Removal of Low Bar Fabric
 

Today at the Greater Toronto Central Regional, the Field Stewards elected to remove the fabric and lower pipe from the Low Bar defense, keeping the upper frame of it on the field. They seemed to remove it after all of the flaps became too damaged for match play.

Thoughts?

-Nick

Re: Removal of Low Bar Fabric
 

Were there problems with boulders going through the low bar? How was this dealt with?

Re: Removal of Low Bar Fabric
 

Not that surprising if you think about it. With the allowed extensions, the leading edge of the robot is not necessarily the bumper It will be interesting to see what First decides to do about this. Requiring more scrutiny of robot sharp edges is one possibility. Changing the Aluminum pipe out with a lead pipe is another. (admittedly not likely.)

This is proving to be a hard game to the field elements.

Re: Removal of Low Bar Fabric
 

And to robots!

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They said it would be a penalty if the teams strategically tried to roll a boulder under the low bar from the HP station. If it was not intentional, play will continue.

Re: Removal of Low Bar Fabric
 

Can't change the field and then add a rule that doesn't exist.

Re: Removal of Low Bar Fabric
 

They appear to be trying to do just that. I was just quoting what they said on the webcast a few minutes ago.

Re: Removal of Low Bar Fabric
 

And my emotional stamina.

Re: Removal of Low Bar Fabric
 

Well, after they basically allow every match to have a field fault, I guess they can do whatever they want...

I want to see a team request a match they lose to be replayed citing the field did not meet specs. :rolleyes:

Re: Removal of Low Bar Fabric
 

I think 1/16" thick polycarbonate sheet hanging from the Low Bar may better satisfy the design criteria for the fabric than the fabric does.

Re: Removal of Low Bar Fabric
 

Hanging from rings?

Re: Removal of Low Bar Fabric
 

May have been at kickoff, but now a 15" x 30 chunk of polycarb flipping up and over into a robot would be a very unpleasant change. I can see where teams anticipated a 6 oz pipe going across the top of there robot, but not the polycarb. If the polycarb gets jammed into the robot that can be a bad thing.

Not sure what the fix is, but polycarb sheet isn't it.

Maybe flaps/ vertical strips of plastic like you see on commercial freezer doors to allow entrance and egress, That would let the robot pass but stop the boulders. The strips would stay attached. They would need to run tests on entanglement.

Re: Removal of Low Bar Fabric
 

What exactly do you suggest they do? Seems like they can do what they want when they have to.

Re: Removal of Low Bar Fabric
 

We used a flap of foam board as a low bar cover in our testing and it survived, but probably wouldn't last an entire competition.

Personally, I'd like to see a beaded curtain so robots can recreate the Britney Spears Oops!... I Did it Again artwork, but I would settle for plastic strips. ����

Re: Removal of Low Bar Fabric
 

I have been watching the event for the majority of the day, and I've seen, on several instances, boulders and the low bar interact in such a way that provides concerning circumstances.
1. Robots driving onto boulders, under the low bar. It can cause a bit of a jam, as well as damage to the robot if they are going to fast.
2. Boulders rolling through. The human player station aligns with the low bar, and with a normal toss, the ball can easily get onto the outerworks, or even past it.
I'm curious to see how they deal with this, as not only does this raise scores by, in some occasions, having easier access to boulders, it also makes penalties in regards to boulders going over quite questionable.

Re: Removal of Low Bar Fabric
 

And the robots weren't getting dinged on G12, or was it a problem that rounding corners can't fix?

Re: Removal of Low Bar Fabric
 

We built sidewalls on our robot, depending on the pipe, speed of transit, and the nap of the fabric to keep the flap out of our internals. Beads or strips would behave MUCH differently. We'd probably survive with the plastic strips, but our canopy design would have been much different with beads or strips than with the single flap. I have seen plenty of robot photos posted with similar flap/portcullis deflectors.

Re: Removal of Low Bar Fabric
 

Seems like a team update could extend G40 to include "ROBOTS and HUMAN PLAYERS." I agree, though, that the removal of the flap was an overstep. There's no way a little bit of duct tape couldn't have fixed it while they tried to find some more fabric to replace it.

Re: Removal of Low Bar Fabric
 

Duluth regionals are using bumper fabric to refurbish low bars. Saw a pic of someone with a sewing machine on the side lines.

Re: Removal of Low Bar Fabric
 

The mental image I have of this process is quite funny.

