**Written by: Trevor Bendik**
**Note:** This document is NOT intended to be machining training, this document serves as a collection of decisions, processes, and steps that were taken to achieve a final product.
The design process heavily considered manufacturing, such that custom components could be made using 3-axis CNC milling in as few setups as possible. The brake pedal design used 3 custom aluminum components, the **Pedal**, **Mount**, and **Rail** Fig. 1-2. This page will be split into three major sections by component, respectively.  **Fig. 1.** *2025-2026 Brake pedal design and exploded view with labeled components* [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/asdasdasd.jpg) **Fig. 2.** *2025-2026 Brake pedal custom aluminum components* #### **Pedal*****Material***: 7075-T651 \[*Note: T651 is NOT the same as T6, they have different mechanical properties*\]
Based on geometry, the part needed a minimum of three setups using 3-axis CNC milling: OP10 (top side), OP20 (bottom side), and OP30 (pedal pad holes). OP20 (bottom side) required custom 'soft-jaws' due to not having 2 parallel flat surfaces for adequate workpiece clamping and positioning. OP30 (pedal pad holes) also required soft jaws to ensure that the pedal pad interface was perpendicular to the drill. ##### OP10 The goal of the first operation is to machine as much as possible. For that reason, a stock block was chosen such that the entire pedal outer counter and the top half of internal webbing could be machined in one go, while leaving adequate clamping area, and at least 0.100" of clearance between the machining bottom height and the top of the vise jaws.**Stock Dimensions:** 10.90" X 3.60" X 1.36" \[Fig. 3\]
[](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/screenshot-2026-03-28-at-4-01-38-pm.png) **Fig. 3.** Autodesk Fusion stock-workpiece OP10 set up The origin for the CAM program is set to 'Top Center of Block' for easy work offset probing and to ensure the machined features are centered on the workpiece. The model is centered in the X and Y directions, and is offset by 0.100" from top in the Z direction. This was done to enable facing passes. The list of OP10 tooling sequences, 1.1 - 1.17 can be seen in Fig. 4. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/C13screenshot-2026-03-28-at-1-25-34-pm.png) **Fig. 4.** Autodesk Fusion CAM program OP10 Sequence 1.2 and 1.3 have a bottom height of 0.200" below the model. This is to ensure that the contour is milled completely in one pass so there are no subsequent offset issues when it comes to the outer contour. Sequence 1.4 is a drill that passes through the bias-bar bore to be used as a 'machined' surface for probing in OP20. Note that the bias-bar bore is not machined in OP10. That is intentional to maintain workpiece rigidity for clamping in OP20. The bore will get machined in OP20. Note that only 7 tools were used, 1/2", 1/4", 1/8" ZrN coated carbide flat end mills, 0.323" and 0.257" HSS drills, and a 1/4" carbide chamfer end mill. The completed OP10 product can be seen in Fig. 5. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/image-28.jpeg) **Fig. 5.** Completed Pedal OP10 A problem was encountered with the 1.17 chamfering sequence. The program was written to use a 1/4" chamfer mill, but someone had replaced my tool with a 3/8" chamfer mill, and the tool was bigger than expected, and it clipped the contour edges of the pedal when it plunged to chamfer the webbing on the inside pocket. ##### OP20 The goal of the second operation is to remove all excess stock, finish the bias-bar bore, and then finish the internal webbing features. First, to do this, a custom soft jaw had to be created, something that secured the workpiece such that the machined features in OP10 were completely face down, and did not add too much compressive stress on the webbing as it was machined out. Additionally, I wanted the webbing to be supported vertically underneath such that chatter/vibrations were minimzed, hence the following soft jaw design \[Fig. 6\]. FIG 6 FIG 6 CAPTION To make these soft jaws, raw rectangular blocks were 3D printed out of black PETG (Fig. 7). Then, the soft jaw features were CNC machined. This was done to ensure tolerances were met, as 3D printers struggle with dimensional accuracy and necessary printing resolution to meet certain features (even if it claims to be good at all of those things). Its important to note, that the coolant was turned off during this machining, and was periodically sprayed using the coolant hose instead (max 2 times per cycle). This prevented the PETG from getting water logged with coolant and swelling. Had the workpiece swelled, the dimensional accuracy would again be impacted as it shrunk post-machining, and it would have caused offset issues in the OP20 machining cycle. The final soft jaw pieces and post-OP10 workpiece can be seen in Fig. 8. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/softjaw.jpg) **Fig. 7.** Soft jaw blocks in progress of printing [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/image-58.jpg) **Fig. 8.** Post-OP10 workpiece and newly machine custom soft jaws. The OP20 program uses 'rest-machining' which directly ports the OP10 final stock shape and allows us to continue machining features (Fig. 9). For the origin, the X and Y in this program are centered on the 0.323" through drill at the bias-bar bore location. The Z is set at the bottom face of the workpiece machined in OP10, this was probed off the surface of the soft-jaws. The list of OP20 tooling sequences, 2.1 - 2.8, can be seen in Fig. 10. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/screenshot-2026-03-29-at-2-31-22-pm.png) **Fig. 9.** Autodesk Fusion OP20 CAM setup [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/screenshot-2026-03-29-at-2-45-17-pm.png) **Fig. 10.** Autodesk Fusion OP20 CAM OP20 used the same tools at OP10, so nothing changed, the final product can be seen in Fig. 11. The program ran flawlessly, there was no measurable offset from OP10 features, and the machine experienced zero chatter. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/image-59.jpg) **Fig. 11.** Completed Pedal OP20 ##### OP30 The goal of the third operation was to drill out two holes for the pedal pad rivets. The brief CAM program can be seen below in Fig. 12. The tooling sequences used a 1/4" carbide chamfer mill and a 0.129" HSS drill. The workpiece was held in this position by taking 1 of the soft jaws used in OP20 and turning it on its side such that the pedal pad plane was parallel with the vise jaws. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/screenshot-2026-03-29-at-3-19-19-pm.png) **Fig. 12.** Autodesk Fusion OP30 CAM The completed piece can be seen below in Fig. 13. FIG13 FIG 13 CAPTION ##### OP40 This operation was not originally part of the manufacturing plan. It was upon assembly that a few issues became apparent. The bias-bar steel sleeve had been press fit into the pedal, and retaining ring slots were needed internally and externally to secure the spherical bearing and the pedal with respect to the sleeve. Therefore, the goal of this operation was to add those slots to the sleeve. The setup for this operation differed significantly, the workpiece was clamped in a circular chuck on the sleeve (Fig. 14). For the origin, the X and Y were centered on the sleeve, and the Z axis was set on the top flat surface of the sleeve. In hindsight, it would have been safer to set the Z at the top surface of the pedal to make sure the slots were milled with respect to where the sleeve was mating with the pedal rather than the center position of the sleeve. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/uInscreenshot-2026-03-29-at-3-37-44-pm.png) **Fig. 14.** Autodesk Fusion OP40 Setup and CAM sequences Due to limitations on tool stick out, and wanting to minimize tool deflection, the program was ran on one side, and then flipped and ran again on the opposing side. The final product can be seen in Fig. 15. [](https://wiki.ufsolargators.org/uploads/images/gallery/2026-03/image-60.jpg) **Fig. 15.** Final Pedal OP40 #### **Mount*****Material***: 7075-T651 \[*Note: T651 is NOT the same as T6, they have different mechanical properties*\]
Based on geometry, and desired finish, this part required 5 major operations, with a 6th operation at the end to create a function clearance for the assembly design. ##### OP10 ##### OP20 ##### OP30 ##### OP40 ##### OP50 ##### OP60 #### **Rail*****Material***: 7075-T651 \[*Note: T651 is NOT the same as T6, they have different mechanical properties*\]
Based on geometry and select choices, the Rail required 5 major operations to complete the as-designed component. Two extra operations were performed at the end to reduce weight of the component. ##### OP10 ##### OP20 ##### OP30 ##### OP40 ##### OP50 ##### OP60 ##### OP70 # Design Justification # Issues