Welcome to team 99999v’s change up early season robot reveal!
Huge thanks to SCA for helping me figure out some of the details, and in general just being a great place to bounce off ideas and concepts.
This robot was CADded over the course of a week. It was actually the third design iteration this season, but the first to actually get constructed. Using CAD was a huge benefit, because constructing this robot was pretty smooth sailing, I didn’t run into any issues that couldn’t be fixed in a few minutes.
The robot itself is of the hoodbot variety, as most robot are. The motor distribution is as follows:
4m 333 rpm drive on 3.25" wheels
2m intakes, 300 rpm outer rollers, 200 rpm inner rollers
1m 600 rpm indexer, consisting of two 30t rubber band rollers and one 24t rubber band roller
1m 840 rpm launcher, and 600 rpm pooper
3 balls/second maximum scoring speed, 3 balls/2 seconds is the average.
4 ball capacity hood, 1 ball capacity hoarder
at a glance this looks like a very standard robot, but there are a few major innovations that I believe will become meta. The first is the pooper. This is a pair of independently controlled back rollers, the top one always spins the opposite direction from the launcher, and the bottom one always spins in the opposite direction from the indexer. This means that when I spin my launcher and indexer forwards, the ball passes up like normal. but when I reverse the direction of the launcher, the ball gets sucked out the back of the robot between the two back rollers. I’ve been calling this the pooper because it lets your robot poop balls. I got the idea for this from a robot that was briefly discussed on e-vrc cast, which had a single back roller that was ratcheted from the launcher. So the idea of using back rollers to eject balls is not mine, what I did is add a second roller and do away with any ratchets to maximize efficiency. I thoroughly believe this is way better than a trapdoor because of the speed and simplicity.
The next new feature that this robot has is a hoarder. This is literally just 2 standoffs and a rubber band on the rear of the robot, that catches and holds on to a ball that gets pooped out. Then the next ball to be pooped will push the first out under the rubber band and out of the hoarder. This doesn’t do much, but it does ensure that your opponent has one less ball to work with at all times, and comes at really no sacrifice so might as well have a little hoarder.
The robot folds into sizing by having the hood start folded down on top of the indexer, and the intakes folded back to the sides of the robot.
What I've Learned
From the experiences I’ve had building this robot, I’ve come to a few conclusions about the ideal features of this kind of robot.
I think that flaps are the best type of roller for the intakes, because they have the best pickup range for the balls, have enough compression to descore, and still allow balls to fall down onto them while continuously descoring.
For the indexer, I think rubber band rollers are vastly superior to tank tread with flaps, because rubber band rollers are very good at transferring a lot of speed to an object very smoothly and uniformly, without stressing the motors. Tread with flaps on the other hand just isn’t the best at doing this, and even with fine tuning, tread indexers just seem slower than rubber band ones. Compare YNOT’s cycle speed with 1727g’s if you want to see what I’m talking about.
I can’t really say that rubber band rollers are the best for the launcher however, as I haven’t tested using anything else. But I can say it works well enough, I don’t have any issues with the launch power not being enough once I had a proper hood on.
I’d also like to suggest that a ball capacity of 4 is the perfect amount, because less than 4 and you might find yourself lacking balls when you need them, and more than 4 means you need a longer path for the balls to travel, which means it will take longer for balls to go from the ground to your launcher.
but don’t just take my word on all this, do some tests yourself, everyone has a different robot style, and whatever works best for you is what you should do.
I hope you enjoy the reveal video, and if you have any questions I’d be glad to answer them. I will probably make an explanation video after I complete all the finishing touches to the build. Have a good season!