Shooters vs Arms

[ggoldman]

I wanted to start a discussion on the effectiveness of shooters vs arm lifters.

Here are some pros and cons I see of both:

Shooters

Pros:
Quick release
Can hurdle "on the run"

Cons:
Cannot Place on Overpass at end
Can be "Blocked" easily
Cannot (on their own) knock down balls off overpass

Arm lifters

Pros:
Can knock balls off overpass
Can place on overpass at end of game
Cannot be "Blocked" while hurdling

Cons:
Slightly slower than shooters
Possible High Center of Gravity


In my analysis, an arm lifter can outscore a shooter bot fairly easily:

If an arm bot knocks a ball off the overpass during autonomous and places a ball on the overpass at the end:

20 pt difference

That means that a shooter bot would have to hurdle 2 extra times (and pass finish line) to make up the point difference.

So the question to ask is: Can a shooter get two (or more) extra laps while hurdling when compared to an arm bot?

Please comment and continue this discussion.

[Brandon Holley]

It is very VERY hard to have this kind of argument without getting into one's opinions. In my opinion...a shooter bot can get rid of the ball MUCH faster than an arm bot can and for the most part can do that without lining up or stopping.

It really is a matter of opinion and design. BOTH in some cases will be very effective and BOTH in some cases will be almost completely useless.

[EricH]

It is very VERY hard to have this kind of argument without getting into one's opinions. In my opinion...a shooter bot can get rid of the ball MUCH faster than an arm bot can and for the most part can do that without lining up or stopping.
But then there's acquiring time... It'll probably balance out in the end.

[s_forbes]

Who says a shooter robot can't take a ball down and put it back?

Conversely, who says that an arm robot has to slow down to hurdle?

[ggoldman]

Good point Forbes!

What do you think the best mix will be for an alliance?

Two arms and 1 shooter?

1 Shooter, 1 arm, and 1 racer (just goes very quick around the track)

[Doug Leppard]

Our team has an arm. I was very impressed by the shooter, being able to do this on the run is very impressive.

I think our advantages in knocking down and placing on top will be challenged by shooters fast shooting.

The down side of a shooter can be easily overcome by good partners.

So it will be seen in actual competition how this plays out, but I am not discounting a good shooter.

Interesting you have two phases of competition, 1st being the preliminaries matches, where you might not have good partners. Second phase is the finals where you can create a balance.

I know that since we can do hybrid well and place and knock down we would like to have a good partner shooter to balance us out. So I think each will need each other in the finals.

[akash155]

concerning the blocking of the shooter, I understand this might be skewing the rule book but i was wondering if you guys might possibly consider blocking a ball in the air from the shooter as a violation of the protection while hurdling rule <G42> and even if it isn't the force that it takes to project that ball over the overpass is so great that a team would not sacrifice its arm unless it was specifically made for blocking.

[flyingcrayons]

we had a HUGE discussion about this the other day. i think that the shooter can also knock the ball of the overpass. it wouldn't be too hard

[Madison]

concerning the blocking of the shooter, I understand this might be skewing the rule book but i was wondering if you guys might possibly consider blocking a ball in the air from the shooter as a violation of the protection while hurdling rule <G42> and even if it isn't the force that it takes to project that ball over the overpass is so great that a team would not sacrifice its arm unless it was specifically made for blocking.

Once the trackball is no longer in possession of the robot -- that is, once it's been flung at the overpass -- it's fair game. Knock it out of the sky.

[EricH]

concerning the blocking of the shooter, I understand this might be skewing the rule book but i was wondering if you guys might possibly consider blocking a ball in the air from the shooter as a violation of the protection while hurdling rule <G42> and even if it isn't the force that it takes to project that ball over the overpass is so great that a team would not sacrifice its arm unless it was specifically made for blocking.IF and ONLY IF the ball were clearly away from the robot (not contacting it in any way, shape, or form) would I consider it fair game for blocking. Once the ball has left the robot, the protection of <G42> no longer applies. You do need to be careful as to where you block it, as once it has crossed, it counts for 8 points for them once it hits your robot.

Standard disclaimer: I am not one of the game designers; therefore, I am not necessarily the most accurate source of game info. Q&A is.

[GaryVoshol]

<G42> protects a HURDLING robot (and the trackball it is holding) from "overt, blatant, or aggressive contact that interferes with the HURDLING attempt." (emphasis mine) If an opponent can block a shooter without contact, and without impeding, it should be fine. This would be a question to ask in the meeting with the Head Ref on Friday morning of competition, to see how <G42> would be called. It most likely will be covered in referee training.

[Nevets Amstier]

i really think we'll have to wait until the pre-season compitions start and we see how the game is really played.

