Southbend SB1049F owner manual Apron Threading Controls, Thread Dial, Feed Control Lever

	O P E R A T I O N
For Machines Mfg. Since 5/11		13" Heavy 13® Gearhead Lathe

Apron Threading Controls

The half nut lever engages the carriage with the leadscrew which moves the carriage and cutting tool, along the length of the workpiece for threading operations (see Figure 77).

Important: Make sure the feed selection lever is in the disengaged (middle) position before attempting to engage the half nut.

Half Nut

Feed ControlLever Lever

Thread Dial

The numbers on the thread dial are used with the thread dial chart to show when to engage the half nut during inch threading. The thread dial gear must be engaged with the leadscrew for this to work. Loosen the knurled knob on the thread dial, pivot the dial gear toward the leadscrew

so that it properly meshes with the leadscrew threads, then re-tighten the knob, as shown Figure 78.

Leadscrew

Dial Gear

Knurled

Knob

Cross Slide

Disengaged

Carriage

Feed Control

Lever

Disengaged

Halfnut

Lever

Engaged

Figure 78. Thread dial engaged with the leadscrew.

When threading, we recommend using the slowest speed possible and avoiding deep cuts, so you are able to disengage the half nut when required and prevent an apron crash!

Figure 77. Apron threading controls.

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