Setting Spindle Speed - Grizzly G0678 Owner's Manual

Setting Spindle
Speed
To select the correct spindle speed (RPM) for your
milling operation, you will need to: 1) Determine
the spindle speed needed for your workpiece, and
2) set the speed dial for the calculated speed.
Calculating Spindle Speed
1. Use the table in Figure 21 to determine the
cutting speed or surface feet per minute
(SFM) required for your workpiece material.
Cutting Speeds for High Speed Steel (HSS)
Cutting Tools
Workpiece Material
Aluminum & alloys
Brass & Bronze
Copper
Cast Iron, soft
Cast Iron, hard
Mild Steel
Cast Steel
Alloy Steel, hard
Tool Steel
Stainless Steel
Titanium
Plastics
Wood
Note: For carbide cutting tools, double the cutting
speed. These values are a guideline only. Refer to
the MACHINERY'S HANDBOOK for more detailed
information.
Figure 21. Cutting speed table for HSS cutting
tools.
2.
Measure the diameter of your cutting tool in
inches.
3. Use the following formula to calculate the
required spindle speed (RPM) for your opera-
tion:
*
Recommended
Cutting Speed (FPM) x 12
Tool Dia. (in inches) x 3.14
*
Double if using carbide cutting tool
Model G0678 (Mfd. Since 06/15)
Cutting Speed (SFM)
300
150
100
80
50
90
80
40
50
60
50
300-800
300-500
Spindle
=
Speed
(RPM)

Setting Spindle Speed

1.
Rotate the speed dial all the way to the left,
setting the startup spindle speed close to
zero.
Note: This precaution avoids unexpected
high speed startup of the spindle.
2.
Use the direction switch to select the direc-
tion of spindle rotation, turn the spindle ON,
then rotate the speed dial until the calculated
spindle speed is displayed on the digital read-
out on the control panel (see Figure 22).
Direction
Switch
Digital
Readout
Speed
Dial
Figure 22. Spindle direction switch, speed dial,
and digital readout.
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