Grizzly G9249 owner manual Threading Operation, To cut threads

Threading Operation

To cut threads:

1.Set the compound rest to the appropriate angle for the thread you want to cut. For a Unified National Series (UNF) thread, this is 29º off of vertical to the spindle axis.

2.If the thread dial (Figure 58) is not engaged with the lead screw, use a 5mm hex wrench to loosen the thread dial and rotate it to engage the lead screw, then tighten the dial.

Half-Nut Lever

Thread Dial

Figure 58. Thread dial and half-nut lever.

3.Select the RPM you want to use. A slower RPM will give you more time to react, espe- cially if threading over a short distance or threading up to a shoulder.

4.Examine the thread charts (inch or metric) on Page 41 and set the feed rate as explained on Page 37.

5.Turn ON the spindle to verify settings. Check to see that the lead screw is turning and verify that the carriage moves in the correct direc- tion by engaging the half nut lever shown in

Figure 58.

-40-

6.Once you are confident the settings are cor- rect, disengage the half nut and turn OFF the spindle.

7.Examine the thread dial chart (see Figure 59) to determine which numbers on the thread dial will engage the half nut.

Note: To maintain accuracy and consis- tency, engage the half nut on the same mark on each pass. Failure to start on the same number each time may lead to cutting off the thread made in the previous pass.

INDICATOR TABLE

T.P.I.	SCALE	T.P.I.	SCALE
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Figure 59. Thread dial table.

G9249  12" x 37" Belt Drive Gap Bed Lathe