Use a ruler or a thread pitch gage to verify that
the grooves are spaced 20 per inch. If they are
not, recheck and correct the gear setup.
Caution: Thread cutting should always be
performed at the lowest speed setting (100
RPM). One way to ensure that the speed is at
the lowest setting is to press the Emergency
Stop button, then rotate it clockwise ¼ turn to
reset it. The spindle speed will be reset to 100
Warning: In the next steps the carriage will
move rapidly towards the headstock. Keep a
finger poised over the red Stop button and be
prepared to stop the lathe quickly as the
carriage approaches the rotating chuck.
The following steps cut the thread in multiple
passes until the correct thread depth is
reached. This exercise assumes that the tip of
the cutting tool is zeroed to the side of the
workpiece from the previous exercise.
1. Press the Reverse button (
2. Press the Start button
3. The carriage should move to the right
towards the tailstock
4. When the tip of the cutting tool is just
past the end of the workpiece, press
the Stop button.
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The carriage is now positioned to begin cutting
Note: the following sequence of steps must be
followed carefully to cut a good thread. The
power-feed (half-nut) lever stays engaged
through the whole procedure. If is disengaged
at any time, alignment of the thread may be
lost on subsequent passes, creating a poor
Note: After two or three passes, as the thread
becomes deeper, the depth of the cut must be
reduced, advancing the compound only 3, 2 or
1 divisions rather than 5.
1. Advance the compound handwheel by 5
divisions to set the depth of the cut.
2. Press the Forward button (
the digital display indicates FOR.
3. Press the Start button; keep your hand
near the Stop button
4. Allow the cutting tool to cut about 1" down
the length of the workpiece.
5. Press the Stop button
6. Rotate the cross-slide handle one full turn
counter-clockwise so that the handle is at
the bottom of its swing.
7. Press the Reverse button (
8. When the tip of the cutting tool clears the
end of the workpiece, press the Stop
9. Rotate the cross-slide handle one full turn
clockwise so that the handle is at the
bottom of its swing and the dial is at "0".
10. Repeat steps 1-10 three more times. Each
pass deepens the thread. As the thread
becomes deeper, advance the compound
by smaller amounts.
compound dial reaches a reading of
). Verify that
). Press the
Continue until the