Changing The Feed; Fitting Change Gears For Thread Cutting; Thread Cutting With The Turning Tool; Cutting Left-Hand Threads - Proxxon PD 400 Manual De Uso

You can then replace the chuck with the travelling centrepoint.
Guide the point into the centrebore and close down carefully
until any play is eliminated. Then fasten the sleeve with tommy
screw 3.

Changing the feed

In the standard version, the PD 400 is supplied with a feed of
0.07 mm/rev. To use a faster feed (0.14 mm/rev.), the gear-
wheel of shaft Z1 (5, Fig. 13) with 20 teeth must be replaced
by the gearwheel with 40 teeth in the gearbox. For this purpo-
se, please proceed as follows:
1. Switch off the machine at the main switch 25 (Fig. 1) and
open the gearbox 23.
2. Loosen screw 1 (Fig. 14) slightly and tilt wheel arm 2 down-
wards.
3. Remove clip 3 (Fig. 13).
4. Loosen shaft 4 at the square section by half a turn. Replace
the gearwheel 5 with 20 teeth by one with 40 teeth.
When changing the gearwheels, always place a strip of news-
paper between the tooth flanks before tightening the shafts.
The thickness of the paper strip should correspond to the
required tooth flank play.
5. Re-tighten the shaft, push on the clip, fold up the wheel
arm and re-tighten screw 1 (Fig. 14).

Fitting change gears for thread cutting

With the PD 400, it is possible to turn 19 different metric
threads (see table in the gearbox and Fig. 25) and inch
threads from 10 to 48 threads. To adjust the thread pitches,
the change gears must be exchanged correspondingly.
The change gears for a thread pitch of 1 mm are installed in
Fig. 14.
The table in the gearbox shows: w = 30, Z1 = -/50,
Z2 = 40/30, L = 60/-. w designates the gearwheel on the main
spindle. It is fastened to the main spindle by a stud. Z1 and
Z2 are the two shafts of the intermediate gears. The first
number always designates the front gear of the shaft, the last
number the rear gear. The rear gear with 30 teeth is therefore
firstly pushed onto the shaft Z2 and then the front gear with
40 teeth. On shaft Z1, first install the rear gear with 50 teeth
and then an intermediate ring.
L designates the gear on the leadscrew. Nut 6 must be loose-
ned to change this gear. The compensating disc 7 has exactly
the width of a gearwheel and must be mounted in front of or
behind the gear.
Note:

Thread cutting with the turning tool

Note:
For the following operations, the work piece must be machi-
ned completely and have the correct thread outer diameter.
It is advisable to turn a chamfer at the beginning of the thread
and to turn a small groove at the end of the thread. The
thread turning tool must be clamped at an angle of exactly
90°.
When cutting threads, always work at the lowest speed
(80 rpm) because otherwise the feed is too fast (risk of injury).
1. Set the turning tool to the starting position.
2. Engage leadscrew (turn leadscrew switch 1 (Fig. 15) to the
right).
3. Switch on the machine.
4. Advance the turning tool slightly by means of the cross-
slide.
5. Engage the support (lever 2 downwards).
6. When the desired thread length has been reached, retract
the cross-slide and switch off the machine at the direction
switch.
7. Wait until the chuck has stopped. Turn the direction switch
to left to return the support.
8. Advance the turning tool again and repeat the procedure
until the required thread depth is reached.
During the entire procedure, the support and the leadscrew
must not be disengaged as this shifts the pitch of the thread.
The top slide is used to improve the quality of the thread.
Advancing the thread tool is performed using the cross-slide
as described above. For this purpose, the top slide is adju-
sted by 0.025 mm (1 graduation) to the left and then to the
right. The cuttings are thus only removed from one side.
Once the full thread depth has been reached, a final full cut is
made by advancing slightly.

Cutting left-hand threads

To cut left hand threads, an additional shaft must be installed
with an intermediate gearwheel Z (Fig. 16) between Z2 and
the leadscrew, gear L. Thus, the turning direction of the lead-
screw is reversed. The number of teeth of the gear is irrele-
vant. The support runs from right to left when the chuck is
turning clockwise. The thread must therefore be made from
left to right.
Important
Note:
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