Re: Removal of Low Bar Fabric
 

On the webcast for Standish-Sterling, I saw a low bar fabric get ripped and replaced with a spare piece of fabric.

Re: Removal of Low Bar Fabric
 

FiM Southfield event just announced they are removing the fabric as well. They cited a FIRST ruling and said HP's can roll a ball all the way through once on accident, any more is a tech foul.

Re: Removal of Low Bar Fabric
 

Removing the fabric makes sense.

Adding a new penalty for rolling balls too well does not make sense.

Re: Removal of Low Bar Fabric
 

They could use chain mesh it fits the theme.

Re: Removal of Low Bar Fabric
 

You took the words out of my mouth.:D

Re: Removal of Low Bar Fabric
 

Yeah...That was partially answered in one of our Q&A questions.

The specific question that we asked was: "If a ROBOT, in the process of CROSSING the LOW BAR, accidentally flips the flap such that it no longer stops boulders from rolling through the LOW BAR when thrown forcefully, then drives through the LOW BAR, will that ROBOT be assessed any penalties, since it now enables teams to throw boulders through the LOW BAR without violating G40-1, as the ROBOT is not specifically holding the LOW BAR flap up? If the HUMAN PLAYER chooses to take advantage of this situation, are they assessed any penalties?"

However, the point that pertains to this thread is the last part. FIRST's ruling on it implies that Human Players are free to abuse the low bar throw as much as they want, since it is not specifically covered under G40-1.

It would be nice to see an official FIRST ruling on this in order to wrap up the GTC scenario. Although we're not competing this week, I can easily see this situation happening again at other regionals as a band-aid fix to the problem.

If this ruling stays, I'm sure that it'll affect other teams as well as mine, as we trained our human player to throw boulders such that we can intake them the moment we cross the low bar. If he now has to precisely control his power such that it doesn't go straight through, I think that it'll significantly reduce cycle time.

Re: Removal of Low Bar Fabric
 

It makes pretty good sense to me. The intent of the fabric was so robots have to carry balls into the courtyard. It would change the game drastically if you could just roll it through no problem.

Re: Removal of Low Bar Fabric
 

If they are going to remove the fabric at some events they should remove it at all events.

There is now an obvious inconsistency for teams to play in. FIRST either needs to fix the fabric OR remove it permanently.

Re: Removal of Low Bar Fabric
 

At GTR-C there was no readily available resources to repair or create new low bar flaps, and 2 out of 3 were damaged pretty early in the day (they received a good amount of damage on Thursday as well). Matches were run with both flaps removed to ensure an even playing field.

From the existing game rules as well as Q&A answers it is, in my opinion, fairly clear that the GDC did not intend to allow any circumvention of "carrying a single ball through a defense" method of getting balls into the courtyard. Whether that be through the opponent's secret passage, launching over defenses, or a robot moving the low bar flap out of the way. I think considering the GDC's intent, it is pretty clear that if the low bar flaps are removed, they would not like human players being allowed to bowl a boulder directly into the opponents courtyard.

In fact, I would argue that the entire point of the low bar flap as well as the lower bar, was intended to prevent this scenario. Therefore, I think it's reasonable to award a Tech Foul for the action. This is the same foul a robot would receive if a robot were to do this. Allowing bowling under the low bar would make boulder starvation much easier and possibly significantly change the game.

As far as unfair awarding of Tech Fouls, as soon as the flaps were removed, an announcement was made regarding the new rule (more like an amendment or clarification imo). Even if teams didn't hear (or flat-out ignored) the announcement, a good deal of leniency was given to human players in regard to the Tech Fouls.

The field crew had already been having problems with boulders getting stuck in the sensors of the low goals and had the referees who were on break stationed behind the towers to rectify the situation (as well as ensure there weren't more than 6 boulders at any time). After the flaps were removed, these refs were instructed to remind any human players vigorously bowling boulders that the next attempt would result in a Tech Foul. Any Tech Fouls received after this change should have been from a human player who was previously warned. Of course, that is near impossible to monitor, but I had seen refs warning HPs even in the last few matches of the day.

It's definitely a difficult situation that is not easy to deal with, but I think the team at GTR-C did the best with what they were given, and did it in a way that would satisfy the GDC and the spirit of the game. If anything, it raised the skill requirement of the human players as there was a sweet spot between the boulder staying in the secret passage and rolling under the low bar :P .

Re: Removal of Low Bar Fabric
 

Kevlar. Go.

