Spindle Downfeed - Grizzly G0731 Owner's Manual

Spindle Downfeed

Spindle downfeed movement on the mill is
controlled by two mechanisms: 1) The coarse
downfeed lever, and 2) the fine downfeed
handwheel. Refer to Downfeed Controls on
Page 4 for detailed descriptions of all downfeed
controls and components.
Using Coarse Downfeed
Coarse downfeed is typically used for drilling,
because it allows you to quickly lower the spindle
with varying speed/pressure, and it automati-
cally retracts the spindle to the top position when
released.
To use coarse downfeed, make sure the spindle is
completely stopped. Loosen the downfeed selec-
tor, and then rotate the coarse downfeed handle
around the hub to control spindle depth (see
Figures 34–35).
Note: To maintain control of the upward spindle
travel, always continue holding the handle until
the spindle returns to the top position. Letting go
of the handle too soon will cause the spindle to
retract too quickly and slam up into the headstock.
Downfeed
Selector
Figure 34. Location of downfeed selector.
Fine Downfeed
Handwheel
Figure 35. Location of fine and coarse downfeed
controls.
-30-
Using Fine Downfeed
Fine downfeed is used for precise Z-axis posi-
tioning of a cutter or end-mill when milling a flat
surface across the face of a workpiece. In order
to ensure the milled surface remains flat, the quill
lock lever should be locked after each adjustment
to ensure the spindle height cannot move until the
entire milling operation is complete.
To use fine downfeed, make sure the spindle is
completely stopped. Tighten the downfeed selec-
tor, and then rotate the fine downfeed handwheel
to raise or lower the spindle (see Figures 34–35).
Setting Downfeed Stop
The downfeed stop sets the depth of spindle
travel for repeat operations.
To set downfeed stop:
1.
2.
3.
Quill Dog
Downfeed Stop
Locking Wheel
Figure 36. Location of downfeed stop controls.
Coarse
Downfeed
Handle
Lower spindle to desired depth, then lock
quill.
Rotate downfeed stop until it contacts quill
dog, then tighten locking wheel against stop
to secure it (see Figure 36).
Release quill lock and raise quill (see
Figure 36).
Quill Lock
Model G0731 (Mfd. Since 01/17)