10.6 Conclusions & Future Work

Project Outcomes

Our final project met most of our initial objectives. The mechanism achieves smooth, controlled vertical motion capable of lifting a considerable load. During our demonstration, we showcased this motion by lifting a metal Yeti cup and a smaller object, as shown in the Figure below. Our mechanism was able to raise the object in the vertical direction while maintaining a near-vertical trajectory and ensuring stability.

However, we encountered a mechanical flaw that limited full actuation under load: slippage between the large spur gear and the axle. Although the gear was designed for a press fit and strengthened with adhesive, under high torque demands, the connection continually slipped. This prevented the mechanism from lifting the load vertically under motor actuation alone. To demonstrate motor functionality, we placed the mechanism horizontally, significantly reducing the load from gravity. Under these conditions, smooth powered motion was achieved, as shown in the Video.

Despite this setback, the electronics system—motor driver, motor control, and code implementation—functioned as intended, producing the correct motion profiles.

Lessons Learned

One of the most important lessons we learned was that mechanical coupling is critical. Even small inaccuracies in the fit between key components, such as gears and axles, can lead to major performance issues when the system is under load. We found that relying on press fits and glue alone was insufficient for reliable torque transmission. Additionally, we learned the importance of testing early and testing under real conditions. Early testing with lightly loaded systems can mask critical problems that only appear when the system operates at full load or in the intended vertical orientation. Finally, this experience reinforced the value of iterative and rapid prototyping. Allocating more time for mechanical iterations would have allowed us to find and implement a stronger connection, such as a keyed shaft, before final testing and demonstration.

Future Work

For future improvements, one major upgrade would be the integration of a keyed shaft and corresponding keyway in the gear. A key would prevent rotational slippage by mechanically locking the shaft and gear together, ensuring reliable torque transmission. Alternatively, a D-shaped shaft paired with a matching bore could serve the same purpose, as the motor shaft operates. Another improvement would be upgrading the gear material; using a metal spur gear instead of a plastic one would better withstand the stresses encountered during lifting and reduce the risk of deformation. Additionally, vertical load testing should be performed earlier in the project timeline to identify any weaknesses in mechanical transmission under realistic operating conditions. Lastly, while our system remained largely stable during operation, we observed minor frame flexing. Reinforcing the frame structure would help further enhance payload stability and improve overall system robustness.

Tips for Future Groups

For future groups, we recommend prototyping mechanical interfaces early in the project by thoroughly validating connections between power transmission components. Taking the time to ensure secure, reliable fits at the beginning can prevent major issues later on. It is also important to expect and plan for failures; integrated system tests often reveal mechanical or electrical problems that were not obvious in isolated component tests, so building extra time into the schedule for troubleshooting is crucial. Future teams should also make full use of available resources. Machine shops, 3D printers, and TIW staff can be extremely helpful in solving unexpected mechanical challenges, and seeking machining assistance early is often more effective than trying to patch a design later. Further, there are often much greater wait times later in the semester when trying to use machines and resources at TIW, which can be frustrating and detrimental to even the most prepared teams. Lastly, careful documentation and labeling of electronics, including wiring and code, can save significant time and reduce confusion during debugging, especially when working under tight deadlines.