South bend SB1049, Manual

Page: 55 / 136

For Machines Mfg. Since 5/11 13" Heavy 13
®
Gearhead Lathe
-49-
O P E R A T I O N
Manual Feed
The handwheels shown in Figure 64 allow the
operator to manually move the cutting tool.
Carriage Handwheel
The carriage handwheel moves the carriage left
or right along the bed. It has a graduated dial
with 0.01" increments, and one full revolution
moves the carriage 0.80". Pull the handwheel out
to disengage it during power feed operations—
this will prevent entanglement hazards.
Cross Slide Handwheel
The cross slide handwheel moves the tool toward
and away from the work. Adjust the position of
the graduated scale by holding the handwheel
with one hand and turning the dial with the
other. The cross slide handwheel has a direct-
read graduated dial which means that the
distance on the dial reflects the amount removed
from the diameter of the workpiece. The dial
has 0.001" (0.02mm) increments, and one full
revolution moves the slide 0.100" (5.08mm).
Rotate the dial collar 180° to read in metric
units.
Compound Rest Handwheel
The compound rest handwheel moves the cutting
tool linearly along the set angle of the compound
rest. The compound rest angle is set by hand-
rotating it and securing in place with two hex
nuts. The compound rest has an indirect-read
graduated dial with 0.001" (0.02mm) increments.
One full revolution of the handwheel moves the
slide 0.100" (2.54mm). Rotate the dial collar 180°
to read in metric units.
Spindle Speed
Using the correct spindle speed is important
for safe and satisfactory results, as well as
maximizing tool life.
To set the spindle speed for your operation, you
will need to: 1) Determine the best spindle speed
for the cutting task, and 2) configure the lathe
controls to produce the required spindle speed.
Determining Spindle Speed
Many variables affect the optimum spindle speed
to use for any given operation, but the two most
important are the recommended cutting speed
for the workpiece material and the diameter of
the workpiece, as noted in the formula shown in
Figure 65.
Cutting speed, typically defined in feet per
minute (FPM), is the speed at which the edge of a
tool moves across the material surface.
A recommended cutting speed is an ideal speed
for cutting a type of material in order to produce
the desired finish and optimize tool life.
The books Machinery’s Handbook or Machine
Shop Practice, and some internet sites, provide
excellent recommendations for which cutting
speeds to use when calculating the spindle speed.
These sources also provide a wealth of additional
information about the variables that affect
cutting speed and they are a good educational
resource.
Also, there are a large number of easy-to-use
spindle speed calculators that can be found on
the internet. These sources will help you take
into account the applicable variables in order
to determine the best spindle speed for the
operation.
Cutting Speed (FPM) x 12
*
Recommended
Dia. of Cut (in inches) x 3.14
= SpindleSpeed (RPM)
*
Double if using carbide cutting tool
Figure 65. Spindle speed formula for lathes.
Figure 64. Carriage Controls.
Carriage
Handwheel
Cross Slide
Handwheel
Compound
Rest
Handwheel