Southbend SB1012 User Manual

For Machines Mfg. Since 7/09

EVS Toolroom Lathes

-67-

The half nut mechanism can be tightened if it 
becomes loose from wear. The pressure exerted 
by the half nut is controlled by a gib similar to 
the one in the saddle, which is on Page 66. The 
half nut gib is adjusted with two set screws.

Hex Wrench 3mm ................................................. 1

  Disengage the half nut.

  Remove the thread dial.

  Turn the two half-nut adjustment set screws,  

shown in Figure 132, clockwise about an 

1

⁄

8

th

 

of a turn.

  Engage/disengage the half nut several times 

and notice how it feels (you may need to 
move the carriage handwheel slightly to get 
the half nut to close).

 

The half nut is correctly adjusted when it 
has a slight drag while opening and closing. 
The movement should not be too stiff or too 
sloppy.

 Repeat 

Steps 3–4, if necessary, until you are 

satisfied with the half nut adjustment. (If 
the half nut becomes too stiff, turn the set 
screws counterclockwise to loosen it.

  Re-install the thread dial.