Manufacturing Machinery World October 2021

ROBOTICS & AUTOMATION
COMPACT AUTOMATED TURNING CELLS WITH
INTEGRATED ROBOT ARM
In a world first, Japanese machine tool
manufacturer Okuma has incorporated a
robotic arm inside its CNC turning centres
for automated production of shaft- and
chuck-type components. All of the
manufacturer's machine tools are sold and
serviced exclusively in the UK and Ireland by
sole agent NCMT (www.ncmt.co.uk).
One of the first Okuma lathes to benefit
from an internal Armroid (Arm Robot
Intelligent Design) workpiece load / unload
system is the LB 3000 EX II, one of which is
available for demonstration in the agent's
Coventry showroom.
Three different end-of-arm effectors are
available for performing different tasks. One
is for blasting air or coolant within the
cutting zone. It can be programmed to follow
the cutting tool for breaking up stringy swarf
or to clean down the whole working area,
greatly improving chip management. A
roller end effector provides support under a
shaft component during cutting to minimise
chatter.
In combination with a workpiece stacker,
the third end effector is a two-finger gripper
for automatically holding shaft-type
workpieces around their circumference for
loading and unloading, weight capacity
being 5 kg. All three end effectors are stored
within the machine and are exchanged
automatically by the robot.
A longer, more powerful Armroid can be
integrated into a second Okuma turning
centre, a Multus B250II multi-tasking lathe.
The robot arm handles workpieces up to 10
kg and possesses a fourth type of end effector
with a 3-jaw gripper for holding billets
around their end faces.
Armroid systems are ideal for high mix,
small batch work. The extended periods of
unattended running free the operator to
carry out duties in other parts of the factory.
The cells are not, however, intended for
lights-out production of large quantities of
the same part due to the limited number of
workpieces that can be accommodated by the
stocker.
While most conventional robotic systems
require complex integration and special
training for staff, Armroid needs neither. As
the robot is part of the machine tool,
expensive system integration is unnecessary.
Using Okuma's own OSP-P300A control, an
operator enters the coordinates for the start
and finish points and the robot moves
through its motions unerringly. Roid Navi
software simplifies programming using
images and on-screen guides.
As the machine and robot operate
seamlessly and always know where each
other are, by enabling the control's built-in
collision avoidance system each cycle is
automatically generated while avoiding
unwanted interference between the moving
elements. In addition to automated running
under program control, manual operation is
possible via a pulse handle that micropositions
the arm.
Okuma has also developed a Standroid
automation solution with the requirements
of small and medium size enterprises in
mind. The compact cell, which contains a
floor-mounted robot, can be placed next to
various Okuma vertical machining centres,
either newly purchased or already in
production on a shop floor.
Currently six Okuma machining centres
may be equipped with this cell. Simply
connecting it to the power supply and a
network cable completes the set-up. Whereas
conventional robotic systems usually require
three days to be integrated, adding a
Standroid can be completed in a day and
there is no need for safety barriers.
Like Armroid, Standroid is easy to
operate by simply defining start and end
points of the robot arm, while the system
automatically calculates movements and
avoids collisions. This greatly reduces set-up
and prove-out times. For maximum
flexibility, it is possible to switch between
automated and manual workpiece loading
and unloading.
In conclusion, these automation solutions
are designed for OEMs and subcontractors
involved in high mix, low volume
production that want to use long periods of
unattended operation to deploy personnel
elsewhere and maximise operational
efficiency. They are not intended for factories
producing large volumes of the same
component or for lights-out running. When
used in suitable applications, the main
advantages are a compact footprint, ease of
use, minimal operator training, machinerobot
compatibility and elimination of the
cost and potential difficulties associated with
integration by a third-party.
www.ncmt.co.uk
Manufacturing Machinery World, October 2021 25