Southbend SB1025, SB1026, SB1024 Adjusting Leadscrew Backlash, Longitudinal Leadscrew Backlash

For Machines Mfg. Since 8/09 S E R V I C E SB1024/SB1025/SB1026

Adjusting Leadscrew Backlash

Leadscrew backlash is the amount of motion the leadscrew rotates before the attached device begins to move.

Although the mill is equipped with double- bronzed longitudinal and cross leadscrew nuts to minimize backlash, leadscrews will always have a certain amount of backlash that will increase with normal wear.

Generally, 0.005"–0.010" leadscrew backlash is acceptable to ensure smooth movement and reduce the risk of premature thread wear. However, if you find it necessary to adjust leadscrew backlash, perform the procedures listed below.

Tools Needed	Qty
T-Handle Hex Wrench 5mm	................................. 1
Hex Wrench 3mm	2
Hex Wrench 8mm	1
Wrench 19mm	1

Longitudinal Leadscrew Backlash

1.DISCONNECT MILL FROM POWER!

2.Loosen the two cap screws on the leadscrew nut accessed from underneath the left side of the table, as shown in Figure 64.

Leadscrew Nut (1 of 2)

& Cap Screw

Figure 64. Longitudinal leadscrew nut and cap screw, as viewed from underneath the left side of the table.

3.Rotate the adjustment plate on the leadscrew nut in small increments, then check the amount of backlash.

4.When you are satisfied with the adjustment, re-tighten the two cap screws.

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