Re: Removal of Low Bar Fabric
 

A huge shout out to teams 1816, 6044, 93, and 4230 for contributing parts or tools to the effort. Without them, the volunteers couldn't have worked in this solution!

Re: Removal of Low Bar Fabric
 

we got 20 point in fouls for those boulders because of an other hp, making us lose a rematch by 10 points. we won the original match 90ish to 40... what a way to end the day

Re: Removal of Low Bar Fabric
 

Auburn Mountainview has just removed them.

Re: Removal of Low Bar Fabric
 

A single Polycarbonate flap makes sense to me. Seems to resemble the original design Hanging from rings and limit the swing to 100 deg in both directions. I have also hear the polycarbonate was week on the defense's and need doubling up to prevent flexing.

Re: Removal of Low Bar Fabric
 

Same call was just made at PNW Auburn Mountainview after all three low bar fabrics were ripped. The final destruction was pretty epic...ripped entirely in half, the lower bar and attached fabric ended up fully clear of the outer works.

Re: Removal of Low Bar Fabric
 

You can balance it out by allowing the opposing team to throw noodles into the secret passage.

Re: Removal of Low Bar Fabric
 

I vote Mithril.

Re: Removal of Low Bar Fabric
 

Very adamant of you.

Re: Removal of Low Bar Fabric
 

^ Cobwebs. From Shelob.

Seeing what happened to 67 today at Waterford, giant spider webs could not have done worse.

Re: Removal of Low Bar Fabric
 

With the right set of defenses on the field and a little bit of HP skill, it is already fairly straightforward (and legal) to bowl all the way into the courtyard.

(The details are left as an exercise to the reader)

Re: Removal of Low Bar Fabric
 

Realistically though,it seems to me that teams that designed to go under one solid piece of fabric without sustaining damage or snags would be significantly better suited by a single polycarb flap than by a series of plastic strips or chain.

Re: Removal of Low Bar Fabric
 

And this is why you should always place class A/C in position 2 when you want to win the match.

Re: Removal of Low Bar Fabric
 

It's one of many good reasons to do that

Re: Removal of Low Bar Fabric
 

For the readers who don't like exercise, group B defenses in slot 2 and an HP off the local bowling team will get you easy rolls into the courtyard.

Re: Removal of Low Bar Fabric
 

AKA most of chief.

Re: Removal of Low Bar Fabric
 

I'll have you know that I don't like anything, including exercise.



You already knew, didn't you

Re: Removal of Low Bar Fabric
 

This is where I get to brag about my workout routine, right?

Re: Removal of Low Bar Fabric
 

We have a winner.

My favorite FIRST gameplay-related word EVER has re-appeared in 2016. Inconsistency is back, my people!

Should be fun times ahead. :cool:

Re: Removal of Low Bar Fabric
 

Gonna be fun when FIRST overreacts to all the field issues this years and has a completely empty field next year. #neverforgetnodefense2015

Re: Removal of Low Bar Fabric
 

2014-style?

Re: Removal of Low Bar Fabric
 

Our fault. :)

Re: Removal of Low Bar Fabric
 

Not being able to see webcasts today, what happened to them?

Re: Removal of Low Bar Fabric
 

Sorry I cannot find video yet.

They impaled the low bar curtain with their arm, and could not get free again. Not sure if they e-stopped or were disabled, but what I recall is that they did not move the rest of the match.

I hope someone who was there can correct my account

Re: Removal of Low Bar Fabric
 

The Waterford District has just removed the low bar fabric. Same penalty addition as every other event.

Re: Removal of Low Bar Fabric
 

Fabric is back on the low bar at GTCR. Red now, so maybe a different type? Can anyone there gives us any details?

Re: Removal of Low Bar Fabric
 

The low bars just got removed entirely during granite state practice matches. A robot that couldn't quite fit bent it pretty severly.

Re: Removal of Low Bar Fabric
 

My bet is that they sourced some bumper fabric from a nearby team. Also it looks like they are missing the lower bar.

Re: Removal of Low Bar Fabric
 

Last Waterford match had at least two boulders roll under the low bar to the far side of the field with no penalty. The whole 'intent' is really messy...

I think FIRST should be very thankful the field issues have changed the game for everyone and hasn't really benefited/hurt specific designs or strategies. Imagine the outrage if the field issues were on the batter or castle so robots couldn't batter shoot or climb.

