Die & Mould Making - CNC - Computer Numerical Control

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But, there will be a big contact length
when the cutter hits the wall, with risk for
vibration, deflection or even tool breakage
if the feed speed does not decelerate fast
enough. There is also a risk of pulling out
the cutter from the holder due to the
direction of the cutting forces.
The most critical area when using ball nose
end mills is the centre portion. Here the
cutting speed is zero, which is very disadvantageous
for the cutting process. Chip
evacuation in the centre is also more critical
due to the small space at the chisel
edge. Avoid using the centre portion of a
ball nose end mill as much as possible. Tilt
the spindle or the workpiece 10 to 15
degrees to get ideal cutting conditions.
Sometimes this also gives the possibility to
use shorter (and other type of) tools.