Poll: Turrets for Rebound Rumble

What is your opinion on using a rotating turret for this year's game? How far should it turn? How would you use it?

*This is for my own curiosity, and will not effect 256's decision making process*

[Peyton Yeung]

We felt that the ability to score with any robot orientation is important especially since the number of balls is fewer than we'd like. It is easier to pick up a ball and go for another one and still be able to shoot. We think the benefits outweighs the complexity.

[DonRotolo]

Wow, 100% no (at this time), that's pretty convincing...

We considered this, and actually did it for Aim High, but it adds weight, complexity, and doesn't add any features we can't do with drivetrain. Yeah, I guess we can't drive sideways and shoot, but if we're touching the key, defense will be a challenge. So we stop, turn and aim.

[MichaelBick]

Well, we decided that it is too risky to shoot form afar, so we are already lining up with the fender, and it should not be a problem.

[Grim Tuesday]

Originally Posted by MICHAELABICK

Well, we decided that it is too risky to shoot form afar, so we are already lining up with the fender, and it should not be a problem.

Lining up with the fender is pretty much the only place on the field when defense can be played on you.

Back on topic, the turret adds a huge amount of complexity and complication in design where it would not have been before. 90% of that functionality can be done by moving the drive train.

[Madison]

Here's something one of our members put together showing the relationship between distance and accuracy.



I will leave it to others to determine if a turret is necessary, but the precision required to sink shots from long distances is substantial.

It may be possible that hitting the backboard and bouncing balls in will be more forgiving. We don't yet have good data on that.

[dodar]

The key doesnt start at 12 feet it starts at 101 inches, which is less than 9ft.

[Madison]

Originally Posted by dodar

The key doesnt start at 12 feet it starts at 101 inches, which is less than 9ft.

True enough; though the rest of the information is correct. Teams will need to aim with high precision for long shots. I think folks are grossly underestimating the difficulty involved here.

[Chris is me]

We are adding a turret for two reasons:

1. We've done it before, easily.
2. It involves software to aim well, but you can also manually set our turret and shooter assembly for autonomous mode this year.

If either of those things weren't true, I would support a non-turreted shooter for my team. We just did well last time with a COTS lazy susan type bearing setup that we're refining for 2012.

There's rarely a question of "best" in FRC. There is only "best for your team". That said, a turret for many ball shooters is a decision with a much lower opportunity cost than, say, a swerve drive. Thus you will likely see turrets at the top of play no matter what.

[Dr Theta]

There are many factors that go into whether or not building a turret is the "best" strategy for this game.
1. Prior experience with turrets (off-season or previous years).
2. Whether you can get the desired precision with the drivetrain.
3. Motor allocation.
4. Time taken for iteration and development.

We ultimately decided against the turret due to several of these factors (one of which has yet to be determined). It comes down to realistically looking at what you can achieve, and what resources you are willing to allocate to achieve it. For us a turret may have been achievable, but it would require allocating more of our resources than we were willing to use in it's development. Whether or not this puts us at a competitive disadvantage is yet to be seen, but it is less likely to put us at a huge disadvantage compared to attempting to do more than we realistically can.

[pfreivald]

Originally Posted by Madison

True enough; though the rest of the information is correct. Teams will need to aim with high precision for long shots. I think folks are grossly underestimating the difficulty involved here.

Right-o. I think that the difference between passable teams, great teams, and awesome teams will be accuracy at range...

...and accuracy at close range is better than innaccuracy at long range (except for certain feederbot applications).

[Chris is me]

Originally Posted by pfreivald

...and accuracy at close range is better than innaccuracy at long range (except for certain feederbot applications).

If you don't have your design down at this point and you read one sentence on Chief Delphi, read this one.

[MrForbes]

Our turret so far. The plywood disc sits on a 6" lazy susan bearing. The ball is fed from the side. The shooter sits on top of this. The turret only moves a little bit, like 45 degrees. The belt is screwed to the wood disc. The pulley on the gearmotor had it's hole opened up to 10mm to fit the gearmotor shaft. Design calls for about one second to move 45 degrees, so we have about an 8:1 ratio, with the roughly 1 rev/second gearmotor.

[pfreivald]

Originally Posted by squirrel

Our turret so far. The plywood disc sits on a 6" lazy susan bearing. The ball is fed from the side. The shooter sits on top of this. The turret only moves a little bit, like 45 degrees. The belt is screwed to the wood disc. The pulley on the gearmotor had it's hole opened up to 10mm to fit the gearmotor shaft. Design calls for about one second to move 45 degrees, so we have about an 8:1 ratio, with the roughly 1 rev/second gearmotor.

Looks nice! Are you just using friction for the drive belt, or are you going to put teeth on the plywood disc as well?

[Aren Siekmeier]

Originally Posted by dodar

The key doesnt start at 12 feet it starts at 101 inches, which is less than 9ft.

Originally Posted by Manual

The Key is an elongated semicircle that is 101 in. wide and 48 in. deep. The flat edge of the Key is located 144 in. from the Alliance Wall and centered on the width of the Court.

I think you're mixing up the width with the position. The key is 144 in., or 12ft, from the Alliance Station wall, and 48 in, or 4 ft deep. So 12 to 16ft.