In this page, you can find the most recent CAD models of the MAE 156B Simons Array cradle and past models/concepts as the team developed and iterated into the final design. Note: Figures are named from earliest to most recent (bottom to top).
Cradle Assembly: Completed Manufactured Model
Figure 3.7 and Figure 3.8 shows the fully assembled and manufactured cradle. The Simons Array Polar Bear team placed meticulous attention and effort into the machining of the cradle. This was because the dimension of many components were subject to high tolerances in order to ensure that the parts will be able to fit together as expected when fastened together. While this was a challenge due to the scale of the final product compared to the machine's available, the team was able to complete both sides of the cradle, as expected. The final dimensions of the each side of the cradle were: 40"x15"x15" and weighed approximately 45 lbs, resulting in a total of 90 lbs.
Figure 3.7: Fully assembled cradle
Figure 3.8: Assembled Cradle with water bottle for scale
Cradle Design - Final CAD Model
Figure 3.5 depicts the most recent and final CAD of the cradle design for both sides of the receiver. Changes in this iteration include: the addition of the mounting hooks that will be used in the actual assembly, its intermediate mounting plate, and slight changes in the assembly to increase the FOS of the cradle and precision of the FEA simulations. Additional gussets were also added to improve the structural integrity and rigidity of the cradle assembly. In addition, the final cradle design and its analysis takes into account a spreader bar (pictured in Fig. 3.6), that will be used to minimize the angle of lift to reduce the tension force experienced by the mounting points and straps.
Figure 3.5: Final cradle design (both sides)
Figure 3.6: Final cradle design with two spreader bars that will be used to help minimize the angle of lift
Figure 3.3 illustrates the first CAD design and model of the cradle concept on one side of the receiver. Figure 3.4 shows an extended view of how each side of the cradle will be mounted to the I-beam of the receiver. Note that the I-beam is not a part of the design and is an already existing component.
Figure 3.3: One side of cradle design (charcoal grey) mounted to an existing I-beam (light grey)
Figure 3.4: One side of cradle design (charcoal grey) mounted to an existing I-beam and the PB-2B receiver
After considering the limited space in the telescope, the design concept was changed to move the front and back 80/20 bars (4: green) to extend out in the lateral direction, instead of the axial direction (along the I-beam).
Figure 3.2: Second iteration cradle design proposal (not to scale)
Figure 3.1: Cradle Design Proposal (not to scale)
Shown in Figure 3.1 is the team's initial design proposal, considering that the I-beam (1) used to secure the receiver on the telescope can also be used to mount to the cradle.
