In Fall 2025, I enrolled in an Intuitive/Counterintuitive Mechanisms Class. This class not only taught theory with inverse kinematics, degrees of freedom, and historical mechanisms, but was also hands-on. My grade was dependent on me designing and building mechanisms for projects.

Since I was already working on my single element Camaro wing, I decided to iterate off of that for my final mechanisms project. I attempted to model a Drag Reduction System (DRS) used to reduce drag and increase straight-line speed through active aerodynamics. The requirement for this project, however, that proved most painful was that the mechanism needed to be spatial. The wing from side-view was truly just a planar mechanism (though cantilevered). So, I need to figure out out-of-plane-actuation.

I chose to use bevel gearing for a servo pinion to drive the arm that raises the second element flap.

By simplifying the model to two 4-bar linkages, I was able to figure out the input-output relation from the actuator to the flap opening. I then used MATLAB Simulink to model the actuation and output from my SolidWorks model. I simplified it as the pinion mating gave me a lot of trouble, and the pinion bevel simply gave a 1:2 ratio to the input I was using in MATLAB.

After 3D printing the model (all tolerances I used actually worked first try), this was the assembled result below. Because the mounting was PLA-CF, I did adjust the tolerance for the larger nozzle size I used on my printer, but otherwise the PLA parts behaved as my previous PLA prints have.

Though this oversimplified example ignores operation under high aerodynamic loads and is obviously not the solution I would use in my actual wing, I did learn and gain experience with actuation. I not only had to spec for the torque required, but the friction in the system itself was also a huge factor alongside gear alignment. I would also use some form of stopping device in the endplates to fix the “closed” position of the flap without relying on the servo holding the load. Below is the video of it in action.