Modifying robot at competition?

[Jon Stratis]

Teams are allowed to make changes... otherwise you would have a lot more teams with issues than the few that have added blockers during the competition.

Further, any inspection supersedes any previous inspection. If a team builds a blocker to add to their robot on Friday, they are no longer legal, until they get reinspected. At the point of that reinspection, all mechanisms that are and were a part of that robot are required to be present. If you're sitting right at 120lbs, you can't remove a 30lb shooter in order to add a 10lb blocker - both the shooter and the blocker would be included as part of the overall weight. However, if you were under 120lbs, and could add the shooter without taking anything off, how is this different (from the point of view of the rules) from a team modifying their shooter to make it more accurate? The rules don't say anything about robot capabilities, or intended use of mechanisms, or anything like that.

In my mind, the grey area here is when a team is right at the weight limit and makes a change that includes removing something and adding something else. What happens when the team disassembles the old mechanism and uses the parts to construct the new one? Is this a swappable mechanism at this point, or is this a permanent change? What happens if a team spends an hour swiss-cheesing their robot in order to drop enough weight to add something to their shooter to make it more accurate? Do we need to collect all the metal shavings and weigh them with the robot too?

These are just some examples where teams can really try to lawyer the rules, instead of looking at the intent of the rules.

The intent of T08 is to ensure that robots designed with swappable mechanisms follow strict weight rules. It's not intended to prevent teams from making modifications to their robot.

[DanCreed3692]

Originally Posted by Donut

I'll give a little bit of the background here, since our team was responsible for 2 of the times that this happened at Wisconsin this weekend (including against 3692, 4212, and 3734 in the quarterfinals).

As noted with this picture, we played qualification match 65 against team 4212 and knew we were going to get smoked if we didn't stop their full court shooter. 71 and 167 helped 3734 add an 84" blocker to their robot before that match and got it re-inspected. I wasn't there in person but I heard there was a lengthy discussion as to the legality of the mechanism, and many of the robot inspectors at the event got involved in the inspection process. It was initially ruled legal but that any modification like this would have to be permanent (i.e. 3734 couldn't remove the blocker in future matches), but this was corrected sometime later and the blocker was ruled as a reconfigurable mechanism.

When we got picked by the #8 alliance and knew we were facing 4212 again we opted to do the same thing, this time adding an 84" blocker to 1781. Less weight to work with and some drivetrain issues meant it didn't work out as well as Friday's blocker did but it was still our best shot at advancing in eliminations since we knew we didn't have the firepower to outscore 4212.

In both cases the robots that had blockers added to them were under the weight limit and within the height rules with the mechanism added. I believe neither one had to remove any components to stay within the weight restrictions which makes the blockers reconfigurable mechanisms that could be added/removed at will.

I see the potential rub in the interpretation of "during the entire competition event", but if this was taken to literally mean no changes after initial inspection then a team could not make any repairs or improvements once they pass inspection. If you had a broken shooter Friday morning, you would just have to live with your broken shooter the rest of competition. Similarly if something failed that could not be replaced like for like (say a weld on a frame) then the team would have to remain broken the remainder of the event. This is obviously not how FIRST has ruled in the past (how many times have you seen teams "get things working" Saturday morning?), and I hope they won't ever rule this way or we might see a mass defection to the SECOND Robotics Competition.

In the 2 cases we were involved in the robots in question could pass inspection with or without the blocker mechanism attached. Here's something I'm less sure of; if the robots in question had to remove something in order to have enough weight for the blocker (say a broken shooter), are they violating R05 since weight is determined for all mechanisms on the robot in all possible configurations? Are they okay if they never use that part again (a "permanent" change)? What determines when mechanisms are considered reconfigurable and thus R05 matters?

Actually thats not true.. T08 would CLEARLY allow you to repair, modify or reconfigure ANY mechanism during the Regional (or other event)... provided it was presented at inspection (and here is the rub) and available for use "during the entier competition event".... It's really that entire competition event thats the rub... How can you honestly say that isn't in conflict with other rules and imply that you can't add new mechanisms in the middle of the competition (however there are other rules that imply you can as well)... hence the conflict between rules. However people keep pointing to other rules as implying you can do this.. however I point out.. NO OTHER rule specifically states "for the entire competition event"..