Re: Removal of Low Bar Fabric
 

The biggest strategy problem that it could cause would be the great human players. Removing the fabric and adding a penalty would make bowling around the low bar much riskier.

Re: Removal of Low Bar Fabric
 

Yes, please.

Even if I didn't think the damage to field elements were a problem, this year was obnoxious simply because it was far too onerous to expect most teams to build all these goddamn wooden monstrosities to be able to test their robot.

Worst part is, we don't have the room to store them next year so we're going to have to take the time to take them all apart again, too. Perhaps a bonfire is in order...

Re: Removal of Low Bar Fabric
 

Red bumper fabric. Much stronger then the fabric originally provided by FIRST.

Re: Removal of Low Bar Fabric
 

Are you saying that the lowest point of the crossbar is lower than the official field drawing specs now?

Re: Removal of Low Bar Fabric
 

I feel like they shouldn't have gotten so complex with the defense. Too many options for a game of this scale in my opinion.

Re: Removal of Low Bar Fabric
 

I don't see it changing the game too much. It is going to be difficult to get a boulder across the entire field and into the courtyard especially with the bump around the secret passage.

Re: Removal of Low Bar Fabric
 

Any team that has done their due-diligence will know with any human player worth their money, it is already possible - and legal - to get a boulder into the opponents courtyard.

Re: Removal of Low Bar Fabric
 

The lower pipe has always been in the official drawing specs. It's a pipe that was inserted into the cordura fabric mostly to keep boulders from rolling all the way from the secret passage to the courtyard.

Re: Removal of Low Bar Fabric
 

It might not be 100% safe, but you could station a field reset person with a paddle with a long handle to deflect balls from going through the low goal when a bot is not near.

Re: Removal of Low Bar Fabric
 

How bad would it be to put the low bar in a different spot? If it was not directly in front of the secret passage boulders rolling under would not be an issue.

Re: Removal of Low Bar Fabric
 

Autonomous programs may assume the position of the low bar.

Re: Removal of Low Bar Fabric
 

Removing the fabric is a minor change that's not a big deal. Changing the positions of the defenses is a major change that would be a big deal if it happened.

Re: Removal of Low Bar Fabric
 

Thank you for the clarification of which bar was being referred to.

Re: Removal of Low Bar Fabric
 

My team, and i imagine many others, would absolutely have pursued a different design if the low bar was anywhere else. Changing this would have big strategic implications and be unacceptable to many teams.

Re: Removal of Low Bar Fabric
 

Here in Duluth, both Lake Superior and Northern Lights have been running pretty much all day yesterday and today with flaps made from bumper material (1000D cordura), and we haven't lost one of them. The flaps the field came with, at least on the LSR side, both got ripped in half by the third match yesterday.

Re: Removal of Low Bar Fabric
 

Standish- Sterling event in Michigan has removed the low bar material. Im not sure if anybody has mentioned that yet.

Re: Removal of Low Bar Fabric
 

At Granite State, we destroyed (ripped clean through) one low bar, so we covered it in gaffers tape and replaced it with our one spare (used on the practice field). That one has a few holes too which is also gaffed over. GSD teams, if you're reading this, please don't rip our low bars :)

We may attempt to sew the bumper fabric over the existing materials tomorrow.

Re: Removal of Low Bar Fabric
 

They removed the fabric earlier today at the Mt. Olive MAR District Event.

Re: Removal of Low Bar Fabric
 

Hatboro-Horsham is having a Tim Gunn make it work moment sewing new panels.

Re: Removal of Low Bar Fabric
 

5 regionals and 12 districts ran in week 0.5 and 1. There have been literally thousands of low bar crossings, and only a tiny minority of these caused fabric damage. I haven't looked that close at the robots that broke the bar, or if the same ones are doing it repeatedly, I'm sure the event staff know. This really seems like an inspection issue more than anything else. There's another thread about all the broken rules that aren't being penalized. At Lake Superior some fabric was ripped early on, but wasn't a problem the rest of the event. Not sure if the offending robots were fixed or the bumper fabric curtains were strong enough.