[TubaMorg]

It would be interesting to see what happens to a robot that is hit with a ball fired by a launcher into its extended blocking mechanism.

[Brandon Holley]

Like I said earlier this thread is 100% matter of opinion, while I can see shooters being very quick, i can also see the versatility of an arm. Its going to come down to ball capturability and overall effective design, just like it does every year.

[EricH]

What would really be cool is: 2 arm robots and a launcher. The arm robots capture the trackballs and load the launcher. Launcher fires, arm robot who just loaded it scurries under the overpass and grabs the ball, taking it around again. Meanwhile, the other arm robot comes in to reload the launcher. At the end of the game, the arm robots put the trackballs up, and the launcher crosses the finish line.

[MrForbes]

Eric, I guess you haven't seen how easy it is to self load a launcher with just a simple moving arm sticking out the front of it?

:)

.

[Teched3]

Inform me if I am wrong, but by definition, HURDLING is defined in the rules as the trackball ball top being positioned just above the top rail of the overpass, or higher. Therefore, unless shooters shoot from that level (minimum height), they are not considered in the act of hurdling, even though that may be the end result of their shooting the trackball. Therefore, it would seem, blocking the shot is well within acceptable defense. At least, that's my interpretation of what I have read. :) :)

[EricH]

Eric, I guess you haven't seen how easy it is to self load a launcher with just a simple moving arm sticking out the front of it?

:)

.I realize that (I've seen 118's video), but it might be more efficient if the launcher didn't move and had two arm robots supporting it--similar to 2006's "Atom Bomb" strategy. Twice the rate of fire sound good to you?

[Swampdude]

It's always true how you execute your design is the deciding factor as to how successful it will be. However 118 showed how easy it is to make a great launcher. We contemplated copying that when we saw it. It would have been easy to do (the launcher anyway). I'll bet a number of teams did. Why not?
However, all things being equal, this simply is the most efficient solution, mainly because of the clothesline factor. When executed properly you can't score faster with a mechanism that goes above the overpass for a period of time during the score. So how you get the ball off the ground becomes important, but no reason a shooter can't use the same mechanism an arm can.
Yes there will be plenty of arms scoring faster than shooters, but that will be because of execution or techniques. But if done right I can't see how even the best arm (anything that goes above the overpass) could score faster than the best shooter.

[MrForbes]

Yes, but the shooters can probably zip around the track and fetch balls at about the same speed as the arm bots. Also some of the shooters (specifically pneumatic ones) probably need the time it takes to make a lap to recharge the air tanks.

Should be fun to see what interesting ways different alliances can come up with to play the game!

[Jonathan Norris]

Personally the best robots this year will be a combination of both, we will see robots that can knock down, pickup, place, and shoot the ball. I am willing to bet that a couple of the top teams will build a bot that can do all of the above extremely effectively, hey we haven't seen 71, 111, 67, 254, 233, 1114 ect. yet!

[R.C.]

I'm totally with EricH, i would like to see 2 arm robots and a shooter alliance

[SteveGPage]

Personally the best robots this year will be a combination of both, we will see robots that can knock down, pickup, place, and shoot the ball. I am willing to bet that a couple of the top teams will build a bot that can do all of the above extremely effectively, hey we haven't seen 71, 111, 67, 254, 233, 1114 ect. yet!

Team 836 has designed our bot to do just that. All the various components work quite well, and tonight we will start the extensive integration testing to see how effectively they all will work together.

[Michael Corsetto]

I think a third classification should be added to this thread...

Throwers.

:)

[cwood]

just for discussion purposes hat if said shooter were capable of knocking a rather large mentor off his feet from the opposite side of the field, what would be your plan to easily block it. without getting you robot destroyed

[Brandon Holley]

just for discussion purposes hat if said shooter were capable of knocking a rather large mentor off his feet from the opposite side of the field, what would be your plan to easily block it. without getting you robot destroyed


Blocking a ball is a completely legit strategy.....but you better bet the team blocking is taking a risk by attempting to "stuff" you. Doesn't mean they can't do it though.

[StephLee]

Inform me if I am wrong, but by definition, HURDLING is defined in the rules as the trackball ball top being positioned just above the top rail of the overpass, or higher. Therefore, unless shooters shoot from that level (minimum height), they are not considered in the act of hurdling, even though that may be the end result of their shooting the trackball. Therefore, it would seem, blocking the shot is well within acceptable defense. At least, that's my interpretation of what I have read. :) :)

HURDLING: The act of completing a HURDLE. To be considered in the process of HURDLING,
the ROBOT must:
 be in its own HOME STRETCH, and
 be in POSSESSION of a TRACKBALL, and
 be moving toward the OVERPASS and/or elevating the TRACKBALL so that the top of the
TRACKBALL is higher than the LANE DIVIDER.

