Southbend SB1014F specifications Backlash Adjustment, Compound Leadscrew, Cross Slide Leadscrew

For Machines Mfg. Since 7/09 S E R V I C E EVS Toolroom Lathes

Backlash Adjustment

Backlash is the amount of free play felt while switching rotation directions with the handwheel. This can be adjusted on the compound and cross slide leadscrews.

Reducing backlash to less than 0.001" is impractical. Avoid the temptation to overtighten the backlash set screw while adjusting. Overtightening leads to accelerated wear of the wedge, nut, and leadscrew.

Compound Leadscrew
Tools Needed:	Qty
Hex Wrench 3mm	1

Backlash is adjusted by tightening the set screws shown in Figure 125. When these screws are adjusted against the leadscrew nut, they offset part of the nut to remove play between the nut and leadscrew.

If you end up adjusting the nut too tight, loosen the set screws, tap the compound a few times with a rubber or wooden mallet, and turn the handle slowly back and forth until it moves freely.

To readjust the backlash, rock the handle back and forth, and tighten the screws slowly until the backlash is at approximately 0.001" as indicated on the handwheel dial.

Set Screws

Figure 125. Compound slide backlash adjustment set

screws.

Cross Slide Leadscrew
Tools Needed:	Qty
Hex Wrench 3mm	1
Hex Wrench 5mm	1

Backlash is adjusted by loosening all four cap screws shown in Figure 126, and then tightening the center set screw, which pushes down on a wedge and forces the nut apart, taking up lash in the nut and leadscrew.

If you end up adjusting the nut too tight, loosen the set screw, tap the cross slide a few times with a rubber or wooden mallet, and turn the handle slowly back-and-forth, until the handle turns freely.

To re-adjust the backlash, rock the handle back and forth and tighten the set screw slowly until the backlash is at approximately 0.001" as indicated on the handwheel dial.

Cap Screw

Set

Screw

Figure 126. Cross slide backlash adjustment screws.

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