Chuck Runout - Grizzly G4000 Instruction Manual

C C h h u u c c k k R R u u n n o o u u t t
If your lathe use requires a higher level of accu-
racy, you may find it necessary to true-up the
chuck to ensure minimal runout. To check and
correct runout:
1 1 . . Mount a piece of bar stock in the chuck.
The stock should protrude approximately
2''.
2 2 . . Using a dial indicator, measure the run-out
at the end of the bar. In most cases, the
amount of runout will not exceed .005" over
2" which should be accurate enough for
most applications. If the runout on the
chuck is excessive (e.g., greater than
.006"), the excess runout should be elimi-
nated.
3 3 . . Start by removing the chuck.
4 4 . . Remove the mounting bolts that hold the
back-plate to the chuck. Tap along the
edge of the mounting shoulder until the
chuck and back plate are free of each
other.
5 5 . . Thread the back plate onto the spindle.
6 6 . . Remove about .005'' of material from the
surface that the chuck mounts to. Be care-
ful not to remove any material from the
diameter of the shoulder. F F i i g g u u r r e e 2 2 7 7 . .
-20-
F F i i g g u u r r e e 2 2 7 7 . . Truing the back plate.
7 7 . . Install the chuck onto the back plate and
check the run-out. If the runout is not within
an acceptable range, it may be necessary
to turn a new shoulder on the back plate.
8 8 . . Before turning a new shoulder, accurately
measure the diameter of the recess in the
back of the chuck.
9 9 . . Remove approximately one half of the
thickness of the shoulder (approximately
1
⁄ "). Remove the same thickness off the
16
face of the mounting surface. F F i i g g u u r r e e 2 2 8 8 . .
F F i i g g u u r r e e 2 2 8 8 . . Turning new shoulder on back plate.
G4000 9'' x 19'' Lathe