So a robot that is in its home stretch, in possession of the trackball, and moving toward the overpass, it is in the act of hurdling and therefore still protected from contact to it or its trackball.

[cwood]

Blocking a ball is a completely legit strategy.....but you better bet the team blocking is taking a risk by attempting to "stuff" you. Doesn't mean they can't do it though.

well they could probaly do it once and the ball could leave the robot from above 5 feet so i believe that what ever is used to block the ball will end up dangling from the robot so i believe it will happen once until teams see the results

[Kellen Hill]

Well,

1. Shooters can have mechanisms to knock the ball down. I know my team does and,

2. A hurdle at the end of the game rather than setting it back on the overpass is just as good, you just miss out on a couple points.

I think effective shooters will dominate this years game.

[cwood]

Thank you hill i believe that will be the case as well

[SgtMillhouse648]

I personally feel that a combination of both a shooter and arm are vital to this year's game. Shooters are fast at some things, and absolutely horrible at others etc. placing on top of overpass. Arms are the same way. They both have their pros and cons, and to work to the best of their abilities, must work together to score the maximum number of points. We have an arm this year, but have come up with a way to score more points than the average arm....wait and see.......

[Kellen Hill]

Being able to set the ball up on the overpass gives you 12 points while doing another hurdle and crossing the line gets you 10. Where is the major advantage in 2 more points?

[s_forbes]

Being able to set the ball up on the overpass gives you 12 points while doing another hurdle and crossing the line gets you 10. Where is the major advantage in 2 more points?

Well, four more points, because you could also drive under after you place the ball. (or push the ball under, drive under, and put it up for 6 more points!)

But I think the real advantage to the placing the ball at the end is that you can do it on either overpass (correct me if I'm wrong...). So if you are stuck on the wrong side of the field and need a quick 12 points to win the match, placing the ball up is the way to go.

[Sam N.]

Well,

1. Shooters can have mechanisms to knock the ball down. I know my team does and,

2. A hurdle at the end of the game rather than setting it back on the overpass is just as good, you just miss out on a couple points.

I think effective shooters will dominate this years game.

I disagree,

My team has built a shooter but I think that well-built lifters will provide major competition.

A well-built, fast, and coordinated lifter will be just as powerful as a shooter in my opinion. Some teams have already proved this with their videos they have released.

Sam N.

[Uberbots]

I think effective shooters will dominate this years game.

I wouldnt be so quick to state that if i were you (=
in the end, the only major advantage that a shooter has over a lifter is that they dont need to stop in order to score. However, like lifters, they also have a range of scoring positions. For example, for a lifter to score, it will typically need to be right in front of the overpass before releasing the ball so that it can go over. With a shooter, if it is too close the ball will hit the underside of the overpass, and if it is too far away it might not go over altogether.

[Tim Arnold]

Shooters

Cons:
Cannot Place on Overpass at end
Can be "Blocked" easily
Cannot (on their own) knock down balls off overpass.
Don't be so sure. As others have said, there is no reason that a properly built thrower can't also place on the overpass and knock down balls... and what if the release point is at 5 ft?

Another bot would have an awfully hard time getting in the way to start with, and then the 10lbs + momentum of the ball would be impacting the blocking robot 6ft in the air or so. I smell tipsy robots.

[jacob07]

Who says a shooter robot can't take a ball down and put it back?


If teams were thinking ahead like they should be they should be able to knock the ball down, it wouldn't be that hard to make something to do that....would it?

Also if you were a shooter, wouldn't you have tested the tar outta of it? shouldn't you be able to get yourself in range of the overpass to be able to shoot it and land on the overpass, all it takes is testing and figuring out how far back you would have to be.

Just my two pennies

Jake

[=Martin=Taylor=]

It's always true how you execute your design is the deciding factor as to how successful it will be. However 118 showed how easy it is to make a great launcher. We contemplated copying that when we saw it. It would have been easy to do (the launcher anyway). I'll bet a number of teams did. Why not?
However, all things being equal, this simply is the most efficient solution, mainly because of the clothesline factor. When executed properly you can't score faster with a mechanism that goes above the overpass for a period of time during the score. So how you get the ball off the ground becomes important, but no reason a shooter can't use the same mechanism an arm can.
Yes there will be plenty of arms scoring faster than shooters, but that will be because of execution or techniques. But if done right I can't see how even the best arm (anything that goes above the overpass) could score faster than the best shooter.

Exactly.

One thing I've noticed is that many of the successful "arms" are VERY adept at picking up the balls quickly (rollers: 121, 179, 1902...)
Yet they are slightly slower when it comes to hurdling.

