Sometimes you need to perform several different machining operations on a workpiece to complete a machining job.
If the job is more turning oriented, you must use a turning-based tooling system that allows diverse operations.
A gang tool lathe is a great choice for such jobs.
A gang tool lathe is a type of CNC lathe that employs a unique tooling system having multiple tools placed in a parallel fashion on its cross slide, allowing it to perform different operations in a sequence. It helps speed up machining by reducing tool change time and boosting efficiency.
This article discusses gang tool lathe by explaining its setup, parts, operations, and how it differs from a turret and live tooling.
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Gang Tool Lathe: How does it Work?
Gang tool lathes can machine parts in less time than a typical CNC lathe. This is possible because of its unique tooling setup, known as gang tooling.
It offers an optimal solution for producing small parts in large quantities that require multiple machining operations to finish the part.
Parts of a Gang Tool Lathe
The lathe bed is an important structural element of a lathe machine. It is made of hardened cast iron to provide rigid support to the lathe's moving parts.
The headstock is the stationary part of a gang tool lathe. It houses the drives of the main spindle and facilitates the bar's feeding with a bar feeder's help.
The chuck, usually a collet chuck on a gang tool lathe, holds the workpiece in a stable position and turns it allowing the machine to perform different machining operations.
Gang tool holder
Gang tool holders are unique tools that can accommodate multiple CNC lathe tools like drill bits, end mill cutters, turning tools, boring bars, etc.
You can accommodate machining cutters of different sizes using suitable holders.
Gang tool holders have holes that provide provisions to hold drill chucks, boring bars, or tool bushings with the help of tightening screws.
Few gang tool plates also offer provision to supply cutting fluids while machining.
The gang tool holder is fixed to the cross slide over the lathe bed. CNC-controlled actuators direct its movement.
Based on the part's complexity, a machine with a suitable axis system is used for manufacturing.
Most gang tool lathes have a 3-axis configuration. Its 4 or 5-axis versions are used in industrial setups to work on more complex jobs.
Operations Performed Using a Gang Tool Lathe
Gang tooling is effective when machining small repeatable parts. Also, it allows you to perform different machining operations like turning, drilling, boring, milling, grooving, etc.
The gang tool lathe repositions the cross slide to engage different tools sequentially to the workpiece.
In the turning operation, the surface material of a rotating workpiece is removed using a cutter.
There are different types of turning operations based on the cut made. This includes forming, chamfering, taper turning, contour turning, etc.
You can accommodate a gang tool holder with a drill bit to tap holes or carve shapes on the workpiece.
This type of tooling system can perform operations like face drilling and side drilling.
Boring is a machining process in which a boring bar is used to enlarge existing cylindrical or conical holes on a rotating workpiece.
The threading operation helps produce helical threads of different pitches on a workpiece.
You can set up the gang holder with different threading tools to cut threads of varying pitches.
You can use the G76 or G32 cycle to perform CNC threading on a gang tool lathe.
A gang tool holder can also accommodate an end mill cutter that helps produce contours, flats, and slots.
Gang Tooling vs Turret Tooling vs Live Tooling
Gang Tooling vs Turret Tooling
|Parameters||Gang Tool||Turret Tool|
The setup of gang tooling is simple. It has a long plate onto which you can sequentially attach many tools.
Turret tooling requires a precise indexing device on which all the tools are mounted.
You must arrange the tools carefully in both setups, as the machining cycle would be programmed according to its position.
As you can do multiple operations simultaneously, the tool post must be rigid enough to transfer excessive forces to the lathe bed. It should also effectively absorb vibrations.
Note that the machining forces can develop along multiple axes. Therefore, you should choose the jigs and fixtures carefully to avoid unnecessary movement.
Tool Changeover Time
The time required for tool changeover in gang tooling is relatively less than in a turret tooling setup. This is because gang tooling only includes the to-and-fro positioning of the tool.
Even the whole set of tools, including the gang plate, can be held as a single entity for future operation.
But in turret tooling, the whole device carrying the tools needs to be retracted from the cross slide to replace a group of tools.
