Thread Cutting; Drilling Operation; Setup And Adjustments; Change Gear Setup - Promac GHB-1330 Manuel Utilisateur

For example :
Longitudinal OD-turning, mild steel of 25mm diameter with a
carbide tool at 1255 RPM and with rigid chucking.
Stock removal and roughing cut
Depth of cut
Feed per revolution
(change gear box position B, D and R)
Finishing cut :
Depth of cut
Feed per revolution
(change gear box position A, D and R)
Micro finishing and calibration cut
Depth of cut
Feed per revolution
(change gear box position B, C and R)
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.
Move the knob (D, Fig 17) to «
rod rotation.
Set the feed rate selectors (M, N, O, P, Fig 17) in proper
position.
F
G
M
O P N
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 (H, Fig 16).
The halve nut must be engaged during the entire threading
process.
:
1,5mm
0,2mm
0,5mm
0.1mm
:
0,2mm
0.05mm
0
» to stop unnecessary feed
E
A
B
C
D
Fig 17
- Start the machine at the lowest spindle speed.
- When the tool reaches the end of cut, stop the motor and at
the same time back the tool out of the part so that it clears the
thread (Attention inertia: Stop the motor in time)
- Reverse the motor direction to allow the cutting tool to travel
back to the starting point.
Repeat these steps until you have obtained the desired
results.
B) To cut metric threads with threading dial:
On most metric threads the threading dial (G, Fig 7) can be
used.
The halve nut can be opened at the end of cut, rather than the
motor being stopped and reversed.
The halve nut may only be engaged at the corresponding
graduation match on the threading dial.

6.7 Drilling operation

Use a drill chuck with MT 3 arbour (option) to hold centring
drills and twisted drills in the tailstock.
For recommended speeds refer to section 6.4
To eject the drill chuck, fully retract the tailstock quill.

7. Setup and adjustments

Warning :
Setup and adjustment work may only be carried out after
the machine is protected against accidental starting.
Press emergency stop button!

7.1 Change gear setup

Note :
The installed 36T x 127T x 48T gears will cover most feeds
and metric threads.
The additional gears found in the toolbox are used for inch
threads and some feeds.
Disconnect the machine from the power source.
Loosen the locking screw on the pulley cover, then open the
cover.
-Loosen screw (D, Fig 18) and hex nut (F) to disengage the
quadrant.