Sandvik Coromant Silent tools - How to reduce vibration in metal cutting - Manual (Page 20)

Sandvik Coromant – How to reduce vibration in metal cutting 16
Problem solving
Chip jamming:
• Use the largest possible amount of coolant as this will help to evacuate
the chips from the groove.
• Choose a different geometry to reduce the risk of chip jamming.
Dimension problems (tolerances):
• Choose a Silent tool holder which will reduce the vibration – max over-
hang is 5 x D.
• Choose sharp and positive insert geometry, CoroCut – CM or ground
– GF as it enables a smooth cutting action and minimum deflection from
the workpiece.
• Make sure the tool is positioned at correct centre height. The deviation
from the workpiece should not be greater than +/- 0.1 mm.
• Have the shortest possible overhang for the application to increase the
stiffness of the bar. Max 2 x D for steel bars and max 5 x D for Silent tool
bars. A rule of thumb is never to have a tool overhang larger than 8 x l
a
(insert width).
• Choose the largest possible boring bar diameter, to increase stability.
Vibrations (bad surface finish):
• Adjust the cutting speed (v
c
) as the frequency of vibration can change
and the vibration eventually can disappear.
• Increase the feed slightly as this can reduce the friction created when
grooving and reduce the cutting action. However, this can increase the
deflection (the radial force).
• Choose a thinner insert width and make several cuts, especially for the
finishing cut.
• Check the clamping of the boring bar.