Though the changeover time may only differ by a few seconds, there is a significant difference when assessing the production volume.
The overall machining time in a gang tooling setup is less than in a turret setup.
Gang tooling offers better accuracy than turret tooling.
This is due to the simplicity of its construction and the presence of fewer moving parts than gang tooling.
Hence the chances of error in dimensions while machining in gang tool lathes are far less than with the turret lathe.
Programming the tool position in the gang tool lathe is difficult for the tools that must be positioned on either side of the workpiece.
So careful dimensional analysis is needed to prevent the tool from crashing into the workpiece.
On the other hand, in turret tooling, the tools are arranged in an indexing device. Hence, it is relatively easier to program the tool positioning.
The cost involved in owning a turret tool lathe is more when compared to a gang tool lathe.
This is because of the advanced mechanism used in turret lathes to handle multiple tools around the workpiece.
Turret toolings offer more flexibility than gang tooling. For example, parts that are long or in diameters that range from slender to broader can be easily machined using turret tooling.
Gang tooling shows inadequacy in machining long slender parts or parts of huge diameters as it cannot accommodate a tailstock due to space constraints.
Gang Tooling vs Live Tooling
The workpiece must be removed from the lathe to machine a flat in a gang tooling setup.
But on a live tooling setup, you can use an end mill to work on the machined part to create a flat without swapping it between different machines.
Another great advantage of live tooling is the gear hobbing operation.
Machined gears usually have a rough surface that causes noise while operating. Therefore it should be transferred to another machine to improve its surface finish.
A live tooling setup can perform these tasks on the same machine center used to cut gears.
The live tool is a secondary attachment to the turret tooling system. So, the advantages of the turret apply to the live tool as well.
Compared to a gang tooling setup, the following parameters are enhanced by using a live tooling system.
|Structure||Complex - requires an additional motor|
|Changeover time||Fast - eliminates the need for machine change|
|Accuray||Better - because of improved finish|
|Tool Programming||Increased complexity from the multiple-axis control|
|Cost||Expensive, but the cost is recovered from reduced machine changeover time|
|Flexible||Flexible because multiple operations are done simultaneously|
Gang Tool Lathe vs Swiss Lathe
A gang tool lathe and a swiss lathe have a similar-looking setup. But they have differences in the workpiece length and live tool compatibility.
The sliding headstock and guide busing setup on a swiss lathe allows you to work with long stocks.
A gang tool lathe can't do this. Hence you'll be limited to working with small stocks.
Swiss lathes are also compatible with live tools. It allows you to perform complex jobs. But programming them is more challenging than a gang tool lathe.
Gang tool lathes are employed on applications where multiple operations are to be performed on the same part.
Because of their ability to machine complex parts, gang tool lathes are used in manufacturing automobile parts, medical devices, and firearm parts.
Since gang tool lathes are CNC integrated, you can program the sequence of operations depending on the part design and material you use.
Gang tool lathe allows you to make high-precision parts. It can be used as a standby lathe in case of bottlenecks in the production line.
You can compensate for the damage to a machine by incorporating that operation into the gang tool lathe.
An example is shaft machining which involves turning, milling, and boring machining cycles.
Depending on the requirements, the operations can be done using a combination of gang tooling and live tooling setup.
A gang tool lathe offers great production efficiency in a mass-production environment. However, in small-scale production, the cost may be too high to be recovered from the limited batch size.
Frequently Asked Questions
Can live tooling be accommodated in a gang tool lathe?
Yes, live tooling can be accommodated in a gang tool holder using additional fixtures. This further increases the versatility of the machine.
Can you machine irregularly shaped stocks in a gang tool lathe?
Yes, irregularly shaped stocks can be machined using a gang tool lathe with the help of dedicated work-holding devices tightly secured to the chuck.
What is a CNC lathe tool?
A CNC lathe tool is a machine tool that machines cylindrical rotating parts. The workpiece is connected to a spindle that rotates them in a stable position while a cutter is laid on the workpiece to shape it into the desired shape.