Graduated Dials; Backlash; Column Angle Adjustment - Grizzly G8689 Owner's Manual

Graduated Dials

The handwheels and the micro-downfeed adjust-
ment knob have graduated dials. Each mark
represents 0.001" of movement and one full revo-
lution of the micro-downfeed knob equals 0.060"
The graduated dials float and can be indexed or
"zeroed". One full revolution of the handwheel
equals 0.0625".
Example:
Suppose you want to drill a series of holes with
⁄ " centers (0.500"). After locating the first hole
1
2
placement and drilling, you would zero the gradu-
ated dial of the appropriate axis, move the table
0.500" in that direction and drill the next hole.

Backlash

The subject of backlash and graduated dials are
somewhat interconnected. When you change
direction of the table in either axis, you must cor-
rect the graduated dial for backlash.
To correct for backlash:
1.
Turn the handwheel and move the table the
opposite direction of your next operation.
2.
Turn the handwheel to move the table in the
intended direction.
3.
The exact moment the lead screw catches
and the table begins to move, backlash has
been eliminated and the graduated dial can
be "zeroed."
Note: You will not need to adjust for back-
lash as long as the table keeps moving in the
same direction.
G8689 Mini Mill (Mfg. 8/06+)
Column Angle
Adjustment
For machining operations requiring an angle, the
column of the Model G8689 can be adjusted up to
45° in either direction of the vertical axis.
To adjust the angle:
1. Make sure the mill is securely fastened to
your workbench or table as described on
Page 15.
2. Using the 36mm wrench, loosen but do not
remove the column adjuster nut and support
the weight of the head with your free hand.
3.
Position the head and column to the desired
angle and tighten the nut (see Figure 16).
Note: If a high degree of accuracy is required,
use additional methods for confirming the angle.
A falling head can crush or pinch. Keep the
head supported when loosening the lock-
ing bolt and positioning head. If this cau-
tion is ignored moderate personal injury
could occur.
Figure 16. Supporting head during positioning.
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