Setup & Operation 4. Setting of End Effectors

4.3.2 Inertia Setting

Moment of Inertia and the Inertia Setting

The moment of inertia is defined as “the ratio of the torque applied to a rigid body and its
resistance to motion”. This value is typically referred to as “the moment of inertia”,
“inertia”, or “GD2”. When the Manipulator operates with additional objects (such as an
end effector) attached to the shaft, the moment of inertia of load must be considered.

CAUTION

■ The moment of inertia of the load (weight of the end effector and work piece)

must be 0.05 kgwm2 or less. The G3 series Manipulators are not designed to

work with a moment of inertia exceeding 0.05 kgwm2.

Always set the moment of inertia parameter to the correct moment of inertia.

Setting a value that is smaller than the actual moment of inertia may cause

errors, excessive shock, insufficient function of the Manipulator, and/or shorten

the life cycle of parts/mechanisms.

The acceptable moment of inertia of load for a G3 series Manipulator is 0.005 kgwm2 at the
default rating and 0.05 kgwm2 at the maximum. When the moment of inertia of the load
exceeds the rating, change the setting of the moment of inertia parameter of the Inertia
command. After the setting is changed, the maximum acceleration/deceleration speed of
Joint #4 at PTP motion corresponding to the “moment of inertia” value is set
automatically.

Moment of inertia of load on the shaft

The moment of inertia of load (weight of the end effector and work piece) on the shaft can
be set by the “moment of inertia” parameter of the Inertia command.
EPSON
RC+
Enter a value into the [Load inertia:] text box on the [Inertia] panel ([Tools] - [Robo
t
Manager]). (You may also execute the Inertia command from the [Command Window].)

Automatic acceleration/deceleration setting of Joint #4 by Inertia (moment of inertia)

120
100
80
60
40
20
(%) * The percentage in the graph is based
on the acceleration/deceleration at
rated moment of inertia (0.005 kg⋅m2)
as 100%.
100 100
80
50
30
0 0.005 0.01 0.02 0.03 0.04 0.05 (kg･m2) Moment of inertia setting
42 G3 Rev.1