20 point hang.

[IndySam]

In all the strategy discussion on CD so far all I am hearing is 10 point vs 30 point debate. Isn't anyone considering 20 points?

The 20 point hang is exponentially easier than 30 and I would encourage teams to think about just going for 20 and forgetting the top tier.

As a point of disclosure we are focusing on being a expert shooter and 10 point hanger with late build season flirting with the 20 point hang.

[Koko Ed]

Originally Posted by IndySam

In all the strategy discussion on CD so far all I am hearing is 10 point vs 30 point debate. Isn't anyone considering 20 points?

The 20 point hang is exponentially easier than 30 and I would encourage teams to think about just going for 20 and forgetting the top tier.

As a point of disclosure we are focusing on being a expert shooter and 10 point hanger with late build season flirting with the 20 point hang.

The fall would be less painful from the pyramid. Thus the risk would be easier to bear.

[EricLeifermann]

Originally Posted by IndySam

In all the strategy discussion on CD so far all I am hearing is 10 point vs 30 point debate. Isn't anyone considering 20 points?

The 20 point hang is exponentially easier than 30 and I would encourage teams to think about just going for 20 and forgetting the top tier.

As a point of disclosure we are focusing on being a expert shooter and 10 point hanger with late build season flirting with the 20 point hang.

I've seen/heard a lot of people say if you can get to 20, you can get to 30 just do what you did to get to 20 again. Maybe that's why nobody is talking about going for 20.

I also agree that a 20 point is way easier than a 30 point. I believe there is a way to get 20 points completely after the buzzer and in the 5 second "grace period". If we decide to implement it, I know we will be able to make up the missing 10 points from trying to get 30 during the rest of the match....

[Jon Stratis]

Given the mechanism we've designed, there is literally nothing added to go from 20 to 30 - our mechanism should be completely repeatable... give us 10 levels to the pyramid, and we'll do it without a problem!

[tsaksa]

Originally Posted by EricLeifermann

I've seen/heard a lot of people say if you can get to 20, you can get to 30 just do what you did to get to 20 again. Maybe that's why nobody is talking about going for 20.

I also agree that a 20 point is way easier than a 30 point. I believe there is a way to get 20 points completely after the buzzer and in the 5 second "grace period". If we decide to implement it, I know we will be able to make up the missing 10 points from trying to get 30 during the rest of the match....

I agree. A 20 point hang can be much easier than a 30 pointer. Most of our students would not agree, but it really could be. At least with the right design.

Our students wanted to go all the way and attempt a 30 point climb even if they did nothing else. And, that may ultimately prove to be the consequence. By shooting for the top level they seem to end up ignoring techniques that do not get them to the top. The ones they were left with proved to be the ones where an only minimally more complex mechanism got you from level 2 to level 3, so the choice seemed obvious. However, if they had chosen to do a 20 point climb from the start I can see several ways in which the mechanism could have been much simpler. It is interesting to see how much a stated goal can end up blinding you to other options. This will be an interesting year for retrospectives.

[nahstobor]

If you can do a 20 point hang, you "should" be able to do a 30 point hang.

[EricLeifermann]

Originally Posted by nahstobor

If you can do a 20 point hang, you "should" be able to do a 30 point hang.

Completely disagree. It all depends on the "route" you take to actually climb.

[thefro526]

Originally Posted by nahstobor

If you can do a 20 point hang, you "should" be able to do a 30 point hang.

Originally Posted by EricLeifermann

Completely disagree. It all depends on the "route" you take to actually climb.

This is an interesting subject.

If you look at a legal 20 point hang, the following three things have to happen.

1) Your robot made a transition from Zone 0 to Zone 1.

2) Your robot entered into a 'stable' and 'predictable' orientation in Zone 1 (locked) before going into Zone 2.

3) Your robot made a transition from Zone 1 to Zone 2.

Step #2 is debatable, but it more or less implies that the machine enters into some known configuration that allows it to go from Zone 1 to Zone 2. Depending on the method, this may or may not be a static configuration.