The catapults on the other hand, excel at hurdling, but struggle to pick up the ball.

I believe that in the end the two designs will hurdle equally fast. Catapults will hurdle faster, and arms will pick-up faster. (provided of course that both designs are properly executed)

This is all the result of engineering trade offs...

[jacob07]

Exactly.

One thing I've noticed is that many of the successful "arms" are VERY adept at picking up the balls quickly (rollers: 121, 179, 1902...)
Yet they are slightly slower when it comes to hurdling.

The catapults on the other hand, excel at hurdling, but struggle to pick up the ball.

I believe that in the end the two designs will hurdle equally fast. Catapults will hurdle faster, and arms will pick-up faster. (provided of course that both designs are properly executed)

This is all the result of engineering trade offs...

couldn't you theoretically combine both methods, have a arm lift the ball to the launcher?

[MrForbes]

We have an "arm" that picks up the ball just fine and loads it on the launcher.

It turned out that it is much easier than we thought it would be.

[Kellen Hill]

I disagree,

My team has built a shooter but I think that well-built lifters will provide major competition.

Sam N.

I agree with you, and think that they will provide lots of competition. It is just my opinion that I think "effective" shooters will dominate the game.

[jacob07]

We have an "arm" that picks up the ball just fine and loads it on the launcher.

It turned out that it is much easier than we thought it would be.

IMO those kinds of robots are going to be the winners in the end

[hipsterjr]

Our shooter has a fork on the front ( similar to 1726) and we can get the ball on the run. I have actually found it easier than it was to pick up ringer with our arm last year. Many less capable arms will requier more aiming to pick the ball up just right. I think where the shooters will gain the advantage is precision. Shooters can be a little (for lack of a better word) sloppier can still score. I would even dare to say easier to build and upkeep.

[Spartan151]

I'll tell you from firsthand experience that even though arms are a good idea, shooters are going to make the points. Our problem that we've had since week 3 (When we started on the arm) is that....well, the arm motors can't lift the combined weight of the arm, the claw, and the ball. So, we tried a lighter arm. Still couldn't lift the combined weight. Given the fact that our team doesn't have much to work with, we changed strategy.

Shooters have their advantages, and so do arms. They both have their cons. Just depends on what you want to do, really.

[Joe Matt]

Shooters all the way. Yes arms can get the balls on top if need be, but frankly people, the balls can easily be knocked off the overpass almost as easily as they were put up there. It's similar to 2003, it was too easy to remove the big points.

[t-raum]

A shooter I think is the best way to go even during end game. As long as you have a device that can knock the ball off the overpass at the end. The shooter can hurdle and then knock te opponents ball off the overpass to create a 22 point gain for the alliance who can do this. If a team can pull this off end game would be very interesting.

[Captain Sugar]

our shooter is almost like an arm in its attributes. it can pick up the balls really easily, using a set of rings on the front. however, when it shoots, the pneumatics contraption pushes out too far and actually pushes the robot off the ground, so we can't shoot on the go. it shoots the ball really far, though.

[Bomberofdoom]

What about an arm that can kind of act like a shooter?

Our robot has a claw system that grabs the ball from the floor and then the arm goes up about 70-80 degrees while the claws themselves rotate to be horizontal. We can drop the ball onto the overpass but we're not sure it can go over the overpass easly.
That's why we're trying to implment a function in the programming area that will bring the arm back 135 degrees(!) and once the robot is in position and the button has been pressed, the claws will rotate at full speed and will release the ball in the midst of the whole action which will cause the ball to fly over the overpass.

Now, I'd call that a thrower, which can count as a combination of an arm and a shooter.

pros?
- Doesn't have to position itself specificly in order to make the ball pass the overpass.
- Cannot be blocked.
- Can put the ball on the overpass.
(- can catch the ball on the run.) - to be tested.

Cons?
- it can take about 6-5 seondes to get the arm and claws in shooting position, might be some disadvantage.


There's probablly more that I just can't point them out 'cause I haven't went through them yet...

Your opinions about this?

[ALIBI]

Shooters have the advantage. Most arm bots will have to stop moving before they can hurdle the trackball and they are limited as to where they must be in the home zone (close to the overpass) when they lift and hurdle the trackball. A good shooter will be able to hurdle the trackball on the fly from at least a third of the floor space in the home zone. Several people have talked about a shooter not being able to pick up a trackball as fast as an arm bot. I believe that you will have shooters that can pick up a trackball just as fast as any arm bot out there. Placing the trackball is way over rated. Given the speed of a shooter vs an arm bot that places. The shooter should be easily able to get more hurdles than an arm bot to make up for a single 12 point placement. Also, you will never see a shooter get clothes lined by the overpass.

