How much spin is nessesary?

After seeing the 7492 build thread, it suggest to run shooters with low spin. But what I am unsure about is how much spin you need to keep accuracy. Running no spin is a bad idea due to poor accuracy, but what I am unsure about is how much spin you need to get the benefits of accuracy without increasing bounce-outs.

Highly highly suggest prototyping then. It’s going to be the best way for you to test what that is.


I challenge this mindset.



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My running assumption is that you want to shoot the lowest energy shot possible from the closest range to maximize accuracy. That would mean no spin, and just barely shooting over the edge of the Upper Hub cone.


Like lots of teams we are at this point just shooting at a glorified hula hoop. I’m not particularly wild about the idea of nearly $1k to get the AndyMark top goal, but maybe that turns out to be a big advantage?

Why not make prototypes and try ?

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We do not have space to build a proper upper hub

You might be able to compensate with a hula hoop. If you cannot throw together a makeshift goal to shoot at…

your best bet would be go low. If you build a shooter but dont have the means to test it, you will not be seeing much scoring. Check out the Everybot build thread here

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The reason you’d want to avoid spin is because it adds more energy to the ball which causes it to bounce out. The balls are very rubbery so you want the least possible energy in the shot (which also means barely shooting high enough to clear the edge of the basket). Since the goals are so large compared to most years you don’t really need spin to stay accurate. You can afford to take potshots this year as long as everything else about your shot is decently tuned.

I would second what @Aaron_Li said. If you don’t have the ability to iterate on your design with prototyping (not even the ability to move to a gym with a larger space that you could just test out a shooter or two), then I would suggest going low. You can much easier test your robot and make sure it does what you want if you go low.

Why am I saying this?

Because at the end of the day, practice is what will make you stronger. It’s helps you break the robot so you can build it back stronger. It helps you prove your mechanism is working better with each iteration.
Without the ability to have a high goal, how do you prove that your robot is working? How do you know it’s producing the right amount of backspin that you want?
If you’re dead set on creating something to shoot high, look to see if you can find somewhere, anywhere, to test it. Even if it’s just shooting into a raised trashcan (or hulu hoop) from against the wall. Make sure you have the ability to prove to yourself it works, you deserve that much.

If you choose to go high regardless:
I would check out some of the Open Build Threads like 4481’s. You might be able to gather knowledge from there.

It is always a huge advantage to be able to drop the dough on getting ‘real’ game elements. It seems like every year, there’s an unintended ‘gotcha’ between the real field and any type of mock up. It would be very beneficial if some of the teams who had the funds to buy the real upper hub and shoot at it posted their data to help out the teams who can’t afford it.

Obviously, it’s been a huge benefit to see one or two teams shooting at representative goals. They deserve a big ‘thank you’ for highlighting this potential problem.

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I don’t think the makeshift goals are good enough for testing. It can test accuracy of shots going in, but can’t test bounce-out which makes it difficult to tune amount of spin.

And we will be going high.

What I’d say at the moment is that no one has a definite answer and it’ll depend on the shooter used. Yes, spin is useful, but it seems like it might be a worthwhile trade to go for very low spin and guarantee that your balls won’t bounce out in sacrificing accuracy. I don’t know how much this will sacrifice accuracy, but that will have to be prototyped regardless.

This isn’t the first time people have built low-spin shooters, most notably top rollers last seasons so there should be more than zero understanding of how much of an impact reducing spin has on accuracy.

Ever heard of “Your Mileage May Vary”?
The solution one team found may not work for another team.