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Center Drilling A Workpiece - OTMT SC4 User Manual And Installation Manual

Bench lathe
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7. Set the rotational speed to about 600 RPM.
Move your hands clear of the cross-feed
handwheel as it will rotate under power in the
next step.
8. Use the compound feed to advance the tip
of the cutting tool 10 divisions. This will set
a cutting depth of 0.005" (5 thousandths)
for the facing cut. The compound is used
here to set the depth of cut because the
carriage is locked to the ways.
9. Push the handle of the X-Y Auto Feed
Lever to the left, then rotate it upwards to
engage the power cross-feed. You should
observe that the cross-feed handle is
rotating clockwise and that the cross-slide
is moving slowly away from the operator
with the cutting tool making a facing cut on
the end of the workpiece
10. After the tip of the cutting tool crosses the
center of the workpiece face, push the
handle of the X-Y Auto Feed Lever to the
left, then rotate it downwards to the center
("0") position to disengage the power cross-
11. Rotate the cross-slide handwheel manually
counterclockwise to move the cross-slide
back approximately to its starting position,
clear of the workpiece.
12. Repeat steps 8-11 a few times until you are
completely comfortable with the procedure
for using the power cross-feed.
13. Move the carriage well away from the end
of the workpiece and use a file to clean up
the sharp edge of the face.
14. Press the red Stop button.
15. Use a hex key to unlock the carriage lock.
The cross-slide also can be withdrawn under
power feed by reversing the rotational direction
of the spindle by pressing the Reverse button
) on the control panel after completing the
inward cut. That feature is convenient when
facing a relatively large diameter workpiece of
4" or more.
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Center Drilling a Workpiece

Drilling into the end of a workpiece is another
very common lathe operation. It is good
practice always to make a shallow conical
starter hole using a center drill before drilling
with a regular drill bit.
Drilling into the end (face) of a workpiece
nearly always is preceded by a facing
operation to prepare a flat surface, square to
the length of the workpiece in which to drill.
Complete the facing operation described in the
previous section before beginning the following
Center Drilling a workpiece
For maximum accuracy, it is good practice to
extend the tailstock ram only as far as needed
for the depth of the drilled hole.
1. If it is not already in place, mount the
tailstock drill chuck into the tailstock.
2. Mount a center drill in the tailstock chuck.
Twist the drill slowly while tightening the
chuck jaws to ensure that the drill bit seats
evenly between all three jaws, then tighten
the jaws firmly.
3. Move the carriage as needed to make
room to slide the tailstock up close to the
4. Use the cross-slide handwheel to withdraw
the cross-slide back away from the work
area to make room for drilling.
5. Loosen the tailstock locking cam-lock lever
headstock until the tip of the center drill is