Ramp bot vs. Arm bot
 

Ramp - bot vs. Arm bot
For those who are not familiar with this year’s FIRST Robotics Competition’s game this year (Rack and Roll), please go to this link before reading this post. This will bring you to the animation that every team in the FIRST Robotics Competition watched on Kickoff on January 6, 2007.
mms://sargasso-3.arc.nasa.gov/2007/first/010607kickoff.wmv

For a more detailed description of the rules, please visit this link

http://www2.usfirst.org/2007comp/Man...FRC_Manual.zip

Now back to my original question:

What is better for the FIRST Robotics 2007 Competition, a ramp - bot or a robot that has an arm with no ramp? This is the question that was discussed at our team’s meetings during the first week after kickoff.

An arm may be able to score on the Spider Rack but if the ringers are spoiled it will not help the team a lot. Also if the Spider Rack is shaking, it will be much harder for the robots to put the keepers, ringers, and spoilers on the spider racks. Of course if your robot excels in using an arm or some way to score on the Spider racks, then that will not affect you too much.

Conversely, a Ramp - bot will not be able to score well (if at all) on the Spider Rack. So I would guess that each Ramp - - bot would play defense on the opposing alliance for most of the game. The key attribute of the Ramp - - bot is that is that it can elevate its two alliance partners 4 or 12 inches off the ground at the end of the match. This is extremely important because for each robot that is elevated 4-11.9 inches off of the ground, the alliance is awarded 15 bonus points. For each robot that is elevated 12 inches or more off of the ground, the alliance is awarded 30 bonus points. That is a lot of points if the alliances have trouble scoring on the spider racks, then the alliance with the ramp - - bot will have 30- 60 points (if the robots are able to get up the ramp).

I personally think that the ramp - bot is a better robot, because if you can guarantee 60 points for each game, then you have a pretty good chance of winning the match. This is just my opinion but I would love to hear what everyone else’s opinion and/or criticism. As a Team that will be competing at a Regional and the National Competition, we would like to know what the consensus of other teams or just people interested in FIRST Robotics.

To all Teams that will be competing in the FIRST Robotics 2007 Competition, good luck!

P.S. I am a proud member of Team 250 from Upstate New York. I encourage you to visit our website (http://team250.org/2006/index.php) or e-mail me at m.rossi@team250.org

Re: Ramp bot vs. Arm bot
 

The best bots will be able to do both.

As I see it in the finals there are 16 spots for arm bots and 8 for ramp/ lift bots. The teams That will seed highest will have very effective manipulators and will score most of their points on the rack.

Re: Ramp bot vs. Arm bot
 

The problem I see with only Ramp/Defensive bots is that you are at the mercy of your alliance. The more robots that can lift other robots, the more interesting the Rack becomes. Think about it, if both sides can lift then everything depends on the Rack.

5 in a row gets you 32 pts negating one lifted robot. One more negates the second lifted robot(both over 12 inches). So should you try to get a row of 6 or try to lift 2 bots up 12 inches?

One thing is certain this game requires very dynamic strategies that can change in at any second.

Re: Ramp bot vs. Arm bot
 

That is very true but if you have an arm bot you are also at the mercy of your alliance partners. If they have bad ramps or no ramps at all then your team is in trouble.
Also I don't think that many alliances are going to be able to get a row of 5 or 6 with out it being screwed up by a spoiler. So I don't think that a long rows will be a big problem

Re: Ramp bot vs. Arm bot
 

A ramp bot does not guarantee an alliance any points during a match. You must rely on your alliance to score any points. This is why I believe an arm bot is better, because you can score points as an individual robot.

Re: Ramp bot vs. Arm bot
 

Its all a matter of population.

Why would you want multiple ramp-bots on the same alliance?

Ring-bots will always be in greater demand then ramp-bots.

