Blog #4 - Design Process Ends, Fabrication begins!

From January 31 to February 14, the suspension team worked on compiling drawings and DSX files to be sent for machining and laser-cutting. However, during this process, some design work had to be modified to make the fabrication easier and less time consuming. The team made the necessary modifications and checked for any kinematic and dynamic changes that may arise from the modifications using OptimumK and OptimumD software. Next, the team started cutting the suspension arm tubes in the FSAE shop, and welded the first A-arms set for the lower rear A-arm (Figure 1). Also, the team compiled and ordered the bearings, rod-ends, and the weld-bungs. These parts are expected to be delivered to the FSAE shop by mid February. In addition, the machinist at the Energy Research Park reviewed the uprights and hubs drawings and will start machining the uprights as soon as the Aluminum 7075 plate arrives. Finally, the team is also making 3D printed uprights and hubs as prototypes to double check for any dysfunctionalities and to avoid having any issues on the machined parts (Figure 2). The team also finalized the damper bridge and performed FEA on it (Figure 3).

Figure 1. A lower rear A-arm is displayed above. Figure 2. The figure shows a 3D printed hub.

The challenges the team currently faces are finalizing the files used to cut the tabs and completing the clearance check with the 3D printed models. Another challenge is making sure that the FEA being performed on the damper bridge is accurate to help ensure the damper bridge is strong enough to take on forces being applied onto it.  More boundary conditions will be implemented in the FEA for the damper bridge. The new analysis would include the tabs connections that would closely resemble the actual bridge positioning.

Figure 3. The FEA on the damper bridge (located in the rear section of the chassis) can be seen. The displacement of the bridge is shown above.

The team’s plan for the upcoming work period between February 14 and February 28 is to complete the manufacturing of the A-arms and finalize the clearance check by using the 3D printed prototypes. The team is also expecting to complete part of the sub-assemblies and work on developing a validation process for the uprights and the hubs. By completing the clearance check and finalizing sub-assemblies, the team will compile the required files to complete the tabs and start welding them on the chassis. After this process is complete, the anti-roll bars and steering rack plate fabrications (Figure 4) will be a part of the upcoming period plan. The team is also required to present the progress report as a part of the capstone requirements during this period.

Figure 4. The steering plate (in blue) is bolted to the chassis. The steering rack (in grey) will be mounted onto the plate to prevent the steering rack housing from moving.