Emco compact 8, Instruction Book / Parts List

Page: 12 / 57

Screw Cutting (with change wheels)
By changing the combination of gear wheels, it is pos­
sible to cut metric, inch and module threads.
For R. H. threads it is necessary for the carriage to
travel in the direction of the headstock (normal rota­
ting direction of the workpiece with closed half-nut)
du ring trial runs.
When fitting the change gears and the special bolt, make
sure that the teeth mesh properly and do not bottom.
As an aid in mounting, a strip of paper should be pla­
ced between the meshing teeth and only removed
when the special bolt is tightened. This will ensure
that the wheels have the correct engagement.
It is essential that the half-nut should remain closed
throughout the screwing operation, so that the tool
always returns to the correct starting position. The
tool should be withdrawn by use of the cross slide and
the carriage returned to the starting position by rever­
sing the motor.
An exeption is the cutting of metri c threads, using the
leadscrew. In this case, after each cut the half-nut can
be opened and the carriage returned to the starting
position by use of the handwheel, i. e. 1,5 - 0,5.
Example of mounting the gear wheels for 1 mm metric thread
1. After loosening the screw 1, swing the quadrant forward.
2. Remove both washers 2 and loosen the special bolt 3.
3. Remove the hex-headed screw and the safety washer 5 from the leadscrew. Now take off the distance bush
6 and gear wheel 7.
4. Fit the bush and gear wheel (teeth= 75) on the leadscrew, secure with hex-headed screw and safety washer.
5. Mount the gear wheel, teeth= 40, on the bottom bolt and gear wheel, teeth= 80, on the top bolt. Next the
gear wheel teeth= 50 is fitted to the bottom bolt and the distance bush fitted to the top bolt.The gears are
brought into mesh as previously described and secured in place by the bolt and washer.
6. Swing the quadrant backward until it is correctly positioned with the leadscrew and fix with the screw 1.
11