Grizzly G9249 owner manual Adjusting Half-Nut, To adjust the half-nut guide bar

Adjusting Half-Nut

The half-nut should engage the leadscrew firmly without tilting from side-to-side during operation. With normal wear over an extended period of use of the half-nut, adjustment of the half-nut guide bar may be necessary.

The goal of adjusting the half-nut guide bar is remove excessive play so that the half-nut eas- ily and firmly engages the leadscrew, but will not tilt from side-to-side when the carriage is moved back and forth.

Tools Needed	Qty
Hex Wrench 3mm	1
Hex Wrench 5mm	1
To adjust the half-nut guide bar:

1.DISCONNECT LATHE FROM POWER!

2.Unscrew the cap screw shown in Figure 107 and remove the thread dial assembly.

Half-Nut Lever

Cap Screw

Thread Dial

Assembly

Figure 107. Thread dial and cap screw.

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3.Loosen the two set screws shown in Figure 108 one full turn.

Set
Screws	Half-Nut

Figure 108. Half-nut guide bar set screws.

4.Use the half-nut lever to engage the half-nut with the leadscrew, then rotate the carriage handwheel back and forth.

Note: During this step, observe how the half- nut tilts from side-to-side on the leadscrew.

5.Evenly tighten the set screws until a slight resistance is felt.

6.Repeat Steps 4–5until the set screws are just snug—DO NOT overtighten them.

7.Re-install the thread dial.

G9249  12" x 37" Belt Drive Gap Bed Lathe