(Of course if everyone follows this logic, we will be in trouble ;))

Re: Ramp bot vs. Arm bot
 

eh?

i think you have forgotten that a ramp bot can play defense the entire game. i think the ramp bot could even pin a robot (not sure about the rules on this one). so, that negates AT LEAST one opposing robot. likely a good defense robot can entirely shut out one robot (the best one on opposing team) and do some interference on one other...

so an opposing team with effectively 1.5 bots get 6 in a row? on a moving target that has little clearance for a tube? in 2 minutes or so? wow.. that is tough. i hope you have good autonomous mode... oh wait, never mind, the defense bot will just run over there and get in the way...

when you look at it from a whole, i think the best TEAM is to have 2 arms and 1 ramp bot. you won't win every match, but on the average you'll likely do well.

2centz
slloyd

Re: Ramp bot vs. Arm bot
 

If you hold the row of 6 till the end(fight the spoilers) then you have a net gain of 4 pts over 2 lifted robots of the opposing alliance!

You can only pin for 10 sec, and this year I believe they are going to be very aggressive on pushing an shoving penalties.

In the beginning I also believed that the clearance is going to a challenge but when you consider that fact that the ringer is flexible 30 degrees offset hanging is not going to be terribly difficult...

Re: Ramp bot vs. Arm bot
 

that is the problem. unless you go team by team asking what are you guys doing, then you just have to bring whatever you have to regionals and do what you say you were going to do.

Re: Ramp bot vs. Arm bot
 

What about a both bot ??:rolleyes:

Re: Ramp bot vs. Arm bot
 

If it can do both reliably, all the better.

Re: Ramp bot vs. Arm bot
 

We thought about that too. But we came to the conclusion that it would be better to focus on one attribute and make that work perfectly. If there is time later then maybe we will try to use the attribute we left out (the arm or ramp). But honestly that is very unlikely so I personally think that we should just go with our idea and hope that our alliance partners will be complimentry to our robot. Like Dominicano0519 said, unless you plan on asking every team, then there is no way of knowing who will be building what kind of robot.
By the way, I noticed that some of the replies cam from people who are going to the Finger Lakes Regional. Team 250 will also be competing at RIT, so I will see you there! Good Luck!

Re: Ramp bot vs. Arm bot
 

That is our goal. You know how that goes. Weight might be a problem.

Re: Ramp bot vs. Arm bot
 

Just something that I forgot to ask: For those of you that voted "Something else" on the poll, what did you mean? I would love to know...just to see what what you thought up.
Thanks!

Re: Ramp bot vs. Arm bot
 

Being able to lift two robots 12 inches every round definitely does not guarantee 60 points every round. There are many instances when one of your alliance partners may tip over, become immobile, or just might not be able to get back to the end zone in time.

Re: Ramp bot vs. Arm bot
 

The three teams I have/am working with are all making both bots, ramp and arm, it is quite feasible.

I am a huge supporter of playing defense, check out the elimination matches in Boston, defense was the strategy that worked best for us last year. However the fact that we won Boston it was because we were picked by the two most dominate bots, if we could shut down 1 bot on the other team they could out score the other two. The problem with playing defense is that you won’t seed well; you need to be paired with high scoring bots to win. You are much better off building a bot with a good scoring mechanism (arm) and a powerful drive train. You are not guaranteed to get picked if you are just a ramp bot. The 60 points are not guarunteed, the last two years there were pretty easy ways to score at the end of the round (in 2005 there wasn't even a ramp) and allot of matches alliances just couldn’t do it. If there are 8 bots at Rochester that can score even 2 or 3 tubes and can be an effective ramp, you can almost guarantee that a pure ramp bot won’t be picked.

If your team could use some help especially with the strategy portion of the game PM me, I am over at RPI, I don't have a car but I could get over there a couple of nights to meet with you. I talked to your mentors at the RPI/GE FLL competition

Re: Ramp bot vs. Arm bot
 

Well, our conclusion to this was to build a bot with an arm. To have a bot with an operable arm guarantees points for your alliance. To build a ramp bot you really are dependent on your alliance to get up on you, not fall down on their side, not be ramp bots too, and have the ability to score points without you helping offensively. SO, in my opinion it is a good idea to build an arm with as few degrees of freedom as possible and can place a tube on the spider leg in one swoop. Then, if you get your arm working smoothly with time left in the building season, build your ramp. The only pro for a ramp bot is that it can be an effective defense player

Re: Ramp bot vs. Arm bot
 

In my oppion the best way to look at this is to build the robot so that it can place the ringers on the "Spider" and then after that is done and perfected you can move onto the ramp.

