TPT July 2016

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76 JULY 2016
AR T I C L E Advanced Machine & Engineering/AMSAW
by Willy Goellner, chairman and founder – Advanced Machine & Engineering/AMSAW
Effect and prevention of vibration
in carbide sawing
by Willy Goellner, chairman and founder – Advanced Machine & Engineering/AMSAW
Vibration is harmful in any sawing machine, but in high
production saws with hard, and brittle, carbide tipped blades,
it can be absolutely catastrophic.
Reducing vibration is the main focus for machine designers,
because vibration dramatically reduces the effectiveness and
tool life of the saw blade and will increase the overall cost-
per-cut.
When vibration is controlled, however, a carbide tipped saw
blade is the optimum tool for high production sawing, because
carbide can cut much faster than other materials such as high
speed steel.
Machine designers pay close attention to certain vibration
frequencies, because not all vibration frequencies have a
damaging effect.
In this article – which is first of a three-part series – AME
focuses on the damaging effect and prevention of vibration
in carbide sawing.
As part of the team that invented the first billet saw using
carbide tipped circular saw blades and the founder of
the AMSAW machines, my design team has learned
throughout the past 50 years that success in carbide
sawing comes from a solid understanding of four factors:
vibration, resonance, damping and stabilisation.
Each component has an infinite amount of natural frequencies
and each natural frequency comes with a corresponding
mode shape (Figure 1).
If the excitation frequency (caused by the tooth hitting the
material) matches one of the natural frequencies of the saw
blade, the blade will vibrate with the associated vibration
pattern. Only certain modes at lower frequencies have a
damaging effect on sawing.
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Figure 1: Harmonic vibration patterns (modes) of circular plates.
Higher vibration frequencies have little effect and are not a concern
for machine designers
Figure 2 and Figure 3: Typical modes which include node circles and
superimposed node diameters only appear at higher frequencies
and have practically no effect on carbide sawing