7
Fig 13
Face locate the workpiece for added
support.
6.3 Tool setup
The cutting angle is correct when the
cutting edge is in line with the centre
axis of the work piece. Use the point of
the tailstock centre as a gauge and
shims under the tool to obtain the
correct centre height.
Use a minimum of two clamping
screws when installing the cutting tool
to the four way tool post.
Avoid big tool extensions.
6.4 Spindle speeds selection
The correct spindle speed depends on
the type of machining, the cutting
diameter, the material to be machined
and the cutting tool.
These are recommended max. speeds
for a 50mm cutting diameter with
carbide (HM) tools:
Aluminium, brass
1500 RPM
Cast iron
1000 RPM
Mild steel
800 RPM
High carbon steel
600 RPM
Stainless steel
300 RPM
If high speed steel (HSS) tools are
used about 5 times lower speeds must
be chosen.
Generally speaking, the larger in
relation the cutting diameter, the
smaller the possible RPM.
For example:
Turning mild steel at a diameter of
25mm allows a speed of
1600 RPM max.
with carbide tool
320 RPM max.
with HSS tool
To change the spindle speed:
The speed may never be changed
when the spindle or motor are still
running.
Move the speed select levers (E, Fig
6) according to the speed you desire.
It may be necessary to turn the chuck
by hand to help the gears to engage.
6.5 Turning with auto feed
Several automatic longitudinal and
cross feeds are readily available by
selection on the gearbox handles (G,
H, J, Fig 14).
The gearbox selector handle (J) may
only be adjusted when the lock knob
(I) is in the 9 o’clock position. With the
lock knob in the 3 o’clock position the
selector handle (J) is locked.
Fig 14
The feed direction can be chosen with
the feed reversing lever (F, Fig 14).
Move the lever (B, Fig 15):
- right and up for longitudinal feed.
- left and down for cross feed.
Fig 15
The correct feed depends on the
material to be cut, the cutting
operation, the type of tool, the
rigidity of the work piece chucking,
the depth of cut and the desired
surface quality
.
For example:
Longitudinal OD-turning, mild steel of
25mm diameter with a carbide tool at
1280 RPM and with rigid chucking.
Stock removal and roughing cut:
Depth of cut
2mm
Feed per revolution
0,2mm
(change gear box position blue, 2 and
S )
Finishing cut:
Depth of cut
0,5mm
Feed per revolution
0.1mm
(change gear box position blue, 8 and
U)
Micro finishing and calibration cut:
Depth of cut
0,2mm
Feed per revolution
0.05mm
(change gear box position blue, 1 and
U)
When roughing big diameters reduce
the depth of cut!
6.6 Thread cutting
Threading is performed in multiple
passes with a threading tool.
Each depth of cut should be about
0,2mm and become less for the
finishing passes.
Set the feed rate selectors (A, B, C, D,
Fig 16) in proper position.
Fig 16
Move the knob (I, Fig 14) to engage
the lead screw.
A) To cut inch and metric threads
Set the machine up for the desired
threading pitch and first depth of cut.
Engage the halve nut (C, Fig 15).
The halve nut must be engaged during
the entire threading process.
