PFR - Aerospace Engineering Sciences Senior Design Projects ...

Project Final Report – CUDBF April 30 th , 2009
ASEN 4028: Aerospace Senior Projects
from the insertion of the rocket and restrain itself automatically. In order to release two stores
from one servo, it was determined that one servo would control two pins by string. This would
allow the servo to retract one pin which is experiencing the tension but the other pin would
remain stationary since no load is applied through compression. The servo actuator would need
to produce a torque equal to the spring constant times the gap width multiplied by the length of
the servo arm. A concept of this can be observed in Figure 17.
Figure 17: Preliminary Drawing of Tab-Spring Payload System
5.2.1.3 Sliding Trigger Design
The sliding trigger design is based off of the coordinated movement of two pins to load and
release the store. A tab with a hole is rigidly fixed to the store. To secure the store to the
aircraft, this store-fixed tab is inserted into the bottom of the aircraft. As it slides in, it pushes
against the rotating pin arm (seen in the figure below) which in turn rotates the release pin.
Further insertion causes the rotating pin to rotate until it is perpendicular to the vertical store tab.
At this moment, a spring will force the release pin back into its original position. This will
prevent the rotating pin from coming back to its original position and the store will remain
secured to the underside of the aircraft. To release the store, a servo actuator pulls the release pin
out of its locked position and the weight of the store causes the rotating pin to rotate to its
original position and release the store. A concept of this option can be seen in Figure 18.
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