1. The coin-flipping decision-making machine
This week, the whole CBA section is building a machine together. After many many brainstorming sessions and discussions, we decided to make this coin-flipping decision-making machine that will help you make one decision from a list of options based on coin-flipping results. I joined the MechE team, responsible for designing and making the physical components. Personally, I designed and printed the camera mount on top of the coin flipper, and helped Cyrus a bit on the solenoid holder and coin flipper funnel design and printing as well. The camera mount works fine first try, as it is very straightforward, just needed to CAD something to adapt from 1/4-20 screws to M5 screws that we’re using for the extrusions. I remembered what Jonny told me about fillet and reducing stress concentration point, and added that in the design. It’s not heavy-lifting, but it’s holding the camera in place.
The humble camera mount
There are many iterations on the coin flipper funnel/cone & solenoid holder as we adjusted the placement of the whole thing and also changed the solenoid to a bigger one. Cyrus made the original design, and he was CADing it on his laptop while I give some advice here and there, and we learned how to CAD better with Fusion together. I do think I am much more confident in Fusion after these few weeks, starting from knowing nothing about it to thinking that I can CAD most of the not too complicated things. We printed the first one with translucent PLA on the Prusa MK4, and also with black PLA on the Bambu Lab printer, and the black one turns out nicer. Black background also made the color detection code more accurate.
Iterations of the cones The coin fipper
In addition to the few 3D printed parts that I contributed, I also suggested during one of the brainstorming sessions that rather than enclosing the coin in the coin flipper, we should allow the user to insert the coin to this machine and ask for its help. This can be a fun and intuitive user interface and marks the start of the machine-using experiecne. Many people (ex. Jonny, Jessica & Cyrus) agreed, but in the end we seem to ignore the “inserting into a coin slot” idea. The “putting in the coin to machine” idea is kept though. I still think it would be fun if this is built like a vending machine of some sort, asking for coins and charging you for each decision it is making. To just deliver a working machine though, this is not necessary, and since we are using a 3d printed coin to reduce weight and simplify head/tail recognition, it is even less important to be able to insert real coins in now.