Rockwell Automation LDAT Integrated Linear Thrusters - Manual (Page 48)

48 LDAT-Series Integrated Linear Thrusters
Rockwell Automation Publication LDAT-IN001A-EN-P - August 2012
Setting Travel Limits
Linear thrusters are designed to use the software overtravel limits available in RSLogix 5000 and
Ultraware software.
Overtravel limits should be set according to the maximum speed of the servo drive system and
the payload of the application. The Deceleration Distance before the slide contacts the
end-of-travel bumpers can be determined based on the Deceleration Rate of the load, and the
available peak force from the stage-drive combination. Then use Motion Analyzer software to
calculate the minimum deceleration distance at the maximum speed of your application.
(1)
Software overtravel limits are preferred for these reasons.
• Hard-wired overtravel limit switches are typically located in a position that does not
allow the linear stage to decelerate before mechanical damage occurs.
• Software overtravel limit switches can be precisely set, based on maximum speed and
load inertia. The stage will come to a complete stop before physical damage occurs.
In addition to software overtravel limits, the end of travel bumpers for the linear stage will stop
the carriage up to the ratings listed in the table.
Bumper Stop Energy Limits for Linear Thruster End of Travel
To calculate kinetic energy of the carriage with your payload use the formula:
J = energy in Joules
M = moving mass (linear carriage + payload) [kg]
V = maximum velocity of stage in your application [m/s]
(1)
(1) Velocity and kinetic energy can be much higher due to uncontrolled, worst-case motion that is only constrained by the length of
stroke and the power capacity of the motor-drive pairing.
Cat. No. Energy Limit J (in•lb) Cat. No. Energy Limit J (in•lb)
LDAT-S03xxxx
2.5 (22.48)
LDAT-S10xxxx 8.19 (72.50)
LDAT-S05xxxx LDAT-S15xxxx 19.2 (170.00)
LDAT-S07xxxx
ATTENTION: If energy greater than the bumper capacity is anticipated in the application, you
must provide additional mechanical means for safely stopping the slider.
J
1
2
--- M  V 2 
=
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