Basically, while the spindle axis of a vertical lathe is parallel to gravity, the spindle of a horizontal lathe is parallel to the floor, all simple so far. But these differences in its construction generate a great impact on the functionality of the machine. While the horizontal lathe types are probably better known and frequent, the advantages and possibilities of vertical lathes should not be underestimated.
In Mexico, both types of CNC lathe are widely used and their application depends on the number of pieces you need to machine per series, on the complexity of the manufacturing of the parts and their size.
The decision process to acquire some type of CNC lathe, must be taken considering at all times the production conditions within your company such as the workload, the number of work cycles required to meet the manufacturing goals, the finishing, precision and accuracy level required for the quality of the parts produced, in addition to the level of automation you want within the production process itself.
To make it easy for you to understand the main differences of the types of lathe according to the requirements that are appropriate in your business or company, following we explain the main features and benefits of the various types of CNC lathe.
Click here and send us your questions, which will help you decide which types of lathe are best for your business or company.
VERTICAL LATHE
Vertical lathes, or ‘VTL’ (Vertical Turning Lathe), are one of the most traditional machine types. Ideal for heavy machining, from medium to large pieces, which are subject to chuck or other jigs and that due to their size or weight would make it difficult to fix on a horizontal lathe. The vertical lathes manage to mechanize pieces in a range of diameters from 1 m. up to more than 20 meters (39.37 to 787.40 in.).
Let gravity to be your friend!
Within vertical lathes, the work pieces are kept in an upright position when they are “standing”, requiring much less clamping force than horizontal lathes to keep the piece in place thus avoiding deflection. More importantly, vertical lathes can be used to turn large and heavy diameter objects that are relatively short. Workpieces can include parts such as wheels or large disks, large bearings, aerospace parts, heavy castings and many more.
High productivity with vertical lathes.
Working with gravity facilitates clamping and also allows more cutting force to be applied. This increases the chip removal rate and reduces cycle times. Therefore, under these conditions, vertical turning is significantly more productive than horizontal turning. Another advantage of vertical lathes, often underestimated, is that they usually need less floor space than horizontal lathes, since their mechanical components are also located within the vertical axis. Vertical lathes rarely require a counterpoint, since the only point of attachment of the pieces is the horizontal plate on which they rest. The manipulation of the pieces to fix them on the plate is done by bridge cranes or hoists if your work is very heavy.
In the case of large vertical lathes, the guides of the vertical lathe types are mounted on two vertical parallel columns, joined at the top by a bridge. The tool carriage moves horizontally over the bridge, which in turn is guided by two columns.
Regarding Cutting Tools
It is much more common in vertical lathe systems that cutting tool holders are equipped with quick-change tool magazines, but unlike milling centers, rigidity is much more critical in turning operations, because magazines tend to be much more rigid and structurally part of the machine (on disk). But even so, changing tools can be done relatively quickly; These units allow you to change the toolholder in less than 1 minute with great precision, reducing the time of setting and pre-measurement of the tool. If what you need is to have space for more tools due to the increase in the number of operations performed and the complexity of the pieces you produce; you should look for machines with chain-type linear linear magazines such as the Brother M-140X2, similar to those of multitasking machines or large machining centers, instead of traditional disk storage.
Automatic tool change: The tools are changed automatically, which guarantees you to minimize downtime, but the rigidity of the process is at risk..
Rotary spindles: With the use of different complements, held by curved couplings or four-vertex fixings, a spindle can direct a head at multiple angles. This results in a 4-axis machining center, without the need to move large parts of a lathe to a machining center, which requires time and labor.
HORIZONTAL LATHE
Has your production lengthened in measures? The solution is a horizontal lathe!
The horizontal lathe is more suitable tool for machining parts that have cylindrical geometric shapes. These machines rotate the piece while several tools that are responsible for cutting are responsible for pushing the tool against the surface, cutting it according to the specifications.
There are things that only horizontal lathes can do. Especially when turning long pieces, where horizontal lathes show their greatest resistance. The ability to mount parts with clamps (chucks), and with a tailstock allows rotating work pieces with long shafts. Horizontal lathes may also use bar feeders.
Horizontal lathes have extreme stability but the possibilities of changing tools are much more limited than those of vertical lathes. That said, another advantage of a horizontal lathe is that gravity moves the chips away from the piece, in other words, while the piece is spinning, all chips fall into the chip conveyor or its corresponding container.
Horizontal lathes characteristics
Counterpoint / fixed toolholder: Long slender parts with internal machining require a counterpoint and a fixed toolholder instead of a secondary spindle and a lower revolver to avoid deflection. The long insert bar adapter is the natural choice depending on the length to be machined.
On a horizontal lathe, the usual magazine and automatic change are limited in terms of the length of the tool that can be changed. On larger machines, there may be a warehouse and a tool change function for long bars for machining, but on small machines the amount of tools may be limited, so an extra turning station is needed. This can be avoided with twin-spindle lathes (twin Chuck) such as the Takisawa TT series.
We will talk about Swiss type lathes on our next blog
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Regards !
Luis Daniel Arzola (daniel.arzola@yamazen.com.mx)