Hello y’all! So recently, I started developing a flywheel based shooter that would be able to fire full court, and at a high enough velocity that it would consistently turn the flags. However, I have encountered issues while trying to build a single wheel flywheel. I’ve built a double flywheel shooter, and I’ve had far more success with it.
So, I was wondering:
1.what I could do to possibly improve the performance of a single wheel flywheel (the wheel has been rubber banded, and the hood is relatively smooth)
2.what are the benefits of using a dual wheel system? I know for a fact they are much less compact, so I was wondering if any benefit you’d get would outweigh that
Hey there! There’s a lot to think about when building a single flywheel, but here are the most important things in my experience.
With a single flywheel especially, you want to make sure the gearbox is as low friction as possible. Test your bearing flats for friction before you put them on, make sure the metal pieces on the gearbox are totally flush, screw the motors in tightly so they can’t wiggle when they’re spinning the flywheel, etc. If you take the motors off and spin the flywheel, it should be able to free spin for at least 15 seconds. If not, there is friction somewhere. Figure out where it’s coming from and fix it.
Compression is always a big thing with flywheels. With too little or too much compression, the balls will undershoot. I would recommend putting some adhesive foam or friction matt onto your hood, and then tune your compression with spacers until it’s firm but not tight.
Make sure your flywheel is totally round! With the wrong wheel, shot angle will be very inconsistent. Check this out at 0:55 to see how the angle can change with the wrong type of wheel
You actually want some grip on the hood as well so the ball doesn’t just roll off of it. Friction matt and adhesive foam both work quite well.
Lastly, you want to accelerate the ball when it’s entering the flywheel. If your chain is very slow and grippy, especially if it holds the ball for too long after the ball is in contact with the flywheel, it can really slow down the flywheel before it launches. You can see at 0:30 here
that these guys actually used a dedicated mechanism called an indexer to speed up the ball before entering the flywheel. Because this roller was extremely fast and low torque, the ball spent very little time in contact with the indexer, and it was easy for the flywheel to pry it out of the roller and send it across the field.
About double flywheels, they tend to be a lot worse for these games. In the NBN round robin, there were 15 robots, 12 of which had single flywheels. These launchers aren’t magically faster, but they tend to be more consistent, lower friction, more compact, lighter, easier to tune the shot angle and compression rate on, and easier to feed. I would strongly recommend using a single flywheel.
Double flywheel gives you more area for the ball to contact, so it “grips” the ball better allowing for the flywheel to be used at an even fuller potential. I don’t know how to word it exactly, but can you kinda get me with this?
Yes, but quite poorly. Ideally the compressor should do quite a lot more compression. Foam is a great option, you can make your hood out of slightly thinner lexan to get some extra flex, or you can use rubber links on the flywheel mounts. I’m using the first 2 options right now and I used the third in NBN, all three work just fine. Hope this helps!
This does add a bit of compression. However, this is mostly for a consistent surface on the flywheel. The vex wheels have patterns that are supposed to get better grip and using bands smooths these out to get a smoother and more consistent shot.