For Machines Mfg. Since 7/09
EVS Toolroom Lathes
-43-
O P E R A T I O N
Manual Feed
You can manually move the cutting tool around
the lathe for facing or turning operations using
the handwheels shown in
Figure 77
and
described below.
Carriage Handwheel
The carriage handwheel moves the carriage left
or right along the bed. Use this control when
setting up the machine for facing or turning.
Cross Slide Handwheel
The cross slide handwheel moves the tool toward
and away from the work. Turning the dial
clockwise moves the slide toward the workpiece.
Adjust the graduated scale by holding the
handwheel with one hand and turning the dial
with the other. The graduated scale reads in
0.001" increments and is a "direct-read" which
means that the distace on the collar reflects
the amount removed from the diamter of the
workpiece.
Compound Slide Handwheel
The compound slide handwheel controls the
position of the cutting tool relative to the
workpiece. The compound is adjustable for any
angle within its range. Angle adjustment is
secured by two nuts on the base of the compound.
The graduated scale reads in 0.001" increments
and is a "indirect-read" which means that the
distace on the collar reflects the distance that the
tool moves.
Figure 77. Carriage Controls.
Cross Slide
Handwheel
Compound Slide
Handwheel
Carriage
Handwheel
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 operations, 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 78
:
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. All of these sources will help you
take into account all 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 78. Spindle speed formula for lathes.
