Proxxon PD 400 Translation Of The Original Operating Instructions Download

Page: 18 / 112

- 18 -

Example of longitudinal turning

Longitudinal turning designates the turning of a cylindrical
workpiece parallel to the turning axis. The following paragraph
explains work with the lathe to the beginner using the exam-
ple of longitudinal turning.

Clamp a short workpiece in the lathe chuck as described
above (remove the key from the chuck).

Set the belt transmission to the correct speed (note table on
gearbox and Fig. 6).

Disengage the leadscrew (leadscrew switch

(Fig. 2) to left)

and engage the support (lever

(Fig. 3) downwards).

Now move the support from the right to the left close to the
workpiece (handwheel

(Fig. 1)).

Before switching on the machine, check that the chuck moves
freely by twisting the chuck by hand.

Switch on the machine (direction switch

(Fig. 2) to right).

Set the cutting depth by moving the cross-slide (handwheel

(Fig. 3)). It is best to start with a cutting depth of 1/10 mm
(4 graduations on the scale).

Now move the support in the working direction by turning the
handwheel

(Fig. 1) at the rear. If all settings are correct, the

machine works smoothly and without excessive loading.

Important

Risk of injury. When turning, always keep your fingers away
from the rotating workpiece. Never measure the workpiece
with a calliper gauge or a similar tool when the machine is
running. Do not apply a file or emery cloth to the workpiece
when the machine is running.

Taper turning

To turn tapers, the top slide is adjusted according to the desi-
red angle.

1. Move top slide to the right with handwheel

(Fig. 11).

2. Loosen clamping screws

3. Adjust the angle of the top slide and re-tighten the screws.

Note:

The top slide is equipped with a vernier scale (similar to a cal-
liper gauge). The correct angles are indicated on the outer
scale

(Fig. 11a). On the inner scale

, they are compressed

(1 graduation on the inner scale corresponds to 4.5°). The
angle can be read in 5° stages by aligning the zero mark of
the inner scale with the outer scale. If you wish to add 1°, the
“2” on the inner scale must be aligned 10° further outwards
on the outer scale. For 2°, the “4” must be aligned 20° further
outwards etc. In this example, the “2” is aligned with the “20”,
or 10° further outwards than the basic value of 10°. This pro-
duces an angle of 10°+1°=11°.

4. Clamp support with screw

(Fig. 11).

5. The feed is advanced via the handwheel of top slide

Note:

A precise taper is only achieved when the height of the
turning tool is adjusted exactly to the centre position.

Grooving and parting off a workpiece

Grooving designates the production of fine grooves. If the
groove is continued to the middle of the workpiece, this is cal-
led parting off. Ensure that the height of the parting-off tool is
adjusted to the centre of the workpiece and clamp the tool as
short as possible. Use a small turning tool and lubricate the
tool with a little machine oil if possible.

Machining longer work pieces with tailstock and
centre

Longer workpieces (chuck projection greater than 3 times the
workpiece diameter) must be held at the right hand end by the
tailstock and the travelling centrepoint. For this purpose,
provide a centrebore on the right hand face:

1. Turn the face of the right hand end carefully.

2. Insert chuck

(Fig. 12) in the tailstock and clamp a centring

bit.

3. Move the tailstock to the workpiece and fasten with clam-

ping screw

4. Switch on the machine and make the centrebore using the

sleeve feed (handwheel