Lathe machines are one of the oldest machines for processing details that are made by humans. Their construction and their method of work have led to the existence of a large part of the machines that we use today in machine production and metalworking.
Lathing is one of the most popular and preferred methods for processing different types of materials.
How do lathe machines work?
These machines work on the principle of rotation. In other words, when these machines work the details that are being processed are rotated so that we can complete different operations such as cutting, material removal, punching, indentation, etc.
The main role of lathe machines is to remove material from the detail that is being processed in order to give it a certain shape. Milling machines work in the same way but the main difference between them and lathe machines is that lathe machines work by rotating the material that is being processed and feeding it to the detail processing tool.
Some of the main types of lathe machines:
High-speed lathes
These lathe machines have a simple design which makes them easy to use in all types of conditions. Unfortunately, due to their simple design, they aren’t very popular nowadays. Why? Because their cutting tool is controlled manually, which makes them less precise in detail production.
Besides, the high-speed lathe machines achieve (up to 6000 revolutions per minute) which makes them unsafe to work with, especially if they are operated by an unqualified operator.
Some of the main operations that can be completed with these lathe machines are lathing wooden details, polishing, and metal adjustment.
Standard lathes
Some metal details require better precision during their processing and the best option for them is the use of lathe machines. We can perform different operations with these lathe machines- punching, lathing, screw threading, conical twisting, etc.
Standard lathes are equipped with a transmitting box that is attached to their head and it offers a wide speed range (from very slow to very fast).
Multifunctional lathes
Multifunctional lathes can perform different and multiple operations at the same time. Some multifunctional lathe models help us process with just one clamp different surfaces that require radial and axial processing. Others, on the other hand, allow us to process details with more than 100 tools.
The lathing process doesn’t require a highly qualified operator because the lathe machines are semi-automated or automated.
Lathes with a CNC control
The lathing process has changed drastically since CNC control entered the world of metal processing machines.
CNC lathe machines allow us to process details from different materials without any interference from an operator. We just need to program the way of work of the tools and send them to the CNC machine that starts processing the material in a fully automated way.
What is the process of lathing?
We have shown you just a small part of the different types of lathe machines but let’s check what exactly is the lathing process.
Before diving into the main steps of the lathing process let’s recap … The lathe machine uses a machine tool that processes details by holding them between two strong and hard supports that are called cartridges chambers, centers, or rotating front plates.
The cutting tool stays still at the lathe machine stand. The detail processing operations are realized by feeding the billet we need to process to the processing tool. This tool can perform operations in a parallel line or at a right angle depending on the axis of the detail that is being processed.
Main steps of the lathing process
1. Checking the condition of the lathe machine before starting to operate with it
This first step is very important as the operator needs to know well whether the machine is in good working condition. The operator checks if all elements of the machine are where they should be, whether the mechanisms are closed, whether the control arms of the mandrel and the power supply are in a neutral position, whether the cooling liquid flow is turned off and whether the fluid nozzles are in a downward direction.
- Mandrel control
Before starting the mandrel is highly recommended for the operator to check if there is a risk for the rotating elements (and more specifically) to be blocked by the unmoving parts of the machine.
- Settings
Depending on the detail that needs lathing we need to make certain settings for the tools.
4.Lathing
If the lathe machine has manual control. This requires feeding the detail we need to process to the cutting tool/tools, as well as changing the tools if the processing of the detail requires it.
If the lathe machine is multifunctional it allows us to install many tools in its structure which will process details in a certain order. The operator of such a lathe machine is required to install additional tools on the lathe machine. After this the process of detail lathing is automated.
Lathe machines with a CNC control don’t require an operator with much experience because the lathing process is fully automated. These lathe machines can not only perform different detail processing operations, but they also reduce processing times, increase efficiency and reduce to a minimum the production of imperfect items.
Lathing with a CNC machine requires us to enter into its memory a previously developed CAD program. This previously programmed software is responsible for all subsequent processes- from changing the tools and detail processing to getting the final result.
Advantages and disadvantages of conventional lathe machines and machines with CNC control
Conventional lathes
There are several main advantages of lathe machines without a computer control:
- the considerably low buying price - here we need to make it more clear and say that this low buying price depends on different factors. These are the model of the lathe machine and the operations it can perform. There are lathe machine models that are designed for home workshops and their price is really low but there are also multifunctional semi-automated or automatic lathe machines that are offered at high prices.
Disadvantages:
- require the presence of an operator who not only needs to watch the lathing process but also interfere with the process and help when it’s needed.
- low efficiency- regardless of the abilities and the qualification of the lathe machine’s operator, conventional lathe machines don’t have the capacity to process a large number of details for a short period of time.
- lack of precision - if the lathe machine operator doesn’t have enough experience in working with such machines the likelihood of processing details without precision is high. And this also means that these machines produce a large amount of scrap.
Lathe machines with CNC control
Advantages:
- high precision during the lathing process - unlike conventional lathe machines those with CNC control can process details in a very precise way. Besides, all details that are lathed with a CNC lathe machine have the same precise measurements.
- they can work in an uninterrupted work mode - because they are fully automated these lathe machines can work in a three-level work mode which increases many times the number of details that can be processed for 24 hours.
- they can be controlled by an underqualified operator - because the machine is automated it doesn’t require an operator with rich experience
- operators can make changes at every moment if needed
- lathe machines with CNC control can process details with a complex designin a very precise way.
Disadvantages:
Although CNC lathe machines have a lot of advantages they also have several disadvantages:
- high price - the price of such a machine is considerably higher than any conventional lathe machine.
- expensive parts;
- high maintenance expenses.
Past, present, and future of lathing
In the beginning of this article, we have mentioned that the lathing process has been known for a very long time. To be completely exact we need to mention that such types of machines were used in ancient Egypt.
Of course, they didn’t look exactly like the modern machines we know today. However, there is no doubt that humanity many years ago realized the advantages of lathe machines and used them.
Lathe machines were used in ancient Greece, Assyria and ancient Rome. The Romans improved the design of the lathe machines that were developed by the Egyptians by adding a manual driving mechanism which made the machines easier to control.
In the Middle Ages manual driving is replaced with a pedal which leads to hands-free control. Thanks to this pedal the operator could process details in an easy way as they were able to hold the tools with their free hands. Lathe machines with such a mechanism were used until the beginning of the 20th century.
One of the first lathe machines that were used in Europe was a horizontal punching machine that was created in 1772 in the United Kingdom by Jan Verbruggen. One of the key characteristics of this machine was that during the processing the detail was performing the rotation instead of the processing tool. This was in fact the first lathe machine that utilized the same detail processing technique that we know today.
Since the end of the 19th and the beginning of the 20th century, lathe machines have experienced many considerable changes. One of them is related to the shafts that are replaced with electromotors as a power source. Another change is the addition of several processing tools that process one and the same detail in several consecutive steps, etc.
In the 50s, a servo controller was introduced into the control mechanism of lathe machines. This marks the beginning of lathing with CNC machines.
Today conventional lathes and CNC lathe machines are both used in different production processes, but the future belongs to CNC lathe machines.
