OPTIMUM
M A S C H I N E N - G E R M A N Y
Version 3.1.8 dated 2015-1-27
Page 27
Original operating instructions
BF20V
US
4.6
Clamping the workpieces
CAUTION!
Injury by parts flying off.
The workpiece always needs to be fixed by a machine vice, a jaw chuck or by other
appropriate clamping tools such as clamping claws.
4.7
Changing the speed range
ATTENTION!
Wait until the mill drill has come to a complete halt, before performing any changes on
the gear switch.
Select gear level
H = rapid
L = low
Adjust the speed with the
potentiometer. The speed and
thus the cutting speed
depends on the material of the
workpiece, the milling cutter
diameter and the cutter type.
Fig.4-6:
Drilling and milling head
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 optimised.
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 at higher
speeds than with tools made of high-alloyed high-speed steel (HSS). You will achieve the cor-
rect 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. Machinery's
Handbook ISBN 0-8311-2424-5, Insert Pgs. 30a & 30b (attached)).
The required speed is calculated as follows:
Selector switch gear stage
H = rapid
L = low