also building a ramp-bot make the assumptiont that your other 2 teammates will be able to score the ringers on the "Spider"

If your allience is made up of 3 robots that can score the ringers is better than a team that has 2 ramp-bots and one scorer.

perfect alliance 2 scrore-bots, 1 ramp-bot that can lift two other bots

Re: Ramp bot vs. Arm bot
 

how about: perfect alliance 3 score-bots, one of which can lift the other two

Re: Ramp bot vs. Arm bot
 

the upper echelon teams will be able to score effectively on the racks, the ramp bots, though trivial in terms of strategy to get 60 points, is only true if your two random partners can fit on your ramp. A wide bot wouldnt fit on a bot that was built with a ramp that was narrow. We cant just assume that all bots will fit on everyone else's ramps and vice versa. The only guarantee is that if you built an effective ringer scorer, you have a great chance to score a lot of points.
Last year, I assumed everyone was building a robot that would go on the ramp since that was a guarantee 25 points. That was not true. At the end of a match, if your alliance is losing, your quick decision might be to move spoilers or add on more ringers to empty positions.
I'm just saying, it all depends.
Just my .02 cents.

Re: Ramp bot vs. Arm bot
 

The biggest problem with a ramp bot is the fact that you have to rely on your alliance members. I suspect that out of 10 matches (if you have the capability for the 60 points) that you would get it once. Look at the ramp last year, the only time it really got used heavily was during the elimination rounds. Always as the last minute thought, where one team usually didn't have time to get up. Now imagine your robot turning into that ramp, i really don't want a team rushing up on top of my robot to try and score some last minute points. Building a good ramp bot is not a guaranteed 60 points. Don't get me wrong it will happen, just not during the qualifiers when you need it to.

One of the greatest lessons I have learned in designing robots for FIRST games is that you have to account for one of your robots not being functional (or sometimes just useless :(). If you want to be successful you have to be able to win the match almost by yourself. I don't want to count how many non-working or barely operational robots (we have been one before too :o) we have played with. Not until elimination rounds of regionals or at the championship will you usually get capable working robots to play with, i just wish it was always like that...:D

Re: Ramp bot vs. Arm bot
 

Hmmm... Our team made sure that getting back to the ramp in the last 15 seconds was ground into ALL of our alliance partners collective heads. It was definately premeditated. We used it all throughout competition. In most of our winning matches, three robots were up... and when they weren't, it wasn't for lack of trying.


... Maybe that was just us.



I think that a ramp bot will be an important part of any "winning" alliance.

Re: Ramp bot vs. Arm bot
 

This is a different year, and a different game. Ramp bots will be useful, especially if they are driven by a good driver, capable of playing excellent defense. I am willing to bet that a ramp bot will be in 90% of the regional winning alliances.

Of course, defense is defense. Even against defenders. That is, you could easily send two of your alliance robots to the end zone for 30 bonus points, and have the third partner block the ramp bot from the opposing alliance from getting to their home zone. FIRST's rule limits access to an opponents end zone, but it doesn't prevent a complete lock out. Oh, and the pinning rule comes into effect after 10 seconds (dirty defense-- just a thought, I'm not recommending it).

The more I think about how a match will play out, the more I see the importance of making good strategic decisions. Moreso than in other years.

I think ramp bots will reign this year, especially if they can cap (even the bottom row only is still a cap), and definitely if they are good at playing defense. If they aren't apt to seeding, then they'll be selected.

I agree with someone who posted above that a capper (that handles all three rows) that can also play the end game for a 60 point bonus will probably be a force, especially if not very common. But a do-all hybrid with two cappers isn't much different from a capper with two defensive ramp bots.. why? Because of the defense. Shut down the most threatening cappers, and leave your one capper to do some work. You have two ramp bots on your alliance, did you pick well?

Maybe I'm making a strong case. But one point I'm hoping to get across is to not count out the ramp bots. Another point is that while it may be good to cap, you may not be able to come out on top, at a regional with good ramp bots, if you don't have the capability to get the 30-60 point end game bonus.