[Amy_LeadFerret]

As the team with the full court shooter about which this discussion started, 4212, I wanted to post my thoughts on how things played out at Wisconsin.

We're a second year team still learning how everything works. I read the competition manual and updates religiously during the Build Season and did not see the last-minute-pool-noodle extension coming. Because we shoot at a height of about 54 inches and saw that most bots were re-makes of the much shorter Robot in 3 Days prototype, I assumed our biggest obstacle would be making it to the feeder station and lining up. I thought through the possibility of an opponents' climber mechanism reaching above 60 inches to block our shots but also thought that wouldn't be a smart usage of time unless the mechanism couldn't produce a viable climb for the bot.

But, after watching matches in Weeks 1 and 2, I knew our full court shooter would be toast at some point but was just hoping to get as far as we could before that happened. We were ecstatic to make it to semi finals and somewhat proud of the fact that we sparked fear in the hearts of our opponents

[JesseK]

Fundamentally, I agree with allowing total redesigns or modifications at competition. The modifying team will be behind the curve when it comes to practicing with said mechanisms, which is the potential pitfall. Additionally, it allows teams who've poured hours into a design that just isn't panning out to make a change and get inspired by teams who did.

Just be glad for the fact that FRC teams who pour effort into difficult autonomous routines can't be denied their gratification. In FTC, that still isn't the case. One would think that FRC's [G19] would be feasible to implement across all platforms, given the level of difficulty and effort required.

[EricLeifermann]

Originally Posted by DanCreed3692

T08

At the time of Inspection, the ROBOT must be presented with all MECHANISMS (including all COMPONENTS of each MECHANISM), configurations, and decorations that will be used on the ROBOT during the entire competition event. It is acceptable, however, for a ROBOT to play MATCHES with a subset of the MECHANISMS that were present during Inspection. Only MECHANISMS that were present during the Inspection may be added, removed or reconfigured between MATCHES. If MECHANISMS are changed between MATCHES, the reconfigured ROBOT must still meet all Inspection criteria.


I want to see what peoples take on this rule is. To me I read this as that each robot has to be presented at initial inspection with all components of each mechanism for any configurations that are planned to be used during the "ENTIRE COMPETITION EVENT".... E.G. if you came to the competition with a robot designed to be an awesome shooter, but then suddenly see another team has this awesome device, or some other component that allows it to do something completely different. I talking adds a totally new function to your robot and you thus start playing the game in a tottaly different way because of this new mechanism it should NOT be allowed. In fact it even goes on to specifically state that ONLY Mechanisms that were present during during the inspection may be added/removed/reconfigured between matches..

We got the #1 seed, and went to finals with an AWESOME long range shooter and had two teams them subsuqently out of the blue build completely jury rigged 84" masts with plastic and netting specifically added to block our alliance partners shots. These masts WERE NOT used during any other matches, were NOT presented during initial inspection, and didn't exist until other teams saw the threat our long range shooting alliance partner brought to the table.
(much more importantly they did not exist in any way shape or form before initial inspection).
What are your thoughts. Personally I think the rule is pretty black in white, as it does specifically state that the mechanisms used for the entire competition event must be presented at inspection (implies initial one), and then further clarifies that ONLY mechanisms preesented during inspection may be added/removed/reconfigured... thus further indicating the intention to not allow teams to fabricate new mechansisms out of the blue to add whole new funcationality just to defeat other teams with a different design that is difficult to defend with the robot you brought to the arena...

As part of an alliance the had a team "jury rig a blocker" as you said, to block your shots. Please someone correct me from 269 if I am wrong, but they got inspected on Thursday with said blocker on(and on Saturday before elims started), they just didn't play with it until they needed it. Which was when we faced you in the semis. It was a valid strategy that we really only used in the 1st match as 269 prevented 4212 from even getting to the feeder station in the 2nd match.

