Grizzly G0795Z, Owner'S Manual

Page: 27 / 64

Model G0795Z (Mfd. Since 06/17)
-25-
Setting Spindle
Speed
Using the correct spindle speed is important for
safe and satisfactory results, as well as maximiz-
ing 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 high/
low range knob and variable-speed spindle dial to
produce the required 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 cutting tool, as noted in the formula shown in
Figure 24.
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, pro-
vide 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 many spindle-speed calculators on
the internet. These sources will help you consider
the applicable variables in order to determine the
best spindle speed for the operation.
Cutting Speed (FPM) x 12
*
Recommended
Tool Dia. (in inches) x 3.14
=
Spindle
Speed
(RPM)
*
Double if using carbide cutting tool
Figure 24. Spindle speed formula for mill/drills.
Change spindle speed ONLY when the
spindle is completely stopped. Otherwise,
machine damage could occur.
Setting Spindle Speed
1. Shift high/low range knob (see Figure 25) to
either "L" (spindle speeds 50–1000 RPM) or
"H" (spindle speeds 100–2300 RPM).
Note: If necessary, rotate spindle by hand to
mesh gears when changing ranges.
2. Rotate variable-speed spindle dial fully coun-
terclockwise to set spindle speed at lowest
value.
3. Rotate E-Stop button fully clockwise to enable
power.
4. Press Power button, then select Forward or
Reverse button, and set Drill/Tap switch suit-
able for your operation.
5. Watch digital spindle speed tachometer and
adjust variable-speed spindle dial as needed
until desired RPM is reached.
Figure 25. Spindle speed controls.
High/Low
Range
Knob
E-Stop
Button
Drill/Tap
Switch
Reverse
Button
Forward
Button
Power
Button
Digital Spindle
Speed
Tachometer
Variable-Speed
Spindle Dial