Scioly.org

invisiblebanana wrote: Madcow: Are you also using the ServoCity channel and bevel gears? And I guess the bevel gears are connected to ensure that the vehicle will completely stop moving once the wingnut locks up, but it seems a little unnecessary.

Might be, might not be... if we qualify, you'll see at nats.

hmmm...

I think that's a yes

invisiblebanana wrote:hmmm...

I think that's a yes

#misleadingpeople

Sharing this here (with student permission) in case it helps inspire anyone else. They ran on Saturday, and placed 37th - terrible! But a teachable moment!

https://drive.google.com/file/d/1MlfzGX ... sp=sharing This picture captures the basic essence of their device - they wound up tacking on a piece of sponge to the brake switch, and hanging a 200g weight off the side of the chassis to cut down on the wild skidding.

https://drive.google.com/file/d/1BY-reu ... sp=sharing This is a video of the BB in action "as intended"

What really nailed them at competition was the dowel. Apparently, they took the dowel off to fit the car in their carry case, but when they reattached it, they used a screw in a different hole, meaning the dowel was no longer leading (slightly behind the front wheel). They took so much time trying to fix this issue and only got in one run during the 8 minutes. There was also too much space between the switch and the wingnut (too thick of a foam piece, or the switch shifted positions on them) so when the switch was activated, the wheels failed to lock, and the car just coasted to a stop far away from the target. 1300 points and tier 3 = 37th at NYSSO.

Major take-aways:
1. Don't start an ambitious re-design without enough time to work out all the bugs. "Don't practice until you get it right, practice until you can't get it wrong." If they had this bevel gear idea in the middle of November instead of the middle of March, there wouldn't have been so many band-aid fixes that piled up.
2. Don't get tiered. As a coach, I feel a little guilty - I could have easily done an impound walk-through with them and hopefully noticed the dowel situation. But, that was their job. Get someone else to objectively evaluate your vehicle for violations. I would hope at Nationals everyone will be Tier 1 though!
3. Remember that improving accuracy is worth more points than improving the gap. It wasn't very hard to hit the "gap ceiling" - they were pretty comfortable hitting a 30cm gap every time, and probably could have gone to 20cm with little risk. But, even if they had an additional month to test, I don't think the steering and distance calibrations were fine enough to reliably get closer than 20cm from the target.

Anyway - take it or leave it - this was just our experience from the weekend! I personally love this event, since it's the one that got me hooked on SciO back when I was a student competitor. Fun to do, fun to coach, and fun to watch! Good luck to everyone who still has at least one more BB run left this season!

How do you get it less than 20cm. Do you use wingnut to stop, because I do, and that is the narrowest I can get it with having enough room for the wing nut to reach 12 meters distance. I used wingnut and counting revolutions. Do you have any other ideas of how to brake. Also, is there electric vehicle in high school? Still active?

How do you get it less than 20cm. Do you use wingnut to stop, because I do, and that is the narrowest I can get it with having enough room for the wing nut to reach 12 meters distance. I used wingnut and counting revolutions. Do you have any other ideas of how to brake. Also, is there electric vehicle in high school? Still active?

Bigger wheels, fewer rotations. Even with moderate diameter wheels it is pretty easy to build under 20 with a wingnut brake.

AugustW wrote:Do you have any other ideas of how to brake. Also, is there electric vehicle in high school? Still active?

String works, though a wingnut system is recommended. Electric Vehicle won't rotate in until 2024, iirc.

Are there any competitions in high school that are not sci oly , but like it?

AugustW wrote:How do you get it less than 20cm. Do you use wingnut to stop, because I do, and that is the narrowest I can get it with having enough room for the wing nut to reach 12 meters distance. I used wingnut and counting revolutions. Do you have any other ideas of how to brake. Also, is there electric vehicle in high school? Still active?

Use a rod with more threads per inch. They make coarse threaded rod, which is often around 20 tpi, which you might be using, as well as fine threaded rod, which gets up to 28+ tpi.