Spindle Speed Selection; Manual Turning; Thread Cutting; Drilling Operation - Promac BD-7 Operating Instructions Manual

6.4 Manual turning

Apron travel (L, Fig 8), cross travel
(M) and top slide travel (F) can be
operated for longitudinal and cross
feeding.
Fig 8
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.
When roughing big diameters
reduce the depth of cut!

6.5 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.
A) To cut threads
Set the machine up for the desired
threading pitch (see chapter 7.1) and
first depth of cut.
Engage the halve nut (N, Fig 8).
The halve nut must be engaged during
the entire threading process.
- Start the machine at the lowest
spindle speed.
- When the tool reaches the end of cut
stop (reverse) the motor and at the
same time back the tool out of the
part so that it clears the thread
- 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 threads with pitch
0,5/ 0,75 /1,5 mm:
The halve nut can be opened at the
end of cut, rather than the motor being
stopped and reversed.

6.6 Drilling operation

Use a drill chuck with MT-2-short
arbor (option) to hold centring drills
and twisted drills in the tailstock.
Fig 9
For recommended speeds refer to
section 6.3
To eject the drill chuck, fully retract
the tailstock quill.

7. Setup and adjustments

General note:
Setup and adjustment work may
only be carried out after the
machine is protected against
accidental starting by pulling the
mains plug.

7.1 Change gear setup

Unplug the machine from the power
source.
Loosen the locking screw on the
pulley cover, then open the cover.
The rotational speed of the lead
screw, and hence the rate of feed of
the cutting tool, is determined by the
gear configuration.
Assemble the gears with desired setup
(Fig 10, Fig 11)
5
Fig 10
Metric Threads:
Inch Threads:
Fig 11