Cutting Speeds; Selecting The Cutting Speed; Influences On The Cutting Speed; Example For The Determination Of The Required Speed On Your Lathe - Optimum optiturn TH 3610 Betriebsanleitung

5

Cutting speeds

5.1

Selecting the cutting speed

The variety of factors makes it impossible to present universal indications about the
"correct" cutting speed.
Tables with reference values about cutting speeds to be set must be evaluated with utmost caution since they only apply for very particular cases. The refe-
rence values without cooling (no best values) which are indicated in AWF documents are highly recommended. Furthermore, the tables of reference values of
the manufacturers of cutting materials should be evaluated e.g. for hard metal cutting materials the indications of the company Friedrich Krupp Widia-Fabrik,
Essen applies.
V is the cutting speed at 60 min. service life, V
c60
tool sets depending on one another; V
the accuracies of the cutting insert. The same considerations apply with regard to maintenance of the tools. It generally applies: High cutting speeds result in
low-time chipping, little cutting speeds result in cost-efficient chipping.
5.2

Influences on the cutting speed

v
= Cutting speed in [ m/min]
c
t
= Service life in [min]
t
The service life is the period of time in minutes during which the cutting insert performs cutting tasks until it is necessary to re-sharpen it. It is of utmost com-
mercial importance. For the same material
v t
require different for the same . All considerations of this type require that the other cutting conditions are maintained constant (material, tool and setting
c
conditions). If only one of these condition changes it is also necessary to change
reasonable which show all relevant cutting conditions.
5.3

Example for the determination of the required speed on your lathe

The necessary speed is depending on the diameter of the workpiece, of the material to be machined, of the turning tool, as well as of the setting of the turning
tool (cutting material) to the workpiece.
Material to be turned: St37
Cutting material (turning tool): Hard metal
Setting angle [k ] of the turning tool to the workpiece: 90°
r
selected infeed [f]: about 0.16mm/rev
v
the cutting speed [ ] according to the table: 180 meters per minute
c
diameter [d] of your workpiece: 60mm = 0.06m [meters]
c
180m
----------- - -------------------------------------------------- -
Speed n = =
     
d min 3 14 0 06m
Set the speed on your lathe below the calculated speed.
VC_GB.fm
according for 240 min. service life. Select V
c240
for complicated tool sets where the tool change requires more time due to the dependencies on one another and
c480
t
is smaller the higher you select the value
1 –
= 955min
for simple, easily replaceable lathe tools; V
c60
v
e.g. only a few minutes at
c
v t
in order to obtain the same . Therefore, only cutting speed tables are
c
for simple
c240
v
= 2000 m/min. Different materials
c