The lathe is one of the machines most commonly used in small mechanical industries and repair workshops. One of the most common or traditional types is the parallel lathe. Easy to use, numerous operations of the parallel lathe are known today for different applications.
The main use of the parallel lathe is to transform a solid object into a piece of predefined shapes and dimensions. To do this, the object is rotated around the axis of symmetry of the parallel lathe. Thus, chips are removed, the solid material of the object is shaped as required.
The most common operations of the parallel lathe
The parallel lathe is used to cut and turn metal (that is, to shape it). It is an indispensable mechanical drive tool in any machining workshop, as it allows for numerous specific tasks to be performed.
Drilling with Parallel Lathe
Drilling is one of the most used operations of the parallel lathe in any machining workshop. What is done here is chip removal with a circular cutting motion using helical drills. For this, the lathe employs a feed motion in the direction of the rotation axis.
Generally, drilling with a parallel lathe is carried out on the piece in combination with other lathe work. This way, one side of the piece can be drilled, taking advantage of it being perfectly secured. Special care must be taken in cases where the drill is small.
Parting with Parallel Lathe
Parting with the parallel lathe is an operation that involves cutting or separating part of a piece. This task is usually performed in the machining of small-sized parts and with machines that have bar feed.
Parting is typically one of the last operations on the parallel lathe. That's why special care must be taken and a precision tool should be used; it is also recommended to do it with a coolant, either manually or automatically.
Boring with parallel lathe
Boring is a machining operation carried out on holes in parts to achieve greater precision and lower surface roughness. In this case, the size of the hole must be carefully considered to perform the work. However, it can be done on both cylindrical and conical holes. Conical boring is recommended to be done with CNC lathes, as it requires a lot of skill to do it with manual lathes.
With boring, the goal is to enlarge or improve the quality of an existing hole.
Facing with parallel lathe
Facing is an operation that involves machining the end of a piece and on the plane perpendicular to the axis of rotation of the parallel lathe. The operator must position the piece at a 120-degree angle with respect to the tool holder. This way, a flat surface is obtained by allowing the tool to advance through the front face of the piece.
Meanwhile, the piece rotates and is usually held by a vise. Facing can be done from the outside in or from the center out.
Threading with parallel lathe
Threading with a parallel lathe is one of the most demanding operations. The cutting forces are higher, and the cutting radius for threading is smaller. The feed rate in this machining process must match the thread pitch. Therefore, to carry out this operation, the desired thread profile is usually pre-adapted.
When it is necessary to produce large quantities of threaded parts, thread rolling is used (instead of the traditional chip removal) or threading with numerically controlled lathes. The difference here is that the fibers of the material are not cut but displaced. This reduces manufacturing times and increases the longevity of the lathe.
Cylindrical turning or turning
Cylindrical turning or turning is another operation of the parallel lathe. It can be of two different types:
- External turning: the tool moves longitudinally along the piece and parallel to the machine's axis, resulting in a smaller diameter than the original
- Internal turning: same tool movement as the previous one, but in this case resulting in a larger diameter than the original
To ensure maximum quality in this operation, the parallel lathe must have its alignment and centricity well adjusted.
Taper turning
Taper turning is a machining operation that involves working on revolution surfaces with generatrices that are not parallel. This task can be performed on the parallel lathe using three different methods:
- The method using the top carriage
- With a conical turning device
- Moving the tailstock
Alongside these operations of the parallel lathe, others that can be performed are knurling, reaming, or grooving.