IMPEDING: Preventing or obstructing an opposing ROBOT’S ability to proceed around the TRACK in the direction of traffic.

As for blocking a shooter, all a shooter has to do is head directly towards the blocker, just before it gets to the blocker, veer left or right and launch, if the blocker moves to get back in front of the shooter, the shooter just earned negative points for impeading.

[Eye-gor]

Here are some pros and cons I see of both:

Shooters

Pros:
Quick release
Can hurdle "on the run"

Cons:
Cannot Place on Overpass at end
Can be "Blocked" easily
Cannot (on their own) knock down balls off overpass

Arm lifters

Pros:
Can knock balls off overpass
Can place on overpass at end of game
Cannot be "Blocked" while hurdling

Cons:
Slightly slower than shooters
Possible High Center of Gravity

But you haven't gone through all the possibilities. the hardest part of this year's game (design-wise) was choosing a direction to take, whether we'd catapult the ball, or use an arm...or a combination of both.

[jimbot]

You can't really block the ball. unless Im mistaken there is a rule prevnting oppossing robots to be over 5 feet in your home stretch.
As for shooter vs. arm, please watch lower video. If 118 can remove over head ball, then they will be amazing using that SHOOTER!

http://ca.youtube.com/watch?v=CAJBC-DDL9w:ahh: :ahh: :ahh: :ahh:

[EricH]

You can't really block the ball. unless Im mistaken there is a rule prevnting oppossing robots to be over 5 feet in your home stretch.You are mistaken. Please read the current edition of Section 7 and Updates 1 and 2.

There is now no height restriction, other than the physical limits of the Overpass.

[hipsterjr]

I think the biggest con with shooters will be air usage (assuming most are using pneumatics). Ours has 2x 2" and 2x 1.5" by 10" cylinders. After a launch our air tanks loss a lot of air, but can still operate at 50+ psi. 1726 has has provided some great advice on air conservation in a couple threads. As long as teams can keep air in their tanks (and a little in the cylinders;) ) Shooters will dominate the field.

side note: even if some teams have air problems, strategy could compensate for their recharge time.

[XXShadowXX]

I personally like the arm bot for the reason that our robot was designed with plug and play in mind, we wanted to in case of mistake or error be able to remove that whole 'arm' assembly, and replace that with a bumper/herding device. To answer your next question, yes we are that far under wieght, 835 holes pre cut, 95 lbs W00t!

[Doug Leppard]

In the scrimmages, has anyone seen how shooters did especially as related to arms?

[Chris]

In my humble opinion the entire game is ball acquisition...it doesn't matter what your method of getting the ball over the overpass is....The teams that are best at grabbing it quickly will be the best teams hands down...

[waialua359]

I agree with this. Effectively grabbing the ball quickly and moving around the field to get in position to score is important.
The one thing I keep hearing from all these threads is that, if you lose autonomous by 15-20+ points, its too hard to overcome if both alliances can fairly hurdle, herd, and do laps.
I'm not so sure if even the best hurdler on an alliance can overcome 20+ points, when everyone else can score, there will be traffic, and only 2 balls per alliance.

[martin417]

A well designed shooter (IMHO) can outscore most arm designs. It should be able to:

Acquire quickly.
Shoot on the run.
Avoid legal blocking maneuvers.
Place the ball on the overpass.

I know of at least one such arm.


http://www.youtube.com/watch?v=QeQSGmFnKAE

One big problem with arms is the CG. While lifting the 8+ pound ball 6 1/2 feet off the floor, the CG is very high. I saw several arm bots go turtle at the scrimmages.

[PhilBot]

Who says a shooter robot can't take a ball down and put it back?

You mean like this: http://www.youtube.com/watch?v=T5d34yZrSH0

[waialua359]

A well designed shooter (IMHO) can outscore most arm designs. It should be able to:

Acquire quickly.
Shoot on the run.
Avoid legal blocking maneuvers.
Place the ball on the overpass.

I know of at least one such arm.


http://www.youtube.com/watch?v=QeQSGmFnKAE

One big problem with arms is the CG. While lifting the 8+ pound ball 6 1/2 feet off the floor, the CG is very high. I saw several arm bots go turtle at the scrimmages.

I think it depends on the bot. I'm pretty sure some bots will be very stable while lifting and scoring. We throttled full speed from dead rest with our ball straight up in the air (and vice versa), and our robot does not tip at all.
I'd be more scared of a shooter launching a ball dead square on our bot, although I think we would survive. Some of the bots that I have seen have ball grabbers that look so flimsy like they'll break with a little impact. :eek: :eek:

[Donut]

In the scrimmages, has anyone seen how shooters did especially as related to arms?

