Overall, our project went well. We achieved our goal of producing an interactive game that simulated the retro arcade game feel, though we identified several aspects that could benefit from further iterations.

Lessons Learned:

One lesson we learned is that tolerance for 3D prints can vary across machines and filaments. Many of our parts were printed at TIW from PETG, but when we designed mating parts to be printed on personal machines from PLA, the filament would change. We learned that for mechanisms that required tight tolerances, it was much better to print and iterate on the design while keeping the machine and filament consistent.

We also learnt that some wire connections can be looser than they appear and should be secured when finalizing your design so that they do not get disconnected and loose all the time. Simple electrical tape should be good enough to hold them for a demo, as long as they are twisted together properly.

Future Work:

One aspect of our project that we want to improve on is the motion of our character. First, we would like to software-lock the range of motion of the slider crank. Due to the slider crank mechanism, if you held the joystick in one direction, the character would continuously move from side to side, and the joystick direction would flip. Several times during the demonstration, this confused our participants, so this fix could streamline the controls.

Next, as we used a DC motor for our cam-follower jumping mechanism, the Arduino had no awareness of the cam position. This meant that the jumping action did not have a consistent response time and could be stopped in the “Up” configuration, so the character would float above the obstacles on the conveyor belt. If we added an encoder to the jumping cam, we could program the jumping mechanism to stop and begin at the same place, and eliminate any inconsistencies during the jumping action. This would also allow us to make the controls more sensible by switching jumping to be on a button that you could press or hold to jump the correct number of times.

Tips for Future Groups:

One thing that benefited our project was 3D printing as early as possible. It is extremely easy to get stuck in “CAD Goggles,” where you have no sense of scale, and it's hard to grasp how mechanisms will function in the real world. 3D printing early allowed us to catch many early-stage design errors, such as tolerance, fitment, and function, early, before large amounts of time were spent on designs.

Another thing that benefited us was developing a fully constrained SolidWorks assembly. Having a “Digital Twin” of our model allowed for new parts to be designed in the context of all of our existing parts, and helped eliminate collisions and fitment issues between our subassemblies.

Acknowledgements:

Thank you to TIW faculty and Scott Evans for support on project materials and suggested design improvements.