You were undoubtedly upset over losing (who isn't?), however we all followed the rules.

Good luck to all teams in their upcoming regionals, hope to see many of you in St. Louis!

[buchanan]

Originally Posted by Jon Stratis

At the point of that reinspection, all mechanisms that are and were a part of that robot are required to be present. If you're sitting right at 120lbs, you can't remove a 30lb shooter in order to add a 10lb blocker - both the shooter and the blocker would be included as part of the overall weight.

I think this is a reasonable interpretation that ought to be explicit in the rules. Once a mechanism has been used in competition, replacing it with another shouldn't allow you to reinspect as though it never existed. What you've really done is added a new interchangeable mechanism to your robot in addition to the previous one.

We noticed this at the WI regional too, but from a different angle. We brought to the competition a robot with significant shot-blocking capability to begin with. When the improvised blockers started appearing, we didn't see anything wrong with it, but they did dilute what was once a competitive advantage for us. Ad-hoc engineering feels right and in the spirit of what the competition is about, but a line needs to exist somewhere, and the interchangeable mechanism weight limit seems a sensible place to have it.

[Tristan Lall]

This has come up before. (The relevant rules were similar in 2005 and 2006.)

[EricLeifermann]

Originally Posted by Jon Stratis

Teams are allowed to make changes... otherwise you would have a lot more teams with issues than the few that have added blockers during the competition.

Further, any inspection supersedes any previous inspection. If a team builds a blocker to add to their robot on Friday, they are no longer legal, until they get reinspected. At the point of that reinspection, all mechanisms that are and were a part of that robot are required to be present. If you're sitting right at 120lbs, you can't remove a 30lb shooter in order to add a 10lb blocker - both the shooter and the blocker would be included as part of the overall weight. However, if you were under 120lbs, and could add the shooter without taking anything off, how is this different (from the point of view of the rules) from a team modifying their shooter to make it more accurate? The rules don't say anything about robot capabilities, or intended use of mechanisms, or anything like that.

In my mind, the grey area here is when a team is right at the weight limit and makes a change that includes removing something and adding something else. What happens when the team disassembles the old mechanism and uses the parts to construct the new one? Is this a swappable mechanism at this point, or is this a permanent change? What happens if a team spends an hour swiss-cheesing their robot in order to drop enough weight to add something to their shooter to make it more accurate? Do we need to collect all the metal shavings and weigh them with the robot too?

These are just some examples where teams can really try to lawyer the rules, instead of looking at the intent of the rules.

The intent of T08 is to ensure that robots designed with swappable mechanisms follow strict weight rules. It's not intended to prevent teams from making modifications to their robot.

If the team took off their shooter to put the blocker on because with both the shooter and blocker they are over weight, then they should still pass the new inspection. However they would have to play without their shooter for the rest to the competition including elims. They would not be allowed to put the shooter back on as that would violate the "multiple interchangeable mechanisms must be included in the 120 pound limit" rule.

That is how I have seen it enforced in all my years, and how it was enforced at Northern Lights. As I am not an RI, I can only comment on how I have seen it enforced and how I interpret the rule. Final ruling goes to the LRI at each competition. Though having the rules on hand to cite never hurts, when politely disagreeing with your robot inspectors.

[Jon Stratis]

Originally Posted by EricLeifermann

If the team took off their shooter to put the blocker on because with both the shooter and blocker they are over weight, then they should still pass the new inspection. However they would have to play without their shooter for the rest to the competition including elims. They would not be allowed to put the shooter back on as that would violate the "multiple interchangeable mechanisms must be included in the 120 pound limit" rule.

That is how I have seen it enforced in all my years, and how it was enforced at Northern Lights. As I am not an RI, I can only comment on how I have seen it enforced and how I interpret the rule. Final ruling goes to the LRI at each competition. Though having the rules on hand to cite never hurts, when politely disagreeing with your robot inspectors.

