Page 12 - ISCAR_WORLD_2021

Barrel Cutter

Shapes a New When compared with a common taper endmill, the

taper barrel provides theoretically pinpoint contact
Milling Trend between the major cutting edge and a machined
surface that decreases accuracy errors and prevents
recutting of a produced shape. The taper shape also
contributes to reducing tool overhang – an important
factor for improving tool performance.
Barrel and oval endmills are mainly utilized for cutting
side surfaces. If machining a complex bottom surface
Endmills featuring a cutting edge that is
actually the segment of a large-diameter arc is needed, a lens-shape endmill offers a good
were introduced approximately 25 years ago. solution. This tool features barrel cutting edges on its
As the cutting-edge shape of these endmills end surface to ensure milling with a large stepover.
is reminiscent of a barrel profile, terms such
as "barrel milling cutters", "barrel endmills"
or, in shop talk, often simply "barrels" soon
became common when referring to these
types of endmill.

At first, the use of these barrel-shape mills was
limited more or less to a few specific applications,
such as machining 3D surfaces of complex dies and
turbomachinery components. However, advances
in 5-axis machining and in CAM systems have
significantly expanded the boundaries of barrel
endmill applications.
Traditionally, ball-nose and toroidal cutters
perform these machining operations. However,
the large-diameter arc of the endmill cutting
edge results in a substantial reduction of
the cusp height generated between passes The barrel endmills - classical barrel-, oval- and lens-
machined by a ball-nose or toroidal cutter. shaped cutters - provide efficient tools for machining
Another advantage of this type of cutting 3D surfaces. Nevertheless, for a long time the
edge versus ball-nose and toroidal complexity of CNC programming for applying barrel
cutters is a significant increase in the endmills was a constraining factor in actively integrating
distance between passes (a stepover these promising tools into the appropriate branches
or a stepdown, depending on the of the metalworking industry. The growing use of
direction of a cutter displacement 5-axis machine tools and the latest progress in CAM
after every pass) - at least five times and, subsequently, machining time can be software has changed the situation dramatically, and
more without degradation of the noticeably reduced. Increasing the distance today we see intensive utilization of barrel endmills in
surface finish parameters! This between passes also improves tool life and, manufacturing various parts with geometrically complex
means that the number of passes therefore, diminishes tool cost per part. surfaces. The main consumers of these "cutting
barrels" are producers of aerospace, die and mold,
medicine, turbine and compressor components.

DUSTRY 4.0
12 MACHINING IN TELLIGENTLY ISCAR 13