Backlash is the amount of play found in a lead
screw. It can be found by turning the cross slide
handwheel in one direction, then turning the
handwheel the other direction. When the cross
slide begins to move, the backlash has been
Note: Avoid the temptation to overtighten the
cross slide backlash screw. Overtightening will
cause excessive wear to the sliding block and
Backlash is adjusted by tightening or loosening
the screw shown in Figure 96.
Figure 96. Cross slide backlash adjustment cap
This screw draws a wedge-type nut against the
lead screw and main nut. If it is too tight, loosen
the screw a few turns and tap the cross slide a
few times with a rubber or wooden mallet. Then
turn the handle slowly back and forth until the
handle turns freely. To readjust the backlash, rock
the handle back and forth and tighten the screw
slowly until the backlash is at between 0.001" to
0.002" as indicated on the handwheel.
Note: Reducing backlash to less than 0.001"
is impractical and reduces the life of the cross
When adjusting gibs (Figures 98 and 42), the
goal is to remove sloppiness in the ways without
causing the slides or half nut to bind. Loose gibs
will cause a poor finish on the workpiece and
wear the slide. Tight gibs will damage the slide,
lead screw, and half-nut. The cross slide gib is
a tapered piece of iron. When the opposing front
and rear gib adjustment screws are turned in
opposing directions, the screws force the tapered
gibs to fill the void in the way, thus tightening the
play in the cross slide. If more play is needed turn
the screws the other direction.
For the three saddle gibs, (Figure 98) loosen
the jam nuts and turn the three set screws until
slight tension is felt and the gib plates are slightly
pre-loaded against the underside of the flat-way.
Tighten the jam nuts when finished.
Compound Rest Gib Adjustment Points
Cross Slide Gib Adjustment Points
Figure 98. Gib adjustment points.
Half Nut Gib
(Thread Dial Removed)
Figure 42. Half-nut saddle gib locations.
G0602 10" X 22" Benchtop Lathe