26
OPERATION MANUAL
Gibs are tapered lengths of metal that are
sandwiched between two moving surfaces.
Gibs control the gap between these surfaces
and how they slide past one another. Correctly
adjusting the gibs is critical to producing good
milling results.
Tight gibs make table movement more accura-
te but stiff. Loose gibs make moving the table
sloppy but easier to do. The goal of gib ad-
justment is to remove unnecessary sloppiness
without causing the ways to bind.
Gibs are adjusted with a screw on each end
of the gib, that move the tapered gib back-
and-forth to increase or decrease the friction
pressure between the sliding surfaces. The
process of properly adjusting the gibs requires
trial-and-error and patience.
Refer to Fig. 29-31 to identify the locations of
the table, saddle, and knee gibs, and one of the
two adjustment screws for each.
NOTE:
It will be necessary to remove small
parts, such as way wipers and covers, to access
the gib adjustment screws.
The following is the method used to adjust the
gibs.
1. DISCONNECT MACHINE FROM POWER!
2. Make sure all table/knee locks are loose.
3. Loosen one gib adjustment screw, then ``
tighten the other the same amount to move
the gib.
4. Use ball handles/crank to move table/knee
until you feel a slight drag in the path of
movement. Repeat Steps 3–4 as necessary.
GIB ADJUSTMENT
Fig. 29 Table Gib Adjustment
Table Gib
Fig. 30 Saddle Gib Adjustment
Saddle Gib
Fig. 31 Knee Gib Adjustment
Knee Gib
Page 26
Instructions Manual for BM-23A (M595D)
12/02/2018
