drills, taps, and reamers on the tailstock and do drilling, reaming, and tapping. The rigid construction and spindle speeds allow you to give heavy cuts.

You can use attachments like tool post grinder, copying, and milling; and study rest and tailstock for supporting lengthy jobs.

Pros:
Your Centre Lathe is a very versatile machine.
Cons:
Your Centre Lathe is slow and not suitable for mass production.

4. Gap Bed Lathes

Your Gap Bed Lathe has all the features of a Centre Lathe except that there is a gap on the bed near the Headstock to turn a higher diameter. You can close the gap with the given insert.

Pros:
Your Gap Bed Lathe helps you to do higher diameter components and regular components.
Cons:
The cost of your Gap Bed Lathe is more than Centre Lathe, be sure before investing.

5. Tool Room Lathe

Construction-wise your Tool Room Lathe resembles a Centre Lathe. However, when you start using it you will understand that the Tool Room Lathe is built with higher precision and increased range of speeds, gear ratios, and feeds for smooth operation and to cut threads in inch, metric and other systems. You use your Tool Room Lathe, installed under a controlled ambiance, for producing components of cutting tools, dies, gauges, jigs, fixtures, and precision parts.

Pros:
versatility and precision are the trump points of your Tool Room Lathe.
Cons:
Cost of your Tool Room Lathe is quite higher than Centre Lathe, be sure before investing.

6. Bench Lathe

Your Bench Lathe, also known as Mini or Hobby Lathe is a mini version of the Centre Lathe and has most of its standard features. It weighs approximately 150 Kgs and you can mount it on a work table or on its own base.

You can use the Bench Lathe in Automobile service Centre, village workshop, repair shops and also as a hobbyist.

Pros:
Having a Bench Lathe in your service centre helps you to meet your commitments.
Cons:
Investment can be deferred if you have a reliable out-sourcing facility.

7. Hollow Spindle Lathe

Your Hollow Spindle Lathe is a Centre Lathe, however, it has a spindle with comparatively larger bore facilitating loading of long tubular work pieces through the bore and you can turn the ends without the necessity of long beds.

Pros:
Your Hollow Spindle Lathe makes your work faster.
Cons:
Be sure of your work flow before committing additional investment.

8. Turret Lathes and Capstan Lathes

For mass and repetitive production, you choose a productive machine such as a Turret or Capstan Lathe.

In your Turret Lathe the tailstock is replaced by a hexagonal turret which holds six end working tools that can be indexed and moved on the saddle along the spindle axis. You have your standard tool post with turning tools mounted on the movable tool post slide of the carriage. You use the feed rod to move the carriage or turret under power. The construction is robust, allows you to use heavy cuts and the chuck has power jaws.

You can do turning with the tool post tool and simultaneously do drilling using the drill on the turret head. The Turret Lathe is tooled up and maybe semi-automated and you need not be highly skilled to operate it.

The tool on the turret is indexed automatically when you roll back the turret on its saddle.

Your Capstan Lathe has the features of the Turret Lathe, but there are major differences, viz. Capstan Lathe is faster due to its light construction and it is designed for turning small work-pieces held in collets. You can only give a small depth of cuts. The capstan head of your lathe is mounted on a ram fixed on the saddle and you can feed the tool by moving the ram.

Pros:
Your Turret and Capstan lathes are productive machines.
Cons:
Due to large number of components, wear and tear is more.

9. Vertical Turret Lathe (VTL)

You have to use VTLs to turn large diameters or large non-symmetrical shape components.

Your VTL has most of the features of the Turret Lathe but has a vertical orientation. You can move the turret head in two directions and do turning, boring and facing. You can clamp the work-piece on the circular table on four-jaw chuck or clamps. You can use the side tool for turning outside diameter.

Pros:
A vertical turret lathe is a versatile machine.
Cons:
Conventional VTL is slow when compared with CNC.

10. Special Purpose Lathes

You need Special Purpose Lathes for components like a tiny watch component, an asymmetrical item like a crankshaft, or a typical item like a rail carriage wheel-set.

Jeweller Lathe

The Jeweller Lathe is small enough to hold in your hand; however, for convenience, you mount it on a table. Your Jeweller Lathe has a headstock spindle with chuck or collet and driven by motor and pulley; tailstock and a tool rest for the hand tool. You must have the skill to use your hand tool to turn metallic and non-metallic workpieces. Your Jeweller Lathe is also known as Watchmaker Lathe since you can use it to turn watch spare parts.

Pros:
You can work on the machine and improve your earning.
Cons: It will add to your cost if you need to hire a person to work on the machine.

Crankshaft Turning Lathe

You observe that a crankshaft has its main journal diameters on one axis and the connecting rod journal diameters on a different axis.

You can turn the main journal diameters by loading it between chuck and tailstock.

However, for turning the connecting rod journal diameters, you will use a fixture on the lathe to bring its axis in line with spindle axis.

Pros:
If you can generate work flow this can be a good investment.
Cons:
You have to compete with units who use latest technology where multi-point cutters are used on high-tech machines.
 

Wheel Lathe

You use a Wheel Lathe for machining the forged wheel set of a rail-coach due to its typical construction. They are huge in size and allow you to mount the wheel set between the chuck and the tailstock.

Pros:
Cost of your Wheel Lathe is lower than automated Lathes and can do the same job.
Cons:
Wheel Lathe is slow and not suitable for automated mass production, where CNC is used.
 

Copying Lathes

You can use them to turn shafts with multi diameter steps and the turning will be fast and accurate since the turning profile is copied from the master to the work-piece by hydraulic mode.

Pros:
Your Copying lathe is good for mass production.
Cons:
You need to justify your higher investment.

11. Automatic Lathes

Your Automatic Lathe can be single or multi spindles and with provision for bar feed or chuck. You can do complete sequence of operations, including change of speeds and feed, tool movement, turret movement and bar feed automatically by means of a set of cams or limit switches. Simultaneous multi-tool operation is a common feature in your machine.

Your Multi Spindle Automatic is similar to a Single Spindle Automatic, but more sophisticated since more than one work-piece (normally 6 or 8) are machined simultaneously.

Pros:
Your Automatic Lathes are highly productive.
Cons:
Wear and tear is more due to more mechanical parts and tool set-up time is high.

12. CNC Lathe

Your Computer Numerical Control (CNC) Lathe is operated using CNC systems where the Lathe follows the step-by-step instructions given by the CNC system. You can feed the instructions into the CNC system either by directly using the system keyboard or design it offline on a Computer-Aided Design (CAD)/ Computer-Aided Manufacturing (CAM) system and transfer it to the CNC system. Your CNC Lathe is good to go, once you establish a trial component, and will run automatically without needing much of your attention. Your CNC Lathe will have features similar to your Centre Lathe with few exceptions.

The CNC system on your lathe has closed-loop feedback and monitors the program continuously in real-time and implements corrections to ensure repetitive mass production of components.

Your CNC Lathe can be of two or more axes and horizontal or vertical configuration.

Pros:
Your CNC Lathe is reliable for mass production of repetitive components.
Cons:
Your investment is very high and you have to be very sure before investing.

Conclusion:
Your Centre Lathe is a very versatile machine and known as the mother of all other Machine Tools. Advancement in your Centre Lathes has given birth to today’s CNC Lathes and high tech Machining Centres.  Even with all the advancements in technology, you may still need your Centre Lathe when you quickly need a single or small batch of components.