How many times do you have to swap mechanisms for it to be considered "multiple interchangeable mechanisms"? Is swapping once enough, or do you have to go back to the original set up at least once? What defines a design change on the robot, versus swapping mechanisms? It's tricky to figure out... IMO, if the old mechanism is still a viable robot mechanism (still intact and could be put back on), then it gets weighed. If the team chooses to disassemble the mechanism, then it could be a different story. If they remove the mechanism from the venue (and thus are not allowed to bring it back in), then it could be a different story. I was fortunate and didn't have to deal with any of this at Lake Superior (we had no full court shooters, and thus no radically changing robots, unlike you guys!), but with North Star coming up in a few days, I may be forced to solidify my interpretation of this rule, and figure out exactly where I draw the line.

At any rate, I would encourage everyone to get their LRI involved early on if you're considering making a significant change that might, in any small way, run afoul of this rule, even if you think it shouldn't.

[Alan Anderson]

Originally Posted by buchanan

I think this is a reasonable interpretation that ought to be explicit in the rules. Once a mechanism has been used in competition, replacing it with another shouldn't allow you to reinspect as though it never existed. What you've really done is added a new interchangeable mechanism to your robot in addition to the previous one.

You say you think it's reasonable, but I don't understand your reasoning. Inspection is to verify that the robot follows the rules. There are no rules that say a robot part must remain a part of the robot in perpetuity.

If you remove an ineffective floor pickup system and add a simple bucket for manual loading at a feeder station, the floor pickup is no longer part of the robot, and should have no bearing on the inspection. If you completely replace a pneumatic catapult with a motor-driven spinning wheel, I can't see how anyone can seriously argue that the now-obsolete catapult is still an optional part of the robot and has to be counted in the robot's weight when the modified robot is inspected.

[Gregor]

Originally Posted by Jon Stratis

At any rate, I would encourage everyone to get their LRI involved early on if you're considering making a significant change that might, in any small way, run afoul of this rule, even if you think it shouldn't.

This.

[buchanan]

Maybe I'm just "borrowing trouble", but this looks to me like a loophole through which a team could bring two alternative mechanisms to the competition, present only one for initial inspection, then swap in the other if they decided the first wasn't as effective as they'd thought, effectively giving two shots at picking the best design.

I guess at some point you have to just trust people to adhere to the spirit of the rules, but it seems to me it's better to get as much into the letter as reasonably possible to forestall temptation. The "add but not subtract" approach would do this, albeit at the cost of loss of modification flexibility being the price of squeaking in under the weight limit initially. This does not seem like such a bad thing.

[connor.worley]

Originally Posted by buchanan

Maybe I'm just "borrowing trouble", but this looks to me like a loophole through which a team could bring two alternative mechanisms to the competition, present only one for initial inspection, then swap in the other if they decided the first wasn't as effective as they'd thought, effectively giving two shots at picking the best design.

This sounds like a brilliant example of planning ahead.

[Chris is me]

Originally Posted by buchanan

Maybe I'm just "borrowing trouble", but this looks to me like a loophole through which a team could bring two alternative mechanisms to the competition, present only one for initial inspection, then swap in the other if they decided the first wasn't as effective as they'd thought, effectively giving two shots at picking the best design.

I don't see why this is a bad thing? The opportunity cost is if they are at weight with one mechanism, the decision to switch to another mechanism is permanent (for that regional). In terms of "fairness", it's not functionally any different from building two designs and deciding which to use at home.

[andya]

Hi,

I'm the drive team mentor for team 4212.

Since I'm a noob, I was asking a lot of questions of everyone I talked with, both competitors and officials. I want to thank everyone I talked to for the tips you all gave me.

I asked the inspectors what we can change on the robot. The few inspectors that were there replied as long as we did not go over the set limits, we could make any wanted or needed changes anytime you are allowed to work on your robot as long as you come back after every change and get re-inspected. One inspector was adamant, any changes no matter how small or big needed to have an inspection after said change.

This was as specific as the inspectors got with me on changes, and appears the rules are subject to the officiating staff’s interpretation and implementation of the rules. I thought, by the rules, what parts you came to the competition with is what you had to compete with as long as the total robot weight did not go over 120lb regardless of the parts.