Re: Should FIRST address "ramp bots"?
 

There are also disadvantages to wedges.

We put wedges on the sides of our robot so that when we were trying to cap, opponents would have trouble tipping us or shoving us around. However in the Archimedes quarter finals, our wedges worked against us. We were defending a goal that we owned and pushed into a robot to stop them from capping. Unfortunately we tipped the opponent and our alliance was dq'ed (disqualified). That happened to us twice in the same quarter final! However one of the opponents was also dq'ed for tipping in one of the matches making it a tie (both alliances dq'ed). We finally won the quarter-final, but, needless to say, being dq'ed twice in one quarter final didn't make our day. :(

The Archimedes referees were very strict about tipping if a robot had a wedge, and they didn't seem to have any trouble making a ruling. In our case, we were moving forward with a wedge, the opponent tipped, and we were dq'ed. I don't have any disagreement with their ruling. My point is that having a wedge is helpful when being pushed but obviously not helpful when you are doing the pushing and it gets you dq'ed.

On the positive side, this year, we saw some robots come at us so quickly that they caught some air when they hit our rear wedge and flew over us. We were happy that our robot didn't have to deal with the collisions that would have occurred if we hadn't had wedges.

I do think that the rules on pushing with a wedge need to be clearly spelled out (ie if you push with a wedge and a robot tips, you will be dq'ed) as the rules were applied very differently at different events.

Doug Hogg

Re: Should FIRST address "ramp bots"?
 

Sadly, the bumpers weren't as effective as we would of liked. The idea was amazing, but we didn't implement perfectly. I'd like to try it again next year myself. We ended up reducing the bumpers to not come out, and just remain as cushioning. We replaced one side with a rather steep flopout wedge, but since it didn't go all the way to the ground, it never came close to flipping anyone, and we were careful not to push too much with that side.

At any rate, the bumpers have absolutely no effect on a wedged bot. One such robot flipped us over in the qualifying rounds, pushing us into a vision tetra untll we tipped. This team went on to topple several robots in the elim rounds, just barely losing in the elims. Wedges are all fine and dandy, but a team with a wedge should be responsible if they flip a bot over as a result of that wedge. It leaves room for a judgement call, but a very clear one: If they're pushing with their wedge and a bot falls, they get DQ'd. The rules prohibit putting a part of your robot under another bot and lifting, and what does a wedge do except lift as it moves foward?

There's nothing wrong with a wedge to have your bot "hold" another and transfer weight, but when you make it too steep, you're lifting, not holding.

Re: Should FIRST address "ramp bots"?
 

Doug

I agree with your last post completely. I am only concerned that the refs will need to determine if the wedge shaped bot was pushing or being pushed when the tipping incedent occured. This will not always be an easy call and not everyone will take their DQ as graciously as you have.

Matt B.

Re: Should FIRST address "ramp bots"?
 

It all depends on the ramp and how it is used. Some ramps are great defensive tools, and do help center of gravity, but some are excessive or prove to be a tipping hazard. While Im sure 233's sloped edges were made for defense, I saw them once push another robot down, and heard they did at least one other time. Im not sure if they would have tipped these robot's anyway, but the ramps looked to be a very definate help to the tipping. Im also positive that they werent used intentionally. The tip I saw was during autonomous and of their own teammate.
Ramps that prove to be dangerous over the course of competition should be adressed, but not all ramps. If a team developes a record of using the ramp aggressively or of its ramp flipping other robots on several occasions that team should be instructed to do something about the ramp.
While ramps are often the simplest solution to opposing "bricks" and CG issues, their are countless others. Outriggers dont have to be ramps. in 2004 we had a "wheelie bar" that prevented us from tipping while climbing onto the platform to hang. This year Team 118 had small PVC tubes that curved down to the floor (they started parallel to the floor, and curved until they were perpendicular, so they couldnt be a ramp nor ramming spikes) that helped keep them from tipping. Also, our drive system this year was fantastic from keeping us from tipping.
For those who havnt seen it, it is a holonomic drive system, but instead of the wheels being mounted vertically along the 4 faces of the robot, they are mounted on a 20 degree angle in the 4 corners, allowing our "footprint" or Conservative Support Polygon to be as large as possible, as well as lowering the drive systems CG. Because of that, we never even came close to tipping. Also, by avoiding massive, heavy arms, ect. you significantly lower your CG.
As for defense against brick bots, there are a number of bumper designs that can beat them. Also, just having a faster, more maneuverable, or stronger robot will often do the trick. "Cattle plows" or designs that drive with a leading corner will also usually deflect the blow. Outriggers, or some form of device to "plant" you to the ground can be highly effective for holding ground against powerful bots as well (like the top of the ramp in stack attack, or the top platform last year). High traction drive systems, like many tank treads, can do a great deal to hinder bricks as well.

Re: Should FIRST address "ramp bots"?
 

