OPERATI ON I N STRUCTI ON S
HOLZMANN Maschinen Austria
www.holzmann-maschinen.at
Seit e 3 5
Metalldrehmaschine / metal turning lathe ED 750 FDQ
1 5 .1 1 t aper t urning by set t ing t he t op slide
By angling the top slide, tapers may be turned manually with
the top slide. (Fig.14)
Rotate the top slide to the required angle. A graduated scale
permits accurate adjustment of the top slide. The cross feed
is performed with the cross slide. This method can only be
used for short tapers.
1 5 .1 2 Thread cut t ing
Set the machine up to the desired thread pitch (according to
the threading chart, (Fig. 14). Start the machine and engage
the half nut. When the tool reaches the part, it will cut the
initial threading pass. When the tool reaches the end of the
cut, stop the machine by turning the motor off and at the
same time back the tool out of the part so that it clears the
thread. Do not disengage the half nut lever. Reverse the
motor direction to allow the cutting tool to traverse back to
the starting point. Repeat these steps until you have ob-
tained the desired results.
1 5 .1 2 .1
Exam ple: M ale t hread
The workpiece diameter must have been turning to the
diameter of the desired thread.
The work piece requires a chamfer at the beginning of
the thread and an undercut at the thread runout.
The speed must be as low as possible.
The change gears must have been installed according to
the required pitch.
The thread cutting tool must be exactly the sample
shape as the thread, must be absolutely rectangular
and clamped so that it coincides exactly with the turn-
ing center.
The thread is produced in various cutting steps so that
the cutting tool has to be turning out of the thread
completely (with the cross slide) at the end of each cut-
ting step.
The tool is withdrawn with the leadscrew nut engaged
by inverting the change-over switch..
Stop the machine and feed the thread cutting tool in
low cut depths using the cross slide.
Before each passage, place the top slide approximately
0.2 to 0.3mm to the left and right alternately in order to
cut the thread free. This way, the thread cutting tools
cuts only on one thread flank with each passage. Keep
cutting the thread free until you have almost reached
the full depth of thread.
Fig.14
Fig.15
