Cutting Techniques - KNOVA KN WL-12M Manual Del Usuario

OPERATION
Spur
center
• Clean the tapered end of spur center and the inside of
the headstock spindle.
• Insert the tapered end of the spur center (with
the attached workpiece) into the headstock spindle.
• Support the workpiece while bring the tailstock into
position. Lock the tailstock to the bed.
• Advance the tailstock quill with the handwheel in order
to seat the live center into the workpiece. Use enough
pressure to secure the workpiece between the centers
so that it won't fly off, but do not use excessive pressure.
• Tighten the quill locking handle.
Attention: The tailstock ram is capable of exerting
excessive pressure against the workpiece and the
headstock. Apply only sufficient force with the
tailstock to hold the workpiece securely in place.
Excessive pressure can overheat center bearings
and damage both workpiece and lathe.
• Move tool rest into position. It should be parallel to
the workpiece, just below the centerline and
approximately 3mm to 6mm from the corners of
the workpiece to be turned. Tighten tool rest base to
lathe bed.
Center
line
• Rotate workpiece by hand to check for proper
clearance.
• Start lathe at lowest speed and bring it up
the appropriate speed for the size of workpiece.
Workpiece
3 -6 mm
Tool rest

3.2 Cutting techniques

Roughing out
• Begin with a large roughing gouge. Place the tool on
the tool rest with the heel of the tool on the surface
to be cut.
• Slowly and gently raise tool handle until cutting edge
comes into contact with the workpiece.
• Beginning about 50mm from the tailstock end of
the workpiece, roll the flute (hollowed- out-portion) of
the tool in the direction of the cut. Make long
sweeping cuts in a continuous motion to rough the piece
down to a cylinder.
• Keep as much of bevel of the tool as possible in contact
with the workpiece to ensure control and avoid catches.
Note: Always cut down-hill, or from large diameter to
small diameter. Always work toward the end of
workpiece, never start cutting at the end.
Direction
of cut
• Once the workpiece is roughed down to cylinder, smooth
it with a large skew. Keep the skew handle perpendicular
to the spindle and use only the center third of the
cutting edge for a long smoothing cut (touching one of
the points of the skew to the spinning workpiece may
cause a catch and ruin the workpiece).
• Add details to the workpiece with skew, parting tool,
scraper or spindle gouge.
Beads
• Make a parting cut for what is to be a bead to the
desired depth. Place the parting tool on the tool rest
and move tool forward to make the full bevel of the tool
come into contact with the workpiece. Gently raise
handle to make cut to the appropriate depth.
• Repeat for other side of the bead.
• Using a small skew or spindle gouge, start in the center
between the two cuts and cut down each side to form
the bead. Roll the tool in direction of cut.
Coves
• Use a spindle gouge. With the flute of the tool at 90
degrees to the workpiece, touch the point of the tool
to the workpiece and roll in towards the bottom of
the cove. Stop at the bottom; attempting to go up
the opposite side ma cause the tool to catch.
First cut
7
Spindle
rotation
Second cut