[Behind the Lines] Ep. 5 Mechanism Design with 118, 3847, and 973!

[JesseK]

I got around to watching the video this morning. Thank you all for the time and effort put into this one! There are some great tips here. I really appreciate the prototyping philosophy presented by Lucien. Lord help us if it's a high-throughput football game.

The arm and shooter bits were great too. In particular Adam's history of arms in FRC should help younger teams understand where they may excel compared to elevators in certain situations. Then there's the theory of crashing on purpose (ha). And the details in the wheels for shooters and their prototyping still show me (at least) that there's still a lot to be learned by veterans who watch these videos.

The only thing I feel is missing from the shooter portion is a tip about design of experiments: if we're trying to figure out the "best" wheel, account for larger wheel edge speeds by slowing the motor down. Of course the 8" wheel will do better at the non-adjusted speed, even if the grip/wear is a quite a bit worse than its 4" counterpart.

[AllenGregoryIV]

Originally Posted by JesseK

The only thing I feel is missing from the shooter portion is a tip about design of experiments: if we're trying to figure out the "best" wheel, account for larger wheel edge speeds by slowing the motor down. Of course the 8" wheel will do better at the non-adjusted speed, even if the grip/wear is a quite a bit worse than its 4" counterpart.

We were pretty short on time so I couldn't really do any of the simple math required for figuring out your ideal exit velocity, etc. Larger wheels may not perform better if you don't have enough torque to keep them going. Direct driving a larger wheel at to high an rpm will have much worse results than with a smaller wheel especially if the wheel slips on the game object instead of transferring energy. This is why linear shooters in 2013 had to start with slower spinning wheels and increase the rpm of subsequent wheels/motos. Also your overall strategy and packaging goals (how much room you have for your shooter) will play a role in wheel diameter selection as well.

[peronis]

Awesome episode. Going to make my whole team watch.

Thanks so much for this.