Attaching The Payload To The Stage - Aerotech QNP3 Series Hardware Manual

QNP3 Hardware Manual

2.4. Attaching the Payload to the Stage

Aerotech recommends that customers use a representative payload during start-up to prevent accidental
damage to the stage and the payload. Proceed with the electrical installation and test the motion control
system in accordance with the system documentation. Document all results for future reference. For
information on electrical installation refer to
N O T E : Standard QNP3 stages ship from the factory with no-load parameters (so that the stage will be
stable if it is started up with no payload). How to tune your stage with a payload is described in the Quick
Start guide supplied with your Aerotech piezo controller.
QNP3 stages are very sensitive to variations in payload when under servo control because of their compact,
lightweight design. It is strongly recommended that stages with feedback be enabled with the servo off and
adjusted according to the "Configuring the Servo Loop for a Piezo Stage" page in the Aerotech controller help
documentation for all new payload configurations (this includes the no load configuration).
The payload must be flat, rigid, and comparable to the stage in quality to maintain optimum performance.
N O T E : For valid system performance, the mounting interface should be flat within 5 µm.
If a QNP3 stage with feedback is mounted in a vertical orientation with a heavy payload, its physical travel
range may shift slightly relative to its feedback range. If this shift is observed, adjust the Absolute Feedback
Offset in software as described in the Aerotech controller documentation.
You should take care to avoid damaging the QNP3 with dynamic forces. The Maximum Acceleration and
Moving Mass specifications listed in
a given load condition. To do this, first calculate the maximum load in the direction of motion, also known as
the push/pull force, using Newton's second law as shown in
Then use this load to determine the maximum loaded acceleration as shown in
The derived Equation 2-3
www.aerotech.com
Mechanical Specifications and Installation
Chapter 3
Table 1-3 can be used to determine the maximum safe acceleration for
Equation 2-1
Equation 2-2
can also be used to directly calculate the maximum loaded acceleration.
Equation 2-3
Chapter 2
and the documentation delivered with the stage.
Equation 2-1.
Equation 2-2.
23