Southbend South Bend 16 SPEED GEARHEAD LATHE SB1053 - Manual (Page 55)

For Machines Mfg. Since 3/11 16-Speed Gearhead Lathe
-53-
O P E R A T I O N
4. Move the spindle speed lever so that the
indicator points to the letter "A". This will
select the spindle speed of 40 RPM in the top
row of the chart.
Example 2: Spindle Speed of 1250 RPM
1. Make sure the spindle is completely stopped
and the spindle ON/OFF lever is in the OFF
(middle) position.
2. Turn the motor switch to the HIGH (right)
position. This will make the speeds in
the bottom row of the spindle speed chart
available
3. Move the spindle range lever so that the
indicator points to the lower line (see Figure
76). This will make the last four or higher
speeds in the bottom row available.
C
B
A
D
Spindle Speed
Lever at “C”
(1250 RPM) Spindle Range
Lever at the
High Range
1000 625 375 245 165 100 60 40
2000 1250 750 490 330 200 120 80
D C B A D C B A
Figure 76. Setting the spindle speed at 1250 RPM.
4. Move the spindle speed lever so that the
indicator points to the letter "C". This will
select the spindle speed of 1250 RPM in the
bottom row of the chart.
Both the carriage and cross slide have power feed
capability when the carriage is engaged with the
feed rod. The rate that these components move
(feed rate) is controlled by how the levers are
positioned on the headstock and quick-change
gearbox, and the end gear arrangement.
Feed rate and spindle speed must be considered
together. Keep in mind that the feed rate is
expressed in the amount of travel per revolution
of the spindle. The sources you use to determine
the optimum spindle speed for an operation will
also provide the optimal feed rate to use with
that spindle speed.
Often, the experienced machinist will use the
feeds and speeds given in their reference charts
or web calculators as a starting point, then
make minor adjustments to the feed rate (and
sometimes spindle speed) to achieve the best
results.
The carriage can alternatively be driven by the
leadscrew for threading operations. However,
this section only covers the use of the power
feed option for the carriage and cross slide
components for non-threading operations. To
learn how to power the carriage for threading
operations, refer to Threading on Page 58.
Power Feed
To avoid damaging the machine, NEVER
attempt to engage carriage with leadscrew
and feed rod at the same time!
Never change spindle speeds while spindle is
moving! Severe machine damage will occur.