-33-
Model M1112 (For Machines Mfd. Since 12/20)
O
PE
R
ATIO
NS
While other thread pitches may be achieved, the Model
M1112 is designed so that gear changes are not needed for
cutting inch threads. However, you will have to move the
feed direction lever to the direction of thread you want
to cut, and then move the feed rod lever to the right. To
get the needed threads in inches, you will then use the
standard thread chart (
Figure
46) to determine which
positions to move the quick change levers.
Example:
If the desired threads are 11 threads per inch (
Figure
46),
move the quick change gearbox levers to positions
B
and
5
. As the thread dial chart shows, engage the half-nut
when the thread dial reads
1
or
3
and begin your first
cut.
When the cut is complete, disengage the half-nut and
manually return the carriage to the beginning of the cut.
Watch the dial. When the
1
or the
3
on the dial comes
around to the indicator mark, engage the half-nut. Begin
your second pass. Repeat this process until the desired
depth of cut is achieved.
Figure
46
.
Standard thread chart.
This lathe can cut 29 different metric threads, but gear
changes are required to cut all of the listed metric
threads. These gear changes take place on the left hand
end of the machine (
Figure
47).
The chart is divided into 3 main columns, starting from
the left: Gear diagram, Combination of Gears and
m
/
m
Per
Pitch.
To use the chart, do these steps:
1.
Find the desired pitch in the chart (
Figure
48).
2.
Below the
m
/
m
Per Pitch label are numbers. Find the
corresponding number above the desired pitch and
change the right hand quick change lever to that
position.
Note:
The holes on the quick change gearbox are
letterd and numbered from left to right.
3.
To the left of the desired pitch is a small column
with a letter. This letter indicates placement of the
left hand quick change lever. Move the lever to the
corresponding location.
Change Gears & Metric
Threading
Figure
47
.
Change gear locations.
91-Teeth
86-Teeth
G
Figure
48. Metric thread chart.
F
