Turning - what is it?
Turning is a type of machining - one of the basic and most popular. In order to obtain the desired shape and dimensions of the workpiece, the turning knife separates the top layer of the material. This method of machining applies to both external surfaces (turning) and internal workpieces (boring). When separating the excess material, we obtain chips of different length and elasticity - depending on the type of the turned material - they are a side effect of turning.
Turning a solid, but is it all?
Axially rotating shapes are processed in this way. In classical machining, the turning knife is stationary (or undergoes rectilinear motion), while the workpiece - driven by the machine spindle - rotates. The surfaces of the details are most often cone-shaped or cylindrical, but they can also be curved or spherical.
Very different materials are subject to turning. This is how you can process:
· Unalloyed steel
· Low alloy steel
· High-alloy steel
· Hardened steel
· Stainless steel
· Gray cast iron, compact graphite, nodular, ductile, isothermally hardened, malleable
· Heat resistant super alloys
· Non-ferrous materials (aluminum)
Basic assumptions of the turning process
The turning process depends on various parameters such as:
Cutting volume expenditure
The hardness of the processed material
Machine time for turning
Classification of turning methods
Turning can be classified in a number of different ways. Depending on the direction of the feed movement of the knives in relation to the axis of rotation of the solid, we can distinguish:
Longitudinal turning (the direction of the feed motion is parallel to the axis of the workpiece
Boring, drilling, threading, knurling
The movements accompanying turning can be divided into:
Basic movements: main and feed movement
Auxiliary Movements: Movements to correctly locate the tool while the machine is paused
Turning can also concern:
outer surface - rolling
internal surface - boring, boring
When we take into account the type of tool - we distinguish:
Depending on the quality of the turning performed, we can divide it into:
very precise turning
When analyzing the position of the axis of rotation of the object, we notice:
In the case of conical surfaces, there are several ways to process them:
Turning according to the ruler
Turning with a shaped knife
Turning by twisting the bottom bracket
Turning by shifting the tailstock axis
Turning on CNC lathes
A lathe, also known as a machine tool, is a machine on which the turning process takes place. Until recently, in every metalworking plant it was possible to find a conventional or traditional lathe, which is now being replaced by CNC numerical machines. The CNC lathe ensures high repeatability, unquestionable precision and a fast pace of work, which is of great importance in serial production. Thanks to it, you can bring out a lot of identical details in a short time.
Lathes have machining tools - turning knives or drills. There are many types of lathes, such as: heavy, multi-tool, turret (also called revolver), carousel, disc, specialized, automatic, semi-automatic, production, special and industry-specific, and finally the most popular are CNC lathes.
The tool used for turning is the so-called turning tool. Depending on the type, they are used for the treatment of internal and external surfaces. Point knives turn point knives, form knives shape shape.
Taking into account the method of making knives, we distinguish:
uniform - completely made of one material
combined - permanently connected working part and part used for gripping
Folding knives are most often used, because in this case it is possible to change the position of the insert when the cutting surface wears out, and also to replace it when the time comes. We can distinguish these tiles due to their shape. So we have triangular, square, pentagonal plates, they may differ in size, blade geometry and the material from which they are made (superhard materials, sintered carbides, ceramics).
Depending on the cutting direction, we distinguish left, right and double-sided knives.