Are the mandatory bumpers helping or hurting?

FIRST General Forum
1

As I am sure you all have noticed a specific build of bumpers are mandatory this year.

I would like to find out how many people here believe these bumpers are improving design and gameplay, increasing the spectator enjoyment of the game, preventing damage to robots or field components, preventing intentional tipping, making running a regional easier, or contributing to the events in another way I have not thought of.

Personally I do not believe bumpers are assisting the league at all.

From a spectator perspective they make the robots look more uniform. This I do not believe is a positive aspect because it makes it harder to tell simple box-like robots apart.

Bumpers do not improve design and gameplay. The 2/3rds covered rule means that generally objects can only be taken in from one side of the robot. This severely limits the design constraints and also forces the robots to become far more uniform.

Bumpers in practice do not prevent damage to robots. If for no other reason these bumpers add an additional 15 pounds of mass to the robot that now will ram full speed into other surfaces. Additionally, the bumpers appear to be giving a false sense of security to the drivers. After attending regionals (both in person and via webcast) it appears that drivers are driving more aggressively because they believe that bumpers will protect them and the field components. I know a team whose kitbot chassis was snapped by one of these aggressive drivers through both sets of bumpers. That is an incredible amount of force.

Damage situations to the field appear even worse because while other robots may have bumpers on them, the field components do not. This means that drivers can now ram rather hard into field walls without fearing damage to their robot but that the field walls may still sustain damage. Padding the walls would add weight that must be shipped from regional to regional, setup and takedown time and complexity, and make the overfall field far more expensive. I do not believe that is the solution to this problem.

Mandatory bumpers do not assist with preventing tipping.

In terms of physics mandatory bumpers should assist with intentional tipping a little bit but this is in reality a disservice to the students. The reason bumpers help is not because they prevent wedged-shaped robots particularly effectively. True wedged-shaped robots are few and far between. When was the last time you saw a robot that tipped another robot by getting under it? Instead most tipping happens by hitting a robot hard when it is most sensitive to a hit, for example while turning, reaching up high or descending a slope. Instead the additional fifteen pounds of mass is lowering the center of gravity of the robots and making them physically harder to tip. This is a disservice to the students because it is watering down one of the fundamental engineering challenges of building a good robot. Giving the students a false sense of a “rule of thumb” of “will that work” for center of gravity will only hurt them later and damage their ability to build future real-life solutions to complex problems.

Additionally, despite the physics, there is the fact that despite the extra fifteen pounds of mass to help out the CG a tremendous number of robots still wind up on their sides by the end of the match. This is probably because drivers are driving more aggressively and hitting harder.

Bumpers are an additional hassle to running a regional. Having bumpers adds time to the robot inspection process. This would be easier if they did not have to be weighed separately because then the problem could be solved with more volunteer inspectors. Instead, since there is generally only one scale at a regional it puts additional weight in what is already a bottleneck in the robot inspection process.

In short I do not not believe the mandatory bumpers are doing their job in preventing damage to the robot, other robots, or field components. Additionally they have many other negative effects. I am eager to hear other people’s opinions on this topic.

2

I would like to see this years game played without bumpers. Then tell me that they don’t prevent damage. I would rather wait 5 extra minutes during the inspection process and add 15 pounds, than have to do serious repairs after every single match.

You talked about the kitbot chassis being snapped in half even with bumpers. Imagine the damage to both robots had there not been bumpers. Even if bumpers were ruled as no longer mandatory, I would force our team to use them because I don’t want my mechanical guys working their butts off after a simple practice match.

The bumpers do not have to make the robots look uniform, and they don’t. If you look above the bumpers, robots are vastly different and can take many different shapes and forms. On our robot this year, we only covered the corners of the robot, while still covering 2/3rds of the robot. Our bot looks different than any other robot out there, and the bumpers help to make it stand out. All bumpers don’t have to be the same color, and we used that to our advantage.

3

Honestly i cannot see how they are hurting.

Why I am not the biggest fan or advocate of bumpers, I do see where they help alot. Hearing those bangs of robot on robot, metal on metal contact were awesome in teh old days, but robots got BEAT UP. It was not uncommon to see teams rendered completely useless after an intense match.

Also a lot of the conclusions you draw come from the fact that this game is a lot different. How do you know bumpers aren’t helping with tipping? I know that this is a crazy game where robots are hitting corners at top speed and going over, or they are getting caught up on an overpass with their arm and going over, but there is not really a way to say that tipping is more prevalent this year over previous years. Different game, different story.