If you look at the 3 points above, a 30pt ascent would need to repeat steps 2 and 3, but from Zone 2 to Zone 3. Depending on the method chosen, if you can get to Zone 2, odds are the mechanism can be tweaked into something that can get you into Zone 3.

Of course, this doesn't apply for all mechanisms, especially those that rely on robot orientation changes to transition between zones, but I'd say that most conventional methods can be tweaked from a Zone 2 Mechanism to a Zone 3 Mechanism.... Which may be the reason for a lack of 'dedicated' Zone 2 climbing discussion.

[Chris Hibner]

Originally Posted by thefro526

If you look at the 3 points above, a 30pt ascent would need to repeat steps 2 and 3, but from Zone 2 to Zone 3.

This is where it breaks down. We had a great idea to climb to level 3 very quickly and easily. After doing some CAD we learned that the problem was that the mechanism interferes with the box on the top of the pyramid while getting to level 3. Level 2 was achievable, but level 3 became a mess.

[mikegrundvig]

Originally Posted by Chris Hibner

This is where it breaks down. We had a great idea to climb to level 3 very quickly and easily. After doing some CAD we learned that the problem was that the mechanism interferes with the box on the top of the pyramid while getting to level 3. Level 2 was achievable, but level 3 became a mess.

We SPECIFICALLY had to design around this problem to solve it. I agree with you, it's a real concern and I think some teams might be surprised if they don't address it.

-Mike

[tsaksa]

Originally Posted by thefro526

This is an interesting subject.

If you look at a legal 20 point hang, the following three things have to happen.


2) Your robot entered into a 'stable' and 'predictable' orientation in Zone 1 (locked) before going into Zone 2.

Some of the ideas our team considered did not have a stable locked configuration in level 1 before continuing toward level 2. All that is needed is to be above the ground and in zone 1 before contacting zone 2, but I did not see anything requiring you to enter a static state before continuing. It is possible to configure your center of gravity such that lifting off the ground initiates a reach for level 2. As long as you are off the ground and do not contact it again after contacting level 2 I think it would be a legal climb. This dynamic shift in position is driven solely on how the level 1 lift point was positioned with respect to center of gravity. It can work fairly easily for a level 1 to level 2 reach. But it is hard to make it work for a level 3 reach.

This is not the design our team went with, but there are some designs that will work for level 2 and yet cannot easily be extended to level 3. Even just the fact that the bars are getting closer together in zone 3 may limit the height of some climbs.

[Retired Starman]

That box at the top is a killer, especially if you are climbing on the inside. In addition, there probably is only room enough for one robot up there on the inside, so coordination with alliance partners is a must. In addition, you must be careful to center your robot as it goes up to the 30 point level.

The GDC is devious enough to have deliberately designed the top of the pyramid to be too small to allow a robot with a typical frisbee shooter to fit up there.

Dr. Bob
Chairman's Award is not about building the robot. Every team builds a robot.

[Jared Russell]

Our most promising climbing concepts (including the one we are building) came from initial ideas with fewer restrictions on them.

Assume there is no shooter or floor pickup. Assume you can use the entire space of the robot. Assume there are plenty of motors and weight. Assume you can control the center of gravity of your robot with some precision. Assume you only want to do a 20 point hang.

Now take the concepts you generated and start poking at them. If you have a great 20 point hanger, what would it take in order to get to 30? How could you fit a shooter around this concept? What would need to change if the center of gravity of your robot is not where you planned? Some concepts require little or no adjustment; others do.

Almost any concept can be made into a legal 30 point hanger. It's just a matter of finding the one that is simple, robust, and fits within all of the constraints you have. There were many "a-ha!" moments leading to our climber design, and while our concept is not as simple as we would have liked (we traded simplicity for speed in one specific instance), I'm pretty happy with it. But it all starts by looking at a reduced dimensionality version of the problem before tackling all of the constraints - we tried considering everything at once and it just didn't work.