Lots of specific answers here and on the other thread, so I’ll give a more general formula for how to go about this sort of mechanism design:
- Start with basic requirements
a. How many gampieces have to be held at once?
b. Where can/should they be held at?
c. Do you need to eject? sequence?
d. Where do they need to enter the conveyor, where do they need to leave?
- Design some basics
a. Namely, pick a path, dimensions, and mounting points to transfer the gampiece along that path.
- Split the mechanism up. Add the right number of “degrees of freedom” to achieve the gamepiece motion desired.
- Figure out how to detect gamepiece positions with sensors
- Design a robust software strategy for all permutations of sensor input.
Step 3 is pretty critical - before trying to even discuss software, the mechanical design team needs to be able to show how someone with eyeballs and a brain will manipulate the parts of the conveyor in a way that picks up, moves, and ejects gamepieces in the order & spacing desired. If they’re struggling to actually do this by hand, you’ll have a rough time getting anything to work under software control.
A critical set of questions to ask when doing step 3 - for each “move” that the conveyor requires, does the move require you watch a gamepiece to achieve a certain position? Or could you close your eyes and just count out the right number of seconds, and the piece will achieve the right position?
Step 4 is also very critical, but more electrical/software team focused. That’s where you get to take the “requirement” that comes from step 3, and figure out which pieces of information you actually need to accomplish the control strategy developed in step 3. Some simple conveyors with only one game piece might need a single “thing present” sensor. Others may need multiple sensors, or sensors that can detect the shape of the gamepiece to stop it at different positions.
And finally, only in step 5, do you start writing the software. Be sure to account for all conditions (ex: what if your code resets mid match with gamepieces in the conveyor?). As with most things, start with motors running slow to prove out the concept works, then crank up the speed to achieve performance.