G12 The following actions are prohibited with regards to interaction with ARENA elements (items A-E
exclude any DEFENSE, RUNGS, and BOULDERS)
A. Grabbing
B. Grasping
C. Attaching to (including the use of hook-and-loop tape against the FIELD carpet)
D. Grappling
E. Hanging
F. Becoming entangled
G. Damaging
Violation: FOUL. If the Head REFEREE determines that further damage is likely to occur, offending ROBOT will be DISABLED. Corrective action (such as eliminating sharp edges, removing the damaging MECHANISM, and/or re-Inspection) may be required before the ROBOT will be allowed to compete in subsequent MATCHES

Re: Removal of Low Bar Fabric
 

The new flaps were far more durable than the initial ones. Perhaps the biggest issue is that each field only had 3 flaps to begin with - two on the field and one more on the practice field. If you looked at LSR matches, we ripped two of them in half in the first 3 matches on Friday. Yes, the offending robots immediately had an inspector in their pit helping the team's correct it, but by that time the damage had already been done.

The problem with the low bar and robots isn't necessarily sharp edges. Teams have all sort of collectors sitting in front of their ROBOT as they go through the flap. Combine that with the bar sewn into the bottom of the flap and it's real easy to get caught and pull on it heavily. The fabric just isn't strong enough to withstand the forces involved after it gets a couple of small holes or cuts in it.

Re: Removal of Low Bar Fabric
 

The fabric was added back onto the Low Bars this morning.

Re: Removal of Low Bar Fabric
 

Southfield (FiM) had to resort to the "Toronto rule" Friday afternoon. By that time the curtains were more tape than fabric.

We received an overnight shipment from FIRST of new material Saturday morning. The second match of the day, the fabric split at least halfway across its length. I watched it happen. It was not cut by a sharp object, it split when a blunt object hit it with force.

The inspector double checked robots on Friday for sharp edges, and helped a few teams add some foam padding. So there was probably some narrower leading points that may have cut the fabric on Friday. But I'm pretty sure it wasn't something that would have been disallowed on a robot for being sharp. The fabric just wasn't strong enough to take any kind of a beating, either from sharp or blunt edges.

Removal of Low Bar Fabric
 

PNW West valley removed fabric after this. Whoopsies

Re: Removal of Low Bar Fabric
 

The Granite State event just adopted the same field update.

Yes, west valley removed the fabric from the low bar right after we had successfully "impaled" the low bar fabric...

Re: Removal of Low Bar Fabric
 

Designs like this, that have low forward facing surface area and contact the fabric above the pipe, are much more likely to rip the low bar fabric and trigger a G12 violation.

Attachment 20273

Re: Removal of Low Bar Fabric
 

NC District event replaced the fabric with what looked like a huge sheet of duct tape the same size as the fabric. No more entanglement issues and it still stopped balls just as easily.

Re: Removal of Low Bar Fabric
 

I don't think Northern VA ever used the fabric below the bar, based upon the matches I saw .

Re: Removal of Low Bar Fabric
 

No no - you should always put the drawbridge in slot 2.

The REAL "10th" defense was when someone stuck a drawbridge in front of me as I ref'ed the OUTER WORKS position this weekend. It would easily make me guess which defenses were crossed in positions 3-5, especially if there were things like bumpers not leaving the zone elsewhere in the outer works.

While I 2nd-guessed and corrected myself, I was bound to miss more crossings (one non-impactful low bar crossing in particular). When viewed from the side, the draw bridge has the greatest cross-section, so it's more likely than the portcullis to assist with this effect.

Yep - GaCo ripped one in practice, then it was determined that there were plenty of other robots which would also do it as well based upon how they crossed the low bar. At first we thought we'd put it in during Finals, but then they decided not to.

Re: Removal of Low Bar Fabric
 

I liked the flaps they installed at NC. They were basically layered duct tape (maybe gorilla tape). The nice part was they still flexed like the cloth flaps. After the fix they lasted the rest of the competition including elims where robots were running into them at high speeds. I am hoping that the duct tape design is carried through to the rest of the NC competitions.

Re: Removal of Low Bar Fabric
 

Of the Low Bar substitutes I have seen, this one probably worked the best and is still very simple. Also, they installed the new ones very fast. I don't know the exact number of matches the flap was out, but our team only played one match without the low bar flap.

Re: Removal of Low Bar Fabric
 

You're welcome. :D

The fabric that FIRST had sent us seemed like a cotton or polyester fabric, with a tight weave and some elasticity to it. Obviously, it didn't do too well. Our Pit Admin went out to a local fabric store and purchased a polypropylene fabric signed for outdoor applications. This was certainly more resistant to puncture than the initial set, but not indestructible. We found that this new fabric still tore when robots came into contact with the low bar frame, but the tears were far smaller and the fabric held up through the rest of the event.