Figure 1: Photo of system

     With parts finally arriving we’ve been able to put system together (figure 1). Since the last blog post we have improved the selection of regulators and were able to reduce the overall length down by 3in; the FSAE car was designed to have all the its' subsystems in a tight package, reducing the profile of our large tank was a priority. 

     We’ve started to go into Milestone 3: Integrate to Car while we wait for the strain gauges to arrive and the validation jig to be fabricated, which is needed to consider Milestone 2: Fabrication and Validation done. This consists of being able to place the components: air tank, piston, solenoid, and electronics into the current car. Choosing the proper location to mount the air tank and piston required to follow the following T.6.1.7 ruleset from the FSAE Rule Book, stating:

Cylinder Location - The gas cylinder/tank and the pressure regulator must be:

a. Securely mounted inside the Chassis

b. Located outside of the Cockpit

c. In a position below the height of the Shoulder Belt Mount T.2.6

d. Aligned so the axis of the gas cylinder/tank does not point at the driver

We had limited choices to place the components as we are working with a already fabricated car. With those constraints in mind, we have chosen to mount the air tank on the suspension bridge (figure 2), which does not interfere with any FSAE sub-system and fulfills T.6.1.7. 

              Figure 2: Placement of the HPA tank and piston (circled) in the Master Assembly

    We chose the placement of the air tank and cylinder through CAD. The process began by acquiring 3D models, since we ordered our piston through McMaster they provide STEP files for all their products, which was a direct import of the piston to our Master Assembly. Though with the air tank having no accurate STEP files we were left with two options: create the CAD with measuring tools or to 3D scan the tank and directly import it to the Master Assembly. Our team has a 3D scanner, so we went with the latter (figure 3). There was a slight concern for accuracy, but the scanner is accurate to 0.1mm and the major dimensions were verified once the scan was complete. After we scanned the air tank and verified the dimensions we imported it into the Master Assembly and started to check various location based on rule T.6.1.7 and avoiding interference with other subsystems.

                                              Figure 3: 3D scanning process of our air tank

     The team has finished fabricating the first steering wheel (figure 4). Any continuation of this portion of the project, other than fabrication of validation jig, is currently being held back by shipping times. The steering wheel was machined out of 5052 aluminum and through Fusion 360’s CAM software. The feeds and speeds were provided by Sulzer machinists. 

                                                      Figure 4: Aluminum steering wheel

     As we are coming to a closing of Milestone 2 and going into Milestone 3, our future plan is to start planning the fabrication of mounting brackets for the pneumatic and electronic components. The mounts can not interfere with current subsystems of the car, we are attending Cougar Racing’s weekly integration meetings to ensure we do not run into this issue. Also the steering wheel has been designed to use the current Quick Disconnect couple, as such there is no need to plan this component's integration. 

     Immediate problems we currently foresee are shipping times, since the last blog post we have mentioned about the team changing the bore size of the piston to accommodate the new working pressure being used by the solenoids. McMaster-Carr has reached out to us about the new multi-position piston being on backorder with the new estimated date of delivery to be in late April. This issue was a major roadblock, though after messing with the assembled pneumatic system we came to the conclusion that a multi-position piston was not necessary and a regular double action cylinder would do the job just fine. The reason for the multi-position cylinder being used was due to the assumption that the shifting gear lever on the car did not have enough force to bring the piston back to its “home” positions after the shifter being actuated (figure 5). When we tested the multi-stage piston the shifter had enough force to bring the piston back to its home position without needing to return it to home with our pneumatic system, as such we changed our piston to be a double acting piston, which McMaster-Carr had in stock and was already delivered this past Thursday (3/20/25). Other than that we do not foresee any other issues. 

                                       Figure 5: Shifting gear lever and its directions of motion