4

Bumpers come in a variety of colors, and many teams put their required team numbers on their bumpers. The difference in bumper color helps tell robots apart, and having the team number in a uniform easy to see place helps as well.

Having a bumper over your frame didn’t limit intake of this years game piece, or at the very least, shouldn’t have. We lifted our ball over our bumper in the process of collecting. If they keep this rule in the future, and we move to smaller gamepieces, then teams will have to be more innovative in their design should they decide to collect over their bumpered sides.

Additionally, FIRST didn’t limit frame design. By and large most robots you see look pretty darn similar, typically a box about an inch under the width and length limits. And, if teams want to build different frame designs, there is nothing stopping them. See 148’s frame this year for example. I think what you’re getting at though is frames with indents for ball collection, and while I can’t remember seeing any this year, I’m sure there are some, but it also means that people found ways around it, or decided it wasn’t necessary.

Is there a picture of said KitBot? What do you mean by “snapped in half”? I’m willing to bet the team did not properly support it. Going from personal experience (yes, it’s a fallacy, I know) bumpers do prevent damage. In 2006 three sides of our robot had bumpers, the forth was left open for ball collecting. We never had any problems with the other three sides but we had to replace the front rail 3 times! And each time it got stronger. To be fair, we started out with diamond plate, but we ended up with 1.5" C channel, supported with some 1" flat bar. It was not an essential frame component, but we knew it could be bent in, so we purposefully tried to avoid hitting anyone with it. And it still took a terrible beating.

I’ve never worked on the field, but from the drive team’s perspective the only typical damage to the field is to the carpet. I can see the point of bumpers making driver’s drive more aggressively, but the carpet always gets ripped up. Was there more field damage at your regional?

Robots have tipped since the beginning. Robots will continue to tip. Bumpers don’t really help much in this regard, but they weren’t meant to. Because of the simple fact they are an extra 15 pounds on the bottom, they will help a little, as you say, but smart teams will build this into their CoG calculations, no rely exclusively on them to counter balance a 50 pound grabber 10 feet in the air. Additionally, you shouldn’t have seen any wedge shaped robots on the field. They have been illegal since 2006. And, if 15 pounds of bumper weight is a disservice to learning about engineering, should we require teams to mount their battery 2 feet off the ground? No! That’d be silly. The 15 pound bumpers are just another requirement of the design, which is a real world constraint.

I think they are much more of a hassle to the team than the inspectors. It’s pretty easy to hop a set of bumpers on the scale between robots, and then all the inspectors need to do is say “Yup, under 15 pounds.” Weighing and sizing with them on would definitely be a work saver for the team however. But the benefits they provide on the field outweigh this inconvenience on Thursday.

5

I completely understand why FIRST wanted to make bumpers permanent in this game because they are needed. But really only for this game. I graduated from high school and then came to India in 2005 so I wasn’t really able to see matches up close with bumpers but I think that bumpers kinda make FIRST games look slightly more nerdy and not so captivating, to an outside observer. Most people will look at Battlebots and will continue to watch it because you will see some metal on metal action and this is now not as prominent in FIRST, although I’m not saying that it should be. But if a complete stranger to FIRST glances at a match and sees some hardcore defense going on and gets into it then he will learn to true beauty of a FIRST game.

Also I believe that teams understand that bashing into other robots isn’t really going to get anything done and the real way to win a match is to play the game and score points.

So what I’m saying is that the bumpers should not be mandatory.

6

Yeah, 2007 was the first year (besides primitive custom job in 2003) that 1075 has used bumpers… in 2004 we got hit by a robot in autonomous at the Wonderland Invitational so hard that they bent our frame several inches to wedge it against our drive wheel. We had another match less than 10 minutes away, so out came the sawzall.

