Optimum BF 30 Vario Operating Manual page 25

Operation
4.7 Changing the speed range
ATTENTION!
Wait until the drilling-milling machine has come to a complete halt before changing the
speed using the gear switch.
Select gear level.
H = rapid
M = middle
L = low
Adjust the speed with the potentiome-
ter. The speed and thus the cutting
speed depends on the material of the
workpiece, the milling cutter diameter
and the cutter type.
4.8 Selecting the speed
For milling operations, the essential factor is the selection of the correct speed. The speed
determines the cutting speed of the cutting edges which cut the material. By selecting the cor-
rect cutting speed, the service life of the tool is increased and the working result is optimized.
The optimum cutting speed mainly depends on the material and on the material of the tool. With
tools (milling cutters) made of hard metal or ceramic insert it is possible to work with higher
speeds than with tools made of high- alloy high speed steel (HSS). You will achieve the correct
cutting speed by selecting the correct speed.
In order to determine the correct cutting speed for your tool and for the material to be cut you
may refer to the following standard values or a table reference book (e.g. Tabellenbuch Metall,
Europa Lehrmittel, ISBN 3808517220).
The required speed is calculated as follows:
n =
n = speed in min
V = cutting speed in m/min (meters per
minute) d = tool diameter in m (meters)
4.8.1 Standard values for cutting speeds
[ m/min ] with high-speed steel and hard metal in conventional milling.
Peripheral and side milling cutters
Relieved form cutters [ m/min ]
Inserted tooth cutter with SS [ m/min ]
Stand 16 / 09 / 2008
V
π
------------
d
-1
(revolutions per minute)
Tool
[ m/min ]
Version 1.0.3
Selector switch gear
level
Illustr. 4-5: Drill-Mill head
Steel
10 - 25
15 - 24
15 - 30
BF 30 Vario
OPTIMUM
M A S C H I N E N - G E R M A N Y
Grey cast-iron hardened
10 - 22
10 - 20
12 - 25
Drilling-Milling machine
Age-
Al alloy
150 - 350
150 - 250
200 - 300
Page 25