Week 9

Week 9
The raw materials that we were waiting on as well as the fasteners came in this week so we were able to machine the remaining parts in order to start the assembly. Figures one and two show group members working on the assembly in the Formula SAE room. During the week the chassis was drilled in order to mount the pedal box into the car. By the end of the week the pedal box was all put together. Figure three shows the complete final assembly of the pedal box.

Fig 1:  Group members working on the assembly 

Fig 2:  Group marking holes using a transfer punch

Fig 3:  Final assembly

Week 8

Week 8

The machined parts that were ordered came in this week (Figure 1) however, the remaining parts did not. There was a power outage at Drexel and because of this it set back the shipment an entire week. As seen in figures two and three, the parts fit perfectly in the chassis. The parts that did not arrive include raw materials that need to be machined by the team and some fasteners that are required for assembling the pedal box.

Fig 1:  Machined parts

Fig 2:  Close up view of main structure of pedal box resting in the chassis

Fig 3:  Distant view of main structure of pedal box in the chassis 

Week 7

Week 7
After Dr. Tan's approval the group placed the order for the complex machine parts as well as the rest of the materials that will be needed for the pedal box. The group also finished the final draft of the final report which is due this week. Putting together a presentation on the final design is the next step for the team members.

Week 6

Week 6
With the new design, the group had to do finite element analysis on each part to verify that the entire assembly will be able to withstand a 450-pound force on the break pedal. Figure 1 shows a part of finite element analysis on the main structure of the pedal box. After completing the finite element analysis, the group showed the design to Dr. Tan to make sure the parts could be ordered. Once receiving the approval, the next step was to start a rough draft of the final report which will be due next week.

Figure 1:  Finite Element Analysis Factor of Safety Plot 

Week 5

Week 5

This week we had to redesign the majority of the pedal box due to the placement of the steering rack and pinion being overlooked and partially due to the team’s inexperience with Formula SAE racecars. When doing the redesign, as seen in Figure 1, the team had to go back to the drawing board and take new measurements. After doing so the next step was to create another pedal box with nearly all new sized pieces. The main structure will be machined from a 0.625” thick plate of 6061-T6 aluminum that is 8” wide by 13.25” long. All of the other pieces will also be constructed out of the same material as the main structure. The total calculated weight is said to be 5.95 pounds which is a 2.84-pound savings from the previous design. In the end this redesign set the group back approximately a week.

Figure 1:  Redesign Pedal Assembly 

Week 4

Week 4

During week 4, the team designed the Pedal Box in Solidworks.  The entire assembly will be made from various thicknesses of 6061-T6 Aluminum.  This material was chosen for its strength to weight ratio.  A few members performed a Finite Element Analysis of each part using Solidworks' built in features.  As stated in the Formula SAE rulebook, the brake pedal assembly must be able to withstand an applied force of 450 lbs. Every part had a safety factor above 1.5, which was the minimum value expected by the advisors.  The maximum displacement under that maximum load was 0.0328" which is well under the maximum values stated in the FSAE rules of 0.125".  Solidworks calculated the total mass of the assembly to be 8.79lbs.   

Figure 1: Isometric Front View With False Floor Shown

Figure 2: Isometric Rear View With False Floor Hidden

Week 3

Week 3
To start off week 3, the group sat down together and learned Solidworks, a 3D modeling program, in which the group had no prior knowledge with. Learning the new program brought some challenges to the group but before the end of the week the group had a decent understanding of how the program worked. After learning Solidworks, members redesigned and improved drawings by taking them from Inventor and redesigning them in Solidworks. During the meeting with Dr. Tan, the group showed him drawings and received a suggestion. That suggestion was to begin finite element analysis of each part to assist in the removal of weight by ensuring that the overall structural integrity of the part will not be harmed.  

Week 2

Week 2
For the second week, the group continued their research by evaluating off-the-shelf assemblies for full-size racecars (shown below in Figure 1). Brainstorming for different ideas and concepts to make the pedal box as cheap as possible while having it still be durable and lightweight was also done this week. After this week's meeting with Dr. Tan, the group was able to establish the overall design for the final pedal box. The design entailed an underfoot master cylinder location with a false floor covering the assemblies below. As for the brake pedal, it has a mechanical advantage of three to one. After creating a final design, the group of four created the discussed design in Inventor to show Dr. Tan the following week (shown below in Figure 2).

Figure 1: Tilton Racing 600 Series Underfoot Pedal Assembly 

Figure 2: Initial Inventor Drawing of Pedal Assembly

Week 1

Week 1
In the first week of the pedal box project the group defined the constraints and began research. Before defining the constraints, the group met with the current president of the Formula SAE club, Rob Gibbons. At the meeting, they took measurements of the pre-existing chassis in order to plan for the next weeks. Also defined was the style of brake master cylinders that will be used as well as their mounting style. Research in the first week consisted of looking up other teams and communicating with them in order to gain knowledge. The 2016 rulebook was also read through to find all of the rules pertaining to the pedal box.

Tilton 77 Series Master Cylinder