7

I will have to disagree with you here Katy.
Bumpers most definitely aid in preventing robot damage. It’s clear even from just looking at robots with bumpers in 2006/2007 against those without. In a PRACTICE MATCH in 2006, 116 fielded our robot without bumpers (because we had them removed to work on the robot earlier). We left the field with a 1" dent in our box channel frame. In 2007 we added bumpers, and despite being the focus of much more defense than in 2006, we suffered no damage to our frame. Parts of the robot not covered by bumpers (such as our “hood”) were significant dented.
The team I now mentor, 1712, didn’t use bumpers in 2007. The '07 bot has significant denting to the corners of the frame that was already present after only one regional. I also noticed a much higher incidence of items such as wire ties breaking or bots coming loose while working with them at off-season competitions than was true with 116 during 2007.
Claiming that having a mandatory weight placed lower on the bot waters down engineering is questionable at best. It’s still quite a challenge to deal with creating a robot to interact with tall field elements and game pieces in such a high pace environment, with or without the bumpers. Many smart teams would be adding optional bumpers (per rules of previous few years) to deal with this scenario anyway.
I’ve also seen definite proof that bumpers can aid with tipping, as their geometry often has them act as “wheelie bars” for teams slowly tipping over. In more than once instance I’ve seen team balance on their frame and bumpers while pushed against the Rack or Overpass.
Aggressive driving has existed since well before mandatory or even optional bumpers rules, and I really don’t think drivers play more aggressively with or without them (ever watch the 2002 and 2003 games?).
After the 2006 game, I really don’t want any team I’m involved with to field a bot without bumpers. I’ve seen first-hand the damage that can be caused by harsh defense and metal-on-metal contact. I’ve seen bots who have a 1" steel pipe serving as their “leading edge”. I don’t want that smacking directly into my robot at even mild speeds.

8

The point I was trying to make is that drivers are driving more aggressively because they believe bumpers will shield them. I haven’t heard of a kitbot side being snapped in previous years in such a manner. This indicates to me that people are hitting much harder this year.

Point acknowledged. Unfortunately (or maybe fortunately I don’t know) we will not have the opportunity to test this game without bumpers.

You are correct. I mentioned the tipping because I was trying to find some positive aspect to bumpers but then wound up finding that a negative aspect.

The easiest example I can think of is a post on the Pittsburgh field. Additionally the issues of individuals ramming the drivers station occur not just on the first lap. I don’t think they would ram as hard if they believed their robot would sustain damage. Additionally I don’t think anything would hit anything else as hard if the robots were not approaching 145 pounds.

You are correct on this.

9

This year was our first with bumpers, and it cut both ways.

On the one hand, I don’t know how our riveted frame would’ve held up with some of the hits we delivered. On the other hand, the width added to the frame did us no favors when trying to slip past robots, which proved frustrating at times.

The one thing I like about bumpers is that they’re one pesky way of separating the well-designed robots from the not-so-well-designed. We didn’t plan our bumper mounts quite as well as we could have, and we paid for it every time we had to put on or take off bumpers. A pain in the butt to be sure, but you’ll bet we learned something from the exercise.

10

We made sure that our bumpers were easily removed this year. That was the one thing we learned in 2007, was that easily removable bumpers will save your life. We used wing nuts to hold them on but they are still a little tricky to get on and off, but a ton better than last year. That was my only problem with them.

11

I am in favor of the use of bumpers. I feel they are a good means of protection, they allow you to put less frame reinforcement in (and save weight!), and the extra weight down low helps keep a low CG. I have used bumpers each year for the last 3, and I’m glad I did.

On the other hand, I am not in favor of making them mandatory. I am a firm believer in letting teams make design choices themselves, rather than being limited by the rules. The more restrictions FIRST puts on robot design, the more homogeneous the field of competitors gets. Something like bumpers should be left as an engineering decision for each individual team. If you want to use them, you can get a lot of benefit, but it may be a trade-off with other design considerations.

12

I like the bumpers but I would like to see them be an option. A lot of teams, mine included build robots that don’t need bumpers to keep from being destroyed and without bumpers, our machines can do a lot more easier. I think the decision to use them should be up to the teams.

13

Having bumpers not only means that robots take less damage, but that they deal less damage to other robots as well. I’d much rather be hit by a robot with bumpers than a robot without them. It’s much like car insurance in a way.
Mandatory bumpers means that robots will be less capable of hurting another robot. Even if your robot won’t get hurt in the collision, will the other robot survive?

14

In my opinion, the mandatory bumpers were a good idea and appropriate for this year’s game. Since we have no idea what the next game will be, there’s no way to predict whether they should be required again, and I will be reasonably content either way.

It’s just another customer requirement. You engineer around it and move on. I strongly disagree with those who feel bumpers take away from the engineering being done. If you do the analysis on needing less structure with the extra defensive padding vs. COG issues, it can result in doing more engineering, not less. So can integration with the chassis. (I really wish we’d spent more design time on quick bumper attachment and removal.)