I can't say for an actual competition scrimmage, but at the scrimmage our team attended (which was really just an endless practice session on a full sized field) the 2 shooter bots totaled well over 20 hurdles, while the 5 or 6 arm bots totaled 1 or 2 hurdles. This might be slightly deceiving though as the shooters are extremely successful veteran teams (39 & 842) while most of the arms were fairly new teams and not yet finished with construction.

A well designed shooter (IMHO) can outscore most arm designs. It should be able to:

Acquire quickly.
Shoot on the run.
Avoid legal blocking maneuvers.
Place the ball on the overpass.

The one humongous disadvantage I see against shooter bots is that they don't get the courtesy of protection during hurdling really, as there is no way to judge when they are attempting to hurdle. Standard defensive maneuvers of parking in front of them won't work, but instead it's very easy to push them from behind and not give them a chance to slow down to a speed they want to shoot at, and simply push them past the line so they must go around the field again to hurdle. I also see stealing a ball that has been launched as easier to do than stealing a ball that is just dropped over the overpass.

Honestly I think shooters are a bit easier to defend than arms, so although they may be able to score faster in theory, I think more intense defensive strategies against them will balance out their success.

[Squirrel Lord]

The one humongous disadvantage I see against shooter bots is that they don't get the courtesy of protection during hurdling really, as there is no way to judge when they are attempting to hurdle. Standard defensive maneuvers of parking in front of them won't work, but instead it's very easy to push them from behind and not give them a chance to slow down to a speed they want to shoot at, and simply push them past the line so they must go around the field again to hurdle. I also see stealing a ball that has been launched as easier to do than stealing a ball that is just dropped over the overpass.


HURDLING: The act of completing a HURDLE. To be considered in the process of HURDLING,
the ROBOT must:
 be in its own HOME STRETCH, and
 be in POSSESSION of a TRACKBALL, and
 be moving toward the OVERPASS and/or elevating the TRACKBALL so that the top of the
TRACKBALL is higher than the LANE DIVIDER.


Please read the thread before posting, this has been posted many times.

[EricH]

Please read the thread before posting, this has been posted many times.He has a point. If the shooter stops and isn't raising the trackball, it can be hit. It won't be protected until the ball starts moving. Whereas, an arm/lift robot has protection until it releases above the overpass (it would be either raising or moving, or both). Just something to think about.

By the way, we are almost to the point where one side or the other will outperform the other. On the whole, they seem pretty even. There are exceptional arm robots and mediocre ones. The same for shooters. We will see what happens with exceptional arm vs. exceptional shooter, mediocre arm vs. mediocre shooter, and one mediocre and one exceptional (both ways).

Prediction: Those robots whose hurdling mechanism is... ummm...shall we say... less than mediocre will quickly find themselves running a lot of laps.

[=Martin=Taylor=]

couldn't you theoretically combine both methods, have a arm lift the ball to the launcher?

Yes you could. But NON-theoretically speaking you probably would have to sacrifce some pick-up speed for some hurdling speed. :)

Trade-offs trade-offs!

[AdamHeard]

I'll tell you from firsthand experience that even though arms are a good idea, shooters are going to make the points. Our problem that we've had since week 3 (When we started on the arm) is that....well, the arm motors can't lift the combined weight of the arm, the claw, and the ball. So, we tried a lighter arm. Still couldn't lift the combined weight. Given the fact that our team doesn't have much to work with, we changed strategy.

Shooters have their advantages, and so do arms. They both have their cons. Just depends on what you want to do, really.

That isn't a flaw against arms at all...

973 has an arm, and at only 2/3 power it easily lifted a 130 pound freshmen.

[StephLee]

The one humongous disadvantage I see against shooter bots is that they don't get the courtesy of protection during hurdling really, as there is no way to judge when they are attempting to hurdle. Standard defensive maneuvers of parking in front of them won't work, but instead it's very easy to push them from behind and not give them a chance to slow down to a speed they want to shoot at, and simply push them past the line so they must go around the field again to hurdle. I also see stealing a ball that has been launched as easier to do than stealing a ball that is just dropped over the overpass.

Honestly I think shooters are a bit easier to defend than arms, so although they may be able to score faster in theory, I think more intense defensive strategies against them will balance out their success.

I would agree that it might be easier to park in front of a shooter...unless it can easily shoot over you. Or into you, if it has no reservations about knocking you over. Also, who says the shooter has to stop or even slow down significantly? And, with an increase of shooting range, it will become increasingly difficult to defend a shooter as you'd have to try to stay within the defensive restrictions for most of the home stretch. Some shooters will not have specific "sweet spots" they must shoot at, or speeds at which they must shoot to be successful, or large restrictions about what kind of space in front of them when they're shooting.

