Corner Balance Scales

My first engineering project as a new member of the Longhorn Racing team was updating our old, out of date corner balance scale system with something more modern and user friendly. The previous setup was bulky, not modular, and hard to level on the very uneven garage floor.

The requirements were pretty extensive: make four separate plates (the current ones were large and connected), allow them to nest for storage, add the ability to level on a garage slope (with adjustable leg lengths), include lockable legs, have enough range for our very uneven floor, keep the system lightweight, and finally come up with a solution for the bearing plate that interfaces between the current scales and the car.

Design Concept
The design already called for four individual plates, so my main decision was to give each one its own set of leveling feet. Each plate would be its own “plane” with four points of adjustment, allowing us to level over a large, uneven surface as long as we had enough thread length on the feet. This modular idea solved the portability issue, improved user experience with leveling, and gave us far more flexibility during setup.

Modeling & FEA
I modeled a sheet metal assembly in SolidWorks. Steel made the most sense for project, due to it's strength and ease of welding. After running the model through some FEA simulations, I landed on a sheet metal thickness that handled the load case of the car with an acceptable safety factor and deflection.

This was my first real taste of balancing material properties against cost and manufacturability. Since we were using SendCutSend’s, I iterated through several steel thicknesses across different loading conditions to find the sweet spot: strong enough with minimal deflection, but relatively inexpensive and lightweight.

Leveling Foot Decisions
I spent a lot of time choosing the leveling feet and associated hardware. After a lot of browsing through McMaster, I settled on self leveling feet threaded onto bolts through some large nuts welded onto each corner of the plates (great opportunity to use my old welding skills).

I had to think carefully about adjustment range, and making sure there was enough clearance to actually get a wrench or socket onto the bolts. The garage floor is very uneven, so achieving both range and ease of use took more planning than expected.

Manufacturing & Welding
After all the planning and simulation, it was time to order. SendCutSend makes it unbelievably easy to upload a file and get bent sheet metal parts shipped quickly. I was really excited to finally see the plates in person after staring at them on my computer for days. 

Once they arrived, I got to work welding the hardware. I used MIG since it’s super straightforward and great for filling gaps around the nuts. It was fun showing a few other members of the manufacturing team how to run a MIG. After some paint, the plates looked great. 

Bearing Plates

With the leveling plates done, the next task was making a bearing plate assembly to sit on top of each scale. The requirements here were a bit more vague: allow the wheels to “wiggle” freely for accurate corner balancing and include a way to attach a small line for ride height measuring. Because the requirements were looser, I spent more time researching what makes a good bearing plate and how the system should behave.

The scales originally came with a mock diamond-plate surface, but it screwed off easily and left a lot of room to design something better. Since we already had a SendCutSend order going, I came up with a sheet metal assembly that sandwiches a UHMW plastic sheet inside, giving a low friction surface that allows the wheels to move slightly during weight transfer, achieving that "wiggle" I was looking for in a bearing plate.

This was my first time modeling and manufacturing a sheet metal assembly like this. I learned a lot about clearances, hardware selection, and how sheet metal features affect the final assembly. It was a great introduction to design for manufacturing thinking. After assembling the plates, I attached them to the scales via SCS installed weld studs and got to test the full setup with the car.

This project taught me a ton about CAD modeling in SolidWorks, sheet metal design, FEA, and hardware selection. Seeing the car sitting on something I designed and built, and watching it actually work, was a pretty awesome first engineering project on the team.