First factor to take into consideration are the dimensions of the servo. Since we already have the STL files to 3D print our Fuzzy Bear, screwing in the servos with the right dimensions would be at ease compared to the larger servos that would require resizing the STL files in Solidworks. Therefore selecting the servos with the perfection dimensions would be much more time efficient. The second factor to take into consideration is the strength and speed of the servo. Our fuzzy friend will be carrying a 3dot microcontroller, a servo shield, a thermal shield, and most importantly, an external battery pack. All of this weight does add up which is why we wanted the minimum torque requirements to be at a minimum of 2.0 kg/cm. The time it takes for the servo to reach its desired position is also taken in consideration. Quadruped robots normally face balancing issues which makes it essential for the servo to catch itself on time to prevent itself from falling over. Last of all, price is also a deciding factor for this project. Cost is a constraint every project must face which is why we needed to keep the price low while taking all these other factors into consideration.

The decision narrows down to three servos that are listed in the table above which are the SG90s, the MG90s, and the LFD-01Ms. For the other two, they were quite strong but were simply just too heavy and expensive. The LFD-01Ms are the right dimensions and do include an anti blocking system but this seems unnecessary if Fuzzy Bear is calibrated to avoid jamming its legs together. The price would be over double of the MG90s and is also on the weaker side therefore it wouldn’t be certain it would be able to lift its own weight up. The same situation goes for the SG90s where it is cheap but doesn’t provide enough strength.