I think autonomous is important this year, but only if an alliance is good at it. Being able to place three tubes before the start of the match would be a devasting advantage. I mean, think of it, you could have a row of 5-6 within 10 seconds of the match. However, I'm not going to pay much attention to autonomous, because I have a feeling that most teams won't be able to do it, and even if there is an alliance on which all teams can cap in autonomous, how will they ensure that their robots do not crash into each other, by locking on to the same light?

Woah, and that's just a warmup.

I'm glad there are scrimmages before the season gets under way. This game is a BEAST to think about sometimes. I'm hoping the reality will be alot simpler.

Re: Ramp bot vs. Arm bot
 

I agree. Team work is certainly important but sometimes you just have to go solo...

Ramp bots will make a difference but I think a good offense will find a way to counter

The real fact is that you are too dependent on the alliance.

Re: Ramp bot vs. Arm bot
 

Our programmers are working on that very problem as we speak :)

Having a handful of auto modes looks to be really helpful this year. For example, one could select to go either down the right side, the left side, or the center of the field, looking towards whichever direction the lights will be in those starting configurations, then driving towards the light(s) after going straight for a while, then turn in and hang your keeper on "your" side of the rack, while your alliance partner is doing the same on "their" side of the rack.

Auto defense could be interesting too....15 seconds to drive around leaves a lot of possibilities

Re: Ramp bot vs. Arm bot
 

I don't think that teams crashing will be as big of a problem as you think, if you have your bot drive forward some first it quickly becomes able to focus only on the light you want it to see. If a team can score 3 keepers in autonomous I think they will be the favorite to win the match. for example if they score the same row in the 1 3 and 5 columns they only have 6 points but 2 more ringers give them 32 points (and obviously anything after that is huge.

Re: Ramp bot vs. Arm bot
 

Strategy will definitely be important to the game. It will be the most important thing about this game because of the myriad of ways to score. Every year strategy is important but this year strategy will play a much bigger role. If your alliance doesn’t have a set strategy then they will probably not succeed. They also need to have a few back-up strategies in case something changes or goes wrong. If a robot is key to your plan and they fall over, then you better have a back up plan. Also it will be essential for each team, not just each alliance, to have several strategies of their own. Ultimately this year’s game will be won by the team that knows the game the best and has the best strategy.

Just a correction that I have seen repeated many times. Having a ramp bot does not guarantee 60 points. That was a typo in my original post. Sorry. However I think that getting up on a ramp will be needed to win matches. Someone above me posted that last year many teams couldn’t get up the ramp in time. We traveled to Rochester and Philadelphia last year and found that many teams (including team 250 and 229) had very few problems in climbing the ramp. If they can get up a 30 degree ramp, in 10 seconds, then couldn’t they drive up onto a ramp that is say 10 or 15 degrees? I am not denying this year it will be hard to elevate 2 robots. But I believe that it will be even harder to score on the spider rack in long rows. This is due to the fact that the spider rack will move at the slightest touch making it increasingly harder to place the tubes onto the rack. That’s not even including the opposing alliance spoiling the row!

Our team had mockups during the first week after kickoff. We had a variety of robots (my group’s was going to attempt to use an arm and a ramp) and planned on using attributes from each design to make our robot. Most of the mockups were similar but one stood out. It had a “forklift” on either side of the robot that used a pneumatic system to raise the robots above the field. This could also be used to “flip” a fallen robot back up so they can continue playing in the game.

Just my opinion. This will be an interesting season!

Re: Ramp bot vs. Arm bot
 

Spoiler: How About a robot that will Lift two others more than a foot off the ground and still can score on the rack? :yikes:

Re: Ramp bot vs. Arm bot
 

Getting 60 points will go along way towards winning a match; however, just because you can lift two robots doesn't mean that you will. There are so many things that can go wrong. Your teammates might not be able to fit, clear your ramp, get back to your home zone. They might also be disabled. Also the opposing alliance might be playing defense on you. I predict that it will be very unlikely to get the 60 points in the qualifing rounds.