Also...pushing from behind won't work as well on a robot that can get out from in front of you before you touch them. :)

As a general warning, I would ask that teams with large arms or shields who intend on using them to block a shooter take the time to watch that team hurdle a few times before deciding to risk their robot. You could be submitting your arm to quite a large amount of force. I would personally hate to be responsible for breaking, tipping, or otherwise damaging an unwitting opponent, but my team will not hesitate to shoot through a block.

[Donut]

Also...pushing from behind won't work as well on a robot that can get out from in front of you before you touch them. :

I was referring more to herding only robots (or lap only bots, but not tiny ones with no pushing power) playing the defense, and I assume that most of the herder only bots will be able to outrun their heavier shooter/lifter counterparts. If a herder isn't built for speed I'm not sure what the point of making it was.

I definitely won't advocate trying to block a ball shot from a shooter though. I know I don't want the top of my robot snapped off or lying on the ground.

[Jeff Waegelin]

In my humble opinion the entire game is ball acquisition...it doesn't matter what your method of getting the ball over the overpass is....The teams that are best at grabbing it quickly will be the best teams hands down...

I agree with this 100%. It doesn't matter how quickly you can hurdle if you have to chase the trackball all over the field. Until you have the ball in your posession, you can't do anything with it.

[JAZAD1]

I belive that the shooter is more efective it the teams that have it have incorperated a system that can also knock the balls off of the overpass because you can always derack a ball and it takes more time to place than hurdle.:cool:

[David Brinza]

In my humble opinion the entire game is ball acquisition...it doesn't matter what your method of getting the ball over the overpass is....The teams that are best at grabbing it quickly will be the best teams hands down...That was Team 980's conclusion - though some of us (including me) liked the idea of "extreme launching" of the balls.

The robot needs to be both agile and powerful to get in position to grab a Trackball. Once in position, a strong and reliable gripper is needed to secure the ball. Once the trackball is in possession it can be fed to a good launcher or just pushed over the overpass. Possession is the key...

[hipsterjr]

The problem with some arms I have seen is their ball graber. They have to line up just right to pick up the ball. Most launchers (including ours) have forks that pivoit back to hold the ball until launch. From testing, we have been able to pick up the ball without stoping (but we did slow down just a little:cool: ).

[Éowyn]

In my humble opinion the entire game is ball acquisition...it doesn't matter what your method of getting the ball over the overpass is....The teams that are best at grabbing it quickly will be the best teams hands down...

You make a good point. Our pick-up mechanism can suck in the ball from angles varying up to about 40 degrees to the the side, although a straight shot is always best. If we have a straight-ish shot, we don't need to slow down at all.

I would agree that it might be easier to park in front of a shooter...unless it can easily shoot over you. Or into you, if it has no reservations about knocking you over. Also, who says the shooter has to stop or even slow down significantly? And, with an increase of shooting range, it will become increasingly difficult to defend a shooter as you'd have to try to stay within the defensive restrictions for most of the home stretch. Some shooters will not have specific "sweet spots" they must shoot at, or speeds at which they must shoot to be successful, or large restrictions about what kind of space in front of them when they're shooting.

Also...pushing from behind won't work as well on a robot that can get out from in front of you before you touch them. :)

As a general warning, I would ask that teams with large arms or shields who intend on using them to block a shooter take the time to watch that team hurdle a few times before deciding to risk their robot. You could be submitting your arm to quite a large amount of force. I would personally hate to be responsible for breaking, tipping, or otherwise damaging an unwitting opponent, but my team will not hesitate to shoot through a block.

I completely agree with everything you just said.

[Brandon Holley]

Please read the thread before posting, this has been posted many times.

Your not a moderator... if it is your opinion it is a redundant post then please tell the moderators, there job here is to, yes, moderate...


from the scrimmage in suffield I made a couple of conclusions of both shooters and arms.

Arms:
Very open to damage by the overpass
Tended to be slower
Tended to be more tippy

Shooters:
Far fewer shooters overall
Tended to be faster (when they worked)
Tended to be less tippy

Overall though (with the exception of the gaelhawks) I have to say they seemed to be working about the same.

What won and lost was the ability to grab the ball on the move with little effort lining it up.

[jfc358]

Summary so far:

Arms:

open to damage near overpass
tend to be slower
tend to be tippy
more of an entanglement risk with other robots
ball alignment during pickup can be too critical and slow
can play a "deny the ball" strategy by herding opponents track ball
harder to block before act of hurtling
can block from behind overpass
can easily place the ball on the overpass
can easily remove trackball from overpass
can be in possession of track ball at end of hybrid



Shooters:

can score faster and on the run
usually faster on the track due to lower CG
seem to be fewer shooters than arms
tend to be less tippy
greater track ball pick up range and speed
many not good at herding for defensive purposes [opponents ball]
can not possess track ball immediately after hybrid period
many less effective at removing trackball from overpass
less effective at placing track ball on overpass


but again then, who says an arm can't shoot!!! ;)

http://youtube.com/watch?v=N1BZAsH-RYA

[lasereyes]

Our team uses an arm to get the ball up and uses a pneumatic 'poker' to actually hurdle the ball.

