From your observations how many teams have used Adjustable Hoods for their shooters this year?
Teams with adjustable release angle far exceed teams with adjustable hoods. Varying shooter speeds between the top and bottom rollers or angling a double flywheel (unhooded) shooter works to vary this as well.
I think most of the top scoring teams are running adjustable hoods. The only teams on the higher end of OPR that I am aware of running a fixed hood are 3538 and 4613, others may exist though.
I’m not sure what you mean, what makes the two different?
In my head they are the same?
I guess I’m probably just splitting hairs, but an adjustable hood and an adjustable shooter are not the same. The overwhelming majority of successful teams are running some form of adjustable shooter, but not all are accomplishing it by using an adjustable hood. (See team 95’s build blog for details on that.)
Thank you, will do.
Orange and Blue wheels driven independently and different speeds would enable shot adjustability, mostly spin and release velocity.
Moving the orange wheel along the arc shown would allow release angle adjustability.
This clears things in my head, thank you.
I really appreciate it.
the thing about one release angle for the shooter is that you are very limited in the distance from the goal you can score this is not specific for this game, but the goal this year serenely exaggerate that due to how easy it is for the balls to bounce out, so the balls trajectory and speed when entering the goal is very important. practically it is a nix of ballistic physics and momentum…
we understood that from day 1 so we started with 2 states for our shooter hood(using pneumatics), this mean we had 2 distances that we had good trajectory and as we got far from them the trajectory was very steep which meant some balls bounced out, now we have an analog shooter hood (using 2 servos) and now we have much less balls bouncing out, and can keep a much more consistent shooter speed which help the bouncing out ting and the stress on the system…
and From what I’ve seen so far (mainly in ISR) around 30% of teams that are using a flywheel soother have some sort of Adjustable Hood, and around half of them have an analog one
I don’t think this is going to be a good method. I think most strong teams this year are using the back wheel on the hood for increased exit velocity and reduced spin (reducing bounce out chance), and the hood is used as the sole method of varying the release angle. That is really consistent, and easy to code. We found a lot of instability when varying the relative speeds of the back wheel/flywheel
We are using one on 1706 for our robot. We’ve had good performance with it so far with pretty high accuracy. We can shoot from almost anywhere as it sits, with a slight decrease in accuracy as we move further out.
Our first attempt at a 2 wheel shooter on an adjustable hood. If the controls are right, you can control how dead (knuckle ball) the ball exits. Our thought was “The less energy the ball possesses through spinning, the less it will try to jump back out”.
Seems to work.
Notice how the power gets from the motors to the wheels.
Cons are it’s hard to build.
we had a fixed hood for port hueneme and noticed a lot of shots were bouncing out, got and switched to an adjustable hood for san diego and we had a much better accuracy and could shoot from a lot farther away
Are your team’s hood cylinders driven？
The hood is a 3d printed onyx flexture that is driven by a motor/pinion and rack on the back side, (we have an absolute encoder in that versaplanetary stack that indexes it). This has a few explanations in various threads. Including this years reveal video. This is the same concept as the 2020 adjustable hood (this thread).
The overall concept is similar to a roll-top desk. The flexible hood rides on pins (aluminum dowel pins sourced from mcmaster carr) that slide in a groove. The big development this year was the integration of the top wheels (that move with the hood). There are some fine details with this mechanism, chiefly the clear polycarbonate members to counteract both belt tension and ball force (ball compression as it passes through the flywheel)
We use a 2 stage pneumatic driven hood. One for close up shots and one for longer ranges. Works pretty well id say.
This is what my team is switching too. Hoping it pays off.
If you don’t mind, what release angles do you have with your 2 position hood? We are planning on 13° and 22.5°.
I do not have the exact angles off the top of my head because we kinda just eyeballed it. But it is safe to say that it is pretty close to the angles you mentioned. Nothing too extreme since we still need our indexer to be able to feed into it properly
We have used adjustable hoods on the past three robots we’ve built. I’m not featuring Dart or 2020 robot as it was our first go around with flywheel shooters and there was plenty of room for improvement. But the two shooters shooters below are both fully adjustable, but they use different methods to adjust them.
This is out 2021 Shooter with adjustable hood so we could shoot right up against the goal as well as all the way from deep in the trench run. The top wheel this year helped get more power behind the ball so we could make shots from far consistently.
And here is a picture of our 2022 shooter. We knew we needed some sort of adjustability to it. If we wanted to shoot from close as well as far. We prototyped a two position hood to get a close and a far shot. But found having it fully adjustable increased our shot accuracy. The top wheel on this shooter is more for reducing backspin with decreased bounce outs.
In my eyes even a simple adjustable hood that allows you to have more of a range when on the field will help. For example if you pneumatically actuated it like teams have done you can have a shot from the base of the goal, and have a shot from the launch pad range. Which will be more then beneficial. And from there you can adjust RPM to fill in the range in between the two.