04/09/07

 Figure 1: Initial Design Sketch (side view)

                                                                                 Figure 2: Initial Design Sketch (side/top view)

Figure 1 and 2 above shows the initial concept of the design.  The concept behind this design is like a carriage rolling inside a circular track, driven by gears.  Two such gear sets are necessary for this, one for the pitch, and the second for the roll.

Pros

Cons

Due to the specifications given, this project was divided into two different tasks.  The first task focuses on the isolation of any vibrations that may occur during the use of the VCCT.  The second task focuses on the easy and accurate micro-adjustment of the projector.

Task 1: Vibration Isolation

The function of a vibration isolator is to reduce the magnitude of force transmitted from a vibratory foundation to a machine.  To isolate the adequate frequency range, the micro-adjustable stabilizer mount will be constructed to act as a hanging spring mass damper system as shown in Figure 3, eliminating almost all movement in the Z-direction.  The goal is to design a system for vibration frequencies that occurs most often during 2-second intervals of use, since the MK-19's are not fired constantly.

For this system, the mount will be built with a series of interchangeable silicone filled springs that act as a spring and a damper.  This can be seen in Figure 4.

Figure 3: Hanging Spring mass damper system.

 Click Here for more on Vibration                                                                                   Figure 4

Click Here for Vibration Calculations                                                                                             

Task 2: Micro-Adjustment

Three spur gear sets will be used to adjust the three DOF mechanisms, the yaw, roll, and pitch.  Analysis of the gear sets was executed and considered to be suitable for the design.  The factors of safety for tooth breakage was determined to be app. 8.9 for the pinion and 6.7 for the gear.  For pitting, the factors of safety for the pinion and gear were calculated as 1.8 and 1.2, respectively.

Click here for calculations and supporting data.