Given the relative speeds in this game, I can see why the GDC would feel they’re necessary. In recent history (I can’t speak to pre-2006), the games have been designed such that it was unlikely a robot would spend the entire game moving at max speed on runs the full length of the field – usually, there would be ore or two occassions for a max-speed dash, with most of the time spent jockeying for position and manipulating of game objects. In this game, extended high-speed runs are a scoring method. A robot can build up quite a bit of momentum if it’s been geared for speed (momentum = mass * velocity). They’re also a bit harder to steer around obstacles when they’re going that fast (although driver practice certainly helps). That naturally results in a game in which speed-bots are bouncing off the field structures and other robots a lot. This might be perceived as more aggressive driving - although I’ve seen a lot fewer pushing contests than in recent years, so it all depends on what you call aggressive. Having some required ability to absorb impacts has likely reduced the damage to robots and field structures, and is therefore a good thing.

15

That an engineering question. Robustness should be incorporated into all designs. If your robot cannot handle a hard hit, put bumpers on it. If you build it to take a hit, you shouldn’t have to add 6 inches to your robot’s width.

A side note: If bumpers are mandatory next year, they should not count in the size of your playing configuration. By making them not count for your starting size but then make them count for your playing size effectively reduces the polygon of support of your robot and could indirectly lead to more tipping.

In summary: bummers are good, but they should be optional.

16

I believe that most posters are missing an important aspect to bumpers.

They indicate the area of legal contact. If some robots have no bumpers and some do we have no real frame of reference as to where contact is made.

They make it easier for the referees to judge whether contact is made in a legal way rather than outside the bumper area…

I think this is a chief advantage for using them… legal contact is made at the same or similar point on every robot. Deciding where the contact was initiated (high or low) is easier because that initial contact is not made up against someone’s frame…

I like bumpers and my teams have used them from the very beginning.

I do think that different methods of attaching them should be allowed rather than the “t-nuts” and bolts method. The idea would be that externally they are all the same… cloth covered pool noodles backed up by plywood.

Thickness defined… weight defined…
method of attachment… choose and engineer a good one…

thanks!!
have a safe and pleasant year!!!

17

As an inspector, the bumpers are not a big deal. Weighing them does not slow the process down significantly, as long as the team is paying attention and has them ready to put on the scale. Having them on the robot during the rest of the inspection sometimes makes it hard to see the things we want to see, so I like having them off during the inspection.

The teams I have been involved with have used the bumpers every year they have been an option. Personally, I like them. They have saved us from a lot of damage, not only during matches, but during testing at the school and during demos, where walls and posts just seem to like to jump in front of the robot. Figuring out how to attach them so that they can be removed and installed quickly is part of the engineering challenge. This year 1379 used quick release hitch pins, and can remove / replace all the bumpers in less than a minute.

When I don’t like the bumpers is when I have to help carry the robot on and off the field. 120# for the robot, 13# for the battery, 15# for the bumpers, and all of a sudden you are asking two people to pick up and move a 150 lb object that is pretty awkward to handle, and to do it quickly and safely.

One thing I noticed last year when inspecting at the Championships was that the robots that didn’t use bumpers tended to be more beat up and had a lot more trouble at inspection fitting in the sizing box due to things being bent. I hope that there will be less of that this year due to everyone having bumpers.

18

I thought the GDC clarified that bumpers must be firmly attached to the robot frame using bolts.

19

I actually am starting to like the bumpers!

With the bumpers none of our pretty yellow paint has scratched off! :stuck_out_tongue:

But seriously I have seen some hard hits by robots rounding the corners for the turns and I think the bumpers help the situation. I never thought this game would resemble bumper cars so much.

I think they are appropriate for 2008 but I wonder if the 2009 game will include such fierce bumping as would require said bumpers. :slight_smile:

20

Alan is correct. The GDC did clarify that, here, here, and here.

The inspection checklist (Rev F, line item 30) doesn’t included a specific reference to allowable fastening systems, and first mention of bumpers in the inspection reference materials (Rev D, page 4) don’t cover fastening systems, either. The reference materials do summarize several important Q&A responses (pages 10 thru 15) including those that deal with bumper mounting (items 50, 60, 71, and 79 of the Q&A summary).

So even though Alan is right, it is not hard to see why some inspectors might have missed this point. Inspection standards are higher at the Championship, so teams whose robots passed inspection at a regional despite having a non-conforming bumper fastening system should anticipate being required to correct that when they get to Atlanta.