Southbend SB1023 用户手册

-32-

For Machines Mfg. Since 8/09

Model SB1023

Backlash is the amount of play found in a 

leadscrew. Without moving the table, the amount 

of backlash can be determined by lightly turning 

the handwheel with your fingertips in one 

direction until the handwheel stops, noting the 

location shown on the handwheel scale. Then the 

handwheel is turned in the other direction until 

it stops. The distance between both stopping 

locations is the amount of backlash. If the 

backlash exceeds 0.007", adjust it back into range 

the of 0.003" to 0.006".

The backlash adjustment is made by tightening 

or loosening the cross-feed leadscrew halfnut 

cap screws shown in Figure 42. These screws 

draw two halves of the halfnut together against 

the leadscrew placing pressure on the threads. 

If this fit is too tight, loosen the cap screws, tap 

the table a few times with a rubber or wooden 

mallet, and 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 screws slowly until the backlash is 

correct.

Note: Avoid the temptation to overtighten 

the cap screws at the leadscrew halfnut. 

Overtightening will cause excessive wear 

to the halfnut and leadscrew. Reducing 

backlash to less than 0.003" is impractical 

and reduces the life of the gib and the ways.

The gib is a tapered piece of steel that is held in 

position by a gib screw. When the screw is turned 

clockwise, the gib will be moved to fill the loose 

void in the way, thus, removing the play. If more 

play is needed, adjust the screws the opposite 

direction.

When adjusting the table or column gib screw 

(Figure 43), keep in mind that the goal is to 

remove sloppiness in the ways without causing 

the dovetailed ways to bind or prematurely wear. 

A loose gib can cause dimensional problems or a 

poor finish on the workpiece.