Ball bouncing out of the high Goal

[Wayne TenBrink]

I wish FIRST had modified the goals to reduce or eliminate bounce-outs early in the season. I think it is a bit late to do it now. Although the definition of a "scored boulder" addresses bounce-outs, I really hope that FIRST didn't intend to see this many. In an ideal world, you get credit for putting the boulder in the goal and not just for doing it with some preferred trajectory.

We have struggled with bounce-outs, but of a different sort. We shoot a high angle shot from the batter (like a lot of other teams), and unless we hit the top of the window, the backspin on the ball makes it roll down the chains, bounce off the framing at the bottom of the angled face of the castle, and then out.

[philso]

Originally Posted by Wayne TenBrink

I wish FIRST had modified the goals to reduce or eliminate bounce-outs early in the season. I think it is a bit late to do it now. Although the definition of a "scored boulder" addresses bounce-outs, I really hope that FIRST didn't intend to see this many. In an ideal world, you get credit for putting the boulder in the goal and not just for doing it with some preferred trajectory.

We have struggled with bounce-outs, but of a different sort. We shoot a high angle shot from the batter (like a lot of other teams), and unless we hit the top of the window, the backspin on the ball makes it roll down the chains, bounce off the framing at the bottom of the angled face of the castle, and then out.

Have you considered reducing the amount of back-spin you are imparting on the Boulder.

In the real world, you get credit for finishing the job you are asked to do. In this case, your true objective is not really to get the Boulder to enter the opening of the Goal. It is to get the Boulder to trip the Counting Mechanism that is several feet below the opening of the Goal.

As Andrew stated, "Field is working as designed and spec'd." This means that certain solutions will work successfully and others will not. It is up to those competing in this game to find the solutions that do work.

[pntbll1313]

Originally Posted by philso

Have you considered reducing the amount of back-spin you are imparting on the Boulder.

In the real world, you get credit for finishing the job you are asked to do. In this case, your true objective is not really to get the Boulder to enter the opening of the Goal. It is to get the Boulder to trip the Counting Mechanism that is several feet below the opening of the Goal

We use a catapult and using our slow motion camera we have almost 0 back spin. We throw it just as hard as we need to in order to have a large sweet spot. Watch our robot's autonomous (low bar blue robot). Sometimes the chains just act like a swing and spit you right back out despite your design. It's almost comical how it spits it right back out at us haha.

[CalTran]

Originally Posted by pntbll1313

We use a catapult and using our slow motion camera we have almost 0 back spin. We throw it just as hard as we need to in order to have a large sweet spot. Watch our robot's autonomous (low bar blue robot). Sometimes the chains just act like a swing and spit you right back out despite your design. It's almost comical how it spits it right back out at us haha.

I mean, isn't that a result of the trajectory for a catapult? It throws it hard and somewhat flat directly at the bottom of the chains. It's physics that the ball swings with the chain and continues out when the chains gets pulled back.

[philso]

Originally Posted by pntbll1313

We use a catapult and using our slow motion camera we have almost 0 back spin. We throw it just as hard as we need to in order to have a large sweet spot. Watch our robot's autonomous (low bar blue robot). Sometimes the chains just act like a swing and spit you right back out despite your design. It's almost comical how it spits it right back out at us haha.

That's kind of like playing miniature golf with the wacky obstacles such as having to hit the ball through the spinning blades of a windmill. I seem to recall someone shooting a boulder in the high goal on one side and it came out the goal on the other side.

[BoilerMentor]

We just don't shoot such that our (nearly 45 mph velocity) shot trajectory is perpendicular to the back board and we've stopped having bounce outs. Every shot that we took that went into the high goal at our state championship event stayed in.

This isn't just a FIRST lesson, it's a life lesson. A lot of times you just have to play with the cards you've been dealt and do your best despite unanticipated challenges.

[CalTran]

Originally Posted by MrJohnston

It's a lot like 2013 when frisbees routinely bounced out of the goals - either from hitting the target with too much force or from over-filling the goals to the point they spilled out.... If it doesn't stay in, it's no good.

At least this year it's really difficult to overfill the goal. I'm interested to see the return of the pokey stick from 2012.

[New Lightning]

Thanks for the help. Yes we will be shooting with less force so hopefully that will not be an issue.

[Anthony Galea]

Also, the backboard will also absorb some of the impact as shown here

[Jeremy Germita]

Originally Posted by CalTran

At least this year it's really difficult to overfill the goal. I'm interested to see the return of the pokey stick from 2012.

There were a couple of matches at Vegas where balls would accumulate on the shelf inside of the goal. After the first occurrence, volunteers would be behind the tower waiting with the stick used to haul defenses around. These matches were definitely fun to watch.

[Sir_Fenwick]

Originally Posted by New Lightning

So I had this thought today as we were reviewing out prototyped shooters and I realized that we had a lot of force coming out of these shooters. My concern would be what would be the ruling if we shot the ball into the high goal, but there was so much force on the ball that it bounced off the backboard and rebounded back into the field. Would that still count as a score or would we have to shoot it back into the goal again?

Yes, they only count a boulder if it falls down the tower and passes through the sensors before rolling into the corral. The chains do stop almost all of the boulders from bouncing out, but there are times when I have seen a boulder launched into the high goal when the bot isn't quite square with the goal, and the ball will pass in one and out the other, and I have also scene a boulder bounce back out off of the chains. This happened to our bot maybe twice at the Northern Lights Regional. I don't think it has so much to do with the power of the launcher, as it does just plain bad luck.

[BumblingBuilder]

Originally Posted by Sir_Fenwick

I don't think it has so much to do with the power of the launcher, as it does just plain bad luck.

+1 this. While reducing strength will help, it'd be very hard to develop a way that completely eliminates the possibility of boulders falling out. Our shooter this year was fairly weak yet we had a few problems with balls bouncing out of the high goal. A boulder bouncing out of the high goal in this match costed us the quarterfinals.

[gp2013]

I have lost count of how many balls we have had pop out. Still less than a dozen overall though I think. We do have a fairly strong shot. I think you just shrug and focus on getting those points back. I don't really think it is something that the GDC can completely eliminate. The chains certainly help. Most of the time I think, as someone mentioned, our shots just rolled across the back and out.