Setting The Spindle Speed; Milling; Setting The Depth Of Cut - Proxxon FF 400 User Manual

3. Feed the union nut 2 with the collet into the
spindle 1 (Fig. 11, see small picture) and tighten
gently by hand.
4. Feed the shaft of the tool 3 into the collet.
5. Tighten the union nut with the help of the spanner
provided as shown in Fig. 11.
6. To remove the collet, slacken the union nut and
withdraw the tool 3.
7. Now completely remove the union nut with the
collet 2 from the milling spindle.
8. Disengage the collet with the tubular section 6 pro-
vided (Fig. 12) by pressing on the cone of the collet
and remove from the union nut.

Setting the spindle speed

It is necessary to set the spindle speed in order to match
the cutting speed of the tool to the characteristics of the
material to be machined and to the tool geometry. For a
given speed, large tool diameters also mean a large cir-
cumferential speed and, under certain circumstances, too
great a cutting speed. The reverse naturally applies for
small tool diameters. It is therefore necessary to be able
to vary the speed. For this purpose, the motor power in
the milling machine is transmitted to the spindle by means
of a belt drive. This is a two-stage gear with a counters-
haft for general speed reduction and two pulley wheels,
whereby each corresponding pair has a different diame-
ter. These are connected by a total of 2 poly V-belts,
which are outstandingly suitable for this application due to
their silent running and transmission characteristics. The
required spindle speeds are obtained by appropriate posi-
tioning of the belts. A total of 6 spindle speeds can be set:
180, 350, 550, 800, 1300 and 2500 rpm. Fig. 15 shows
the appropriate pulley combinations for the individual
speeds.
Caution!
Be sure to remove the plug from the socket! Risk of
injury!
1. Slacken the knurled screw 1 (Fig. 13) and hinge up
the housing cover 2.
- 16 -
2. Slacken the fixing screws 1 (Fig. 14) slightly and
move the housing a little to the right until the lower
V-belt is loose.
3. Move the lower V-belt 2 to the appropriate position.
Follow the sticker on the inside of the housing.
4. Move the housing back to the left until the V-belts
are correctly tensioned and retighten the fixing
screws (1).
5. Close the housing cover once more and retighten
the knurled screw 1 (Fig. 13).
Caution:
The belt cover and housing cover must always be
closed during operation!

Milling

Caution!
Almost wear protective goggles when milling. Be sure
to observe the safety regulations!
As a basic principle, the tool must be securely fixed for
machining whether it be on the compound table (in the
case of the FF 400) or, with the PF 400, on the milling
table of the lathe in combination with the PD 400.
Various options are available for this purpose. Particu-
larly well suited are clamping jaws (e.g. 24 257 from
PROXXON) and vices (e.g. 24 255 from PROXXON). If
partitions are to be manufactured, it is also possible to
work with indexing attachments or chuck mounting
units. Examples of clamping devices and accessories
can be found in our product brochure and, together with
further valuable information, in our "Manual for creative
model makers" (Item No. 28 996).

Setting the depth of cut

Please refer also to the section "Spindle height adjust-
ment". Here, the methods for adjusting the height of the
milling spindle for different applications are explained.
In practice, the procedure is that after securely clam-
ping the workpiece, the spindle is roughly adjusted after
clamping the milling cutter (ca. 2 mm above the work-
piece) and the milling depth is then adjusted while ma-
chining is taking place.