Re: Ramp bot vs. Arm bot
 

For those talking about autonomous: have you investigated the "drive forward for a while" strategy with a few random orientations of the goal? The failure rate isn't that low (as far as the potential for collisions go), given the setup of the rack. I do agree with the autonomous strategy suggested (of driving forward for a while on the corners, and going straight for the rack down the middle) I just don't know how well it will actually play out. As the weeks go on, I'm sure we'll all find out for sure.

my thoughts are that in the finals, both alliances will be capable of getting the 60 point bonus (whether from having a do-all hybrid, or a dedicated ramp bot), and it will be a strategic decision as to whether or not they'll make an attempt at the bonus. That is, if your alliance can't get the bonus, then you may get left behind.

Re: Ramp bot vs. Arm bot
 

I my opinion a ramp bot is only as good as the drivers on the alliance. Trying to drive a robot on another bot with the same footprint is difficult at best. And I know that all teams will build to the fullest dimension possible making the task even more interesting.

The one thing I learned last year is that 30 degrees may not seem like a lot but many bots required a running start to get up and the number that rammed the back wall was staggering. Now imagine the back wall is your arm.

Re: Ramp bot vs. Arm bot
 

That might depend on how clever the ramp design is. 27" wide ramps on top of the robot don't need to be only 27" wide on the floor.

Re: Ramp bot vs. Arm bot
 

Good point. Although I don't think that that would happen often. Any team that can adequatly create a robot with a working arm and a ramp then I think that they would be able to find some way to shield it or protect it.

Re: Ramp bot vs. Arm bot
 

Ramp VS. Arm? How about both, duh...

The Perfect Alliance
 

The perfect alliance is 2 score-bots and one lift-bot.
this is because with three score-bots the other team is able to score without anyone trying to prevent them.
with one lift-bot the other team has atleast one bot trying to prevent them from making the points.

Re: The Perfect Alliance
 

Who says a scoring bot can't play defense, keep in mind ties in your record are decided by the average number of points the losing alliance in each of your matches had, it is in your best intrest to just score more than your oppnents can rather than prevent them from scoring.

Re: Ramp bot vs. Arm bot
 

Obviously it would be best if you could make a ramp and arm bot. But it would be hard. Especially because an amatuer driver on your alliance might crash into your arm and damage it. I think that it is better to focus on one attribute and then if there is time, try the other one.

Re: Ramp bot vs. Arm bot
 

The perfect alliance would be 3 scoring robots, with atleast one with ramps as well.

Re: Ramp bot vs. Arm bot
 

and one that makes weight? :ahh: not seeing it

Re: Ramp bot vs. Arm bot
 

the way i see it,

if you go for arm bot, you really need to know how you want to play the game, and come up with the right strategies for it. If played right, it will obviously be a great advantage for your alliance.

as for the ramp bot, it could easily become a decision maker for any match, because if you are in fact able to lift those robots high enough, that's a big chunk of points.



---
2 cents.

Re: Ramp bot vs. Arm bot
 

Here's what I'm thinking: What if your goal is to build a robot with an arm as its main attribute, but you're team is feeling ambitious and decides that if they can lift two robots 4" off the ground, that would make the robot that much more desirable. So you build the bot and you do reasonably well in the qualifying matches, but you still need to be picked by someone to play in the elimination round. If the top-placing teams are looking for a good ramp bot, wouldn't they want one that can lift the robots 12" up, making the ramps superfluous as a desirable feature?
How likely do you think it is that the top teams will want a 12"-lifting robot on their side?
Do you think that some would value 4 inches and an arm more than the above or do you think that a robot like this will have to rely on simply their arm to get picked on an alliance?
Will the points that a robot with 4" ramps wins off of them in the qualifying matches be enough to make the ramps worthwhile?
Just something else to think about...as if we needed more...:p

Re: Ramp bot vs. Arm bot
 

Thanks for replying. That was a really good point. I think if the you have a ramp bot and are not one of the top 8 seeds at the end, then you will probably be picked. This is only because I think that arm bots will make up most of the top 8. If you have 2 or even one arm bots, they are going to be looking for a ramp bot. So if you have one that elevates 2 bots 12 inches off of the ground, then you have a good chance of being picked.

If that ramp bot also has an arm that can score, if not perfectly, but here and there, then they will definitely be picked.

Just my opinion. Good luck at your competitions!

