Due to COVID-19, I was not able to come back to campus this semester. I also did not have access to a laser-cutter or 3D printer. As such, I opted to use LEGOs to create my mechanism. One of the major advantages of using LEGOs is the ease-of-use. They are simple to understand and allow for rapid prototyping. Furthermore, pieces can easily be swapped out, making any fine-tuning and adjustments a breeze (provided you have the correct pieces).
L1 = LEGO Beam 15 = 4.7 inches
L2 = LEGO Beam 9 = 2.8 inches
L3 = LEGO Beam 13 = 4.1 inches
L4 = LEGO Bream 5 = 1.6 inches
With regard to dimensioning, I actually tested varying links lengths manually to see which rotated smoothly based upon the pieces I had. I settled upon the dimensions listed above. An image of my preliminary mechanism has been included below. Note that it has been mounted to a holding system so that it can rotate smoothly.