Please note that my team used wedges as defense...
I think that wedges are great as long as you know what you are getting into. 2003: We used wedges to hold us on the platform and to make sure we didn't slip backwards on the ramp. As long as you came up elsewhere or backed off, you were fine. If you came up on us and tipped, and we hadn't moved, that was your problem.
2005: Side wedges. If you saw us (and most of you probably did) you know that we only had one that could possibly be used as a tipper by us. If you came at us from the side, and you tipped (as one robot did in practice), that was your problem. In back, maybe or maybe not. And at least one team (number withheld) got up the steep side wedges hard enough to damage acrylic panels pretty badly.

However, there was one robot at L.A. Regional that was a low box with four wheels and a wedge that lowered. They were careful not to draw penalties, and that is good. However, at least once they lifted a goal. Not good.

Use of wedges depends how they are used. Tip a robot or two deliberately and get DQ'd. Accidentaly and get a warning.

Re: Should FIRST address "ramp bots"?
 

I can't say I've seen more wedges/ramps this year then in years past. I can remember at least 1 robot with a wedge/ramp that went far in the eliminations at nationals every year since at least 2000, and most years it's a few. 67 was a great example last year.

If we ban one of the simple machines from being used, I think we should ban wheels as well. :)

Re: Should FIRST address "ramp bots"?
 

History with a ramp:
In 2003 we also employed small ramp-like fins. THey were meant to make a robot beach on us and hold the hill. However, a robot ran up the small 6-in or so ramp fins and flipped almost over end. (We got the play of the day for that award by the way.)

Ramps are useful for many facets in many ways. To ban them would take the fun out of it. Just have the driver watch his CoG when near a ramp bot and it'll be okay.

Re: Should FIRST address "ramp bots"?
 

At both regionals I attended this year (St Louis and Midwest) I saw angled designs. At St. Louis there was a robot that was not made for the intention to tip robots. But when they found out that it was very good at it they did. I told the driver multiple times that this is not "battlebots" and it was totally against GP. We were paired with them twice. Thankfully they got hung up on tetras and didnt have the chance to tip any during our matches. At Midwest the intent was just the opposite. 111 had a suppubly designed robot. There slanted design was used in the exact same way ours was: stability. When they had their tetras up so high, just a tiny nudge would have sent them over. It was just an innovative design and weighed much less than ours. I am totally against the intent to disable a robot, just like the major majority of all FIRST participants.

Re: Should FIRST address "ramp bots"?
 

This was my first year at FIRST.

During the regionals I saw "ramped" bots a lot. I also saw "headless" bots that were just there to provide mayhem and defensive "bashing". In fact, our own robot turned a corner too fast and we actually flipped ourselves by running up the ramped side of another bot.

BUT....at the finals in Atlanta, all the robots and their drivers/coaches knew enough to take a positive offensive stance. Each robot tened to its own area of the field like a finely choreographed dance. So whether a robot has "ramped" sides or whatever design is a MOOT POINT when you get to the teams that really know how to properly play the gam for maximizing the score. They don't waste time with defensive moves!

Next year's robot will be a "sheet of paper"; impervious to anyone elses intentions....ha, ha, ha

Re: Should FIRST address "ramp bots"?
 

Hmm.

I was coaching the other team. From my vantage point, you guys drove up on us (well onto the wedge), and we chose to drive forward. My intent was to get us to touch the LZ with you perched on top of us. I never saw you try to avoid the contact by driving in reverse (that would have put you in our loading zone and drawn a 30 pointer). We certainly never backed up. We went too far by pushing after you hit the field border - you tipped (right into the border, not into the LZ), and we (rightfully) got shut off.

In hockey terms, we tried to pull a Fedorov (taking a fall to get a call) but ended up pulling a Probert. We learned our lesson.

Ken

Re: Should FIRST address "ramp bots"?
 

Our team (11) used wedges for the first time this year, and we are sure glad that we did.

Our wedges were actually a controversial topic around week 5ish. Some of you might remember we have the aluminum "picture frame" wedges. They turned out to work great. The way we designed them, there was a good 3/4" pushing surface before the wedge started. Our wedges were one of our greater parts of the robot this year. I know many teams have had bad experiences with wedges, but they have to understand that the wedges dont come without sacrafice...

After week 1, at EVERY SINGLE drivers meeting, the topic of wedges was brought up. We learned real quick that we had to be careful with our as some people saw them "tipping weapons". The truth is that the few times we had to flex our drive train muscle, the wedges gave us the advantage we needed. A couple of robots were flipped, but none of them because we drove into them and they flipped. Other teams pushed them into us, they hit us at a high rate of speed...etc.

A note to the teams who are disgruntled about wedges...If you really can't stand them being used against you, why dont you try using them yourselves?

Re: Should FIRST address "ramp bots"?
 

This is an issue that could be addressed in game design. It seems to me that a robot with sloped sides would have trouble getting onto a raised platform; ala the 2004 game.

Re: Should FIRST address "ramp bots"?
 

Teams should already have known that from Kickoff day.

Re: Should FIRST address "ramp bots"?
 

I intend to. I wanted to see what the community thought. I'd prefer no wedge bots, but if there is no rule against it next year we will have sloped sides added to our bot.

Re: Should FIRST address "ramp bots"?
 

Unless of course the game FIRST designs this upcoming year would deter teams from using them. All I know is for us they worked great, and Im sure other teams that used them for the first time this year would agree 100%.