Re: Ramp bot vs. Arm bot
 

I know atleast 3 teams doing it, I only know of three because I have only talked to 3 teams.

Re: Ramp bot vs. Arm bot
 

I'll ask the Team it would be cool to meet someone from another team that is in the area

Re: Ramp bot vs. Arm bot
 

It happens every year ... most people grossly underestimate how hard it will be to score, in any fashion.

This year we have the "we are going to do it all" people. If you can do it all, then great, but I doubt you will "do it all" well. In this game it is not necessary to do it all. Not by a long stretch.

A good team who concentrates on being a two robot lifter will have a better two robot lifter than a good team who tries to do it all.

A good team who concentrates on being a fast ring scorer will be able to score faster than most of the "do it all" scoring robots. History has shown this time after time.

Now there will be the top few percent of teams who will do it all, and do it better than most, but it will not at all be necessary. This game needs great scorers. This game needs great lifters. This game is played by 3 teams playing together and will be won by 3 teams that combine to have great scoring and the ability to lift.

And of course, we will be doing it all;)

Re: Ramp bot vs. Arm bot
 

This years game is a lot about extremes, you'll have your speedy teams that can put ringers on with ease, sporting some omni wheels (I see a lot of them coming in this year), then you'll have your slightly slower defense bot that can block 90% of teams from scoring and sporting a ramp. Those are the primary designs I see, yes you may stray by being a bit slower/less maneuverability so people don't push you around, but still have a great arm, or you could add a small arm to that defense bot to get the bottom and middle rows, but it is extremes we will see.

At the regionals (especially the earlier ones) you will see the ramp bots holding about 6 of 8 top spots, being able to stop robots from scoring and getting a possible 60 big ones, is huge, especially when all the kinks haven't been worked out of the robots. But by the Nationals, I see a different story, a flip around 2 of 8 are ramp bots, you will have lots of scoring robots and all that can do well, all have had tweaks done.]

my team has decided that a ramp/defense bot is likely best bet, we have had very stable drive trains in the past, and have been able to push up to three robots at once (Waterloo 2005), and focusing on a ramp everyone can get up allows us to a possible 60 points.

Re: Ramp bot vs. Arm bot
 

i see it this way too.. i like the ramp/lifter approach if only because of its simplicity. really, you don't even need the camera for the most basic ramp bot. it really doesn't matter how great your drive train control is because you are just running interference, no precise robot movement needed. in autonomous mode you just .. guess .. your way over to the opponents area and push/shove to an amount allowable by the rules.

wouldn't it be funny though to see a top notch ramp bot vs. arm bot in the finals? ha. the match would end with the ramp bot chasing the arm bot all around trying to lift it and bring to their own zone for 30 points... otherwise tie game. :D

Re: Ramp bot vs. Arm bot
 

I know that when our team kind of split up into groups to develop concepts, my friend Andy and I came up with a bot that could do both. It was a bot that had a shallow enough slant (and a piece at the end that moved up and down as to not violate the "wedge shape" guidelines) that a bot could easily drive up on top of it.. as well as an arm that would be used for scoring and lifting.

Andy and I liked it... but apparently it wasn't as good as some of the guys' ideas...

I still think that the most successful bots in this game will be able to do both, but that's just me....

Re: Ramp bot vs. Arm bot
 

Say one would make a light duty arm to add to a ramp bot, it's the first time me or my group do FIRST, so I'm wondering how in the world I'm going to make this arm move. I'm thinking of a motor with a worm drive and its rack gear connected to the upper part of the arm, any suggestions whether this will work?

Re: Ramp bot vs. Arm bot
 

You can only use the motors that come in the kit of parts, so you have to figure out a way to make one of them work. Also there are rules about what you can and cannot modify on the motors and built in gearboxes.

REad the FIRST Guidelines, Tips, etc manual on this page it will give you information about the motors, how much torque they can produce, how fast they turn, etc. Ask a mentor about how to understand the numbers, or maybe search on this forum for where someone else has already asked the same questions you have.

You probably will need some type of additional gear or chain or other kind of speed reduction to get the motors you have available to be able to lift the arm without breaking or overheating.

Also look for pictures of robots from past years competition, such as 2005, there were a lot of arm type robots that year.