Our main problem is not getting the arm caught on the overpass, which isn't really a problem in driver-controlled mode, but is a problem for autonomous. We've also had some minor issues with tipping over (only under extreme circumstances), but since our robot only weighs 88 lbs, we are planning on adding at least 20 lbs of ballast.

[pafwl]

I have read pretty much all of the post on this thread and I am impressed with many of the arguments

Just so you know where I am comming from our robot is a shooter. It however does not use pnematics to "shoot" "launch" the ball. Go to www.frc272.com and maybe you can figure out how we do it. Look under "We are LC" "2008 season". Anyway our robot also employes an alternate aparatus that can effectivelly remove the ball from the "monkey bars" "rack" whatever it is you call it.

However I am not at all saying this is the way to do it. We just like that fact that we can move on the fly and shoot. Also since we can remove the ball from the rack using an alternate aparatus we like it. Anyway

I have been lookin at a whole lot of video of other robots and I believe it just comes down to speed, quickness of picking up the ball and if you are a lifter doing it as fast as possible. If you have all of that I do not care how you do it you are getting it done fast and often and probably can keep up with anyone.

I also read some threads about it is easy to block a "shooter" "launcher" and while I would agree with that. I would recommend to teams you avoid it. Just as an example I had one of those moments and walked in front of our completed robot just as it fired. That ball almost took my head off. In retrospect it was very funny but the forces of that fire took a 210 pound man and put him on the floor. I just think if a lifter decided to get in the way and took a shoot either the robot may sustain fatal damage our it might be out for the count if you catch my drift.

Any who I think in the end if you built a great robot no matter how it scores if it is quick, accurate and efficient. Oh and a killer autonomous/hybrid would not hurt it really wont matter.

[deshirider430]

what about 612's shooter arm lifter? http://youtube.com/watch?v=VbGBxKjMlh0 :rolleyes:

In our early discussions we wanted to be able to; knock the ball off, pick up the ball quickly, shoot the ball over the overpass without stopping, and place the ball at the end. Guess we ended up doing all of them.

[TheOtherGuy]

I'm still waiting to see a robot pull a "BOUNCE-CATCH" maneuver. By putting enough backspin on the ball when launched, it could, potentially, bounce into a standstill so the robot can catch it again.

I know this is highly improbable with the crowded field and such, but it would still be the neatest and most efficient thing ever!

http://img254.imageshack.us/img254/4228/bouncecatchin2.gif

[Scott358]

I haven't seen anything with back spin, but I did see a video of a bot who drives under the overpass in autonoumous, hits the ball up and forward, drives forward and catches it off the overpass. I don't know how relaible it is, but in the video it was pretty cool.

[MrForbes]

oh, like this?

http://www.youtube.com/watch?v=UwfT5V6fYRQ

:)

[Zuhaib Ali]

In my opinion, a combination of a roller claw and shooter will out score a robot with a arm or regular shooter. ;)

[Scott358]

oh, like this?

http://www.youtube.com/watch?v=UwfT5V6fYRQ

:)


That's not the one I was referring to, but that makes at least 2 that do it!

[TheOtherGuy]

So... anyone's mind changed? Are the results from the 1st week of regionals surprising to anyone, of is there anything you weren't expecting?

Any insights that pertain to this thread regarding that 1st week of regionals?

[hipsterjr]

In the NJ finials there were two shooters ( can't remember #'s). One had some problems. But the other one blew the TB and the arm bots away. Doesn't really change my mind, shooters rule!

[T3_1565]

shooters are really good. Yet I saw two really good arm bots and 1114 is both a shooter and an arm (more shooter than arm yes, but still).

But overall I'm impressed with all the designs so far.. these regional was awesome!!!!

[Diriye]

After this first week, it seems as though the shooters were clearly better than the arm-bots. When you matched up the best shooters vs. the best arm-bots, the shooters were much more efficient at hurdling, and if they had a decent pickup system, they were usually one of the best teams there (i.e. 1625, 1114)*. Having said that, there were many more arm-bots or "looks-like-an-arm" bots at the regionals, and the average arm-bots were usually better than the average shooters, as shooting the trackball seems to be much harder than using an arm.

*Yes, I'm quite aware that there are very few, if any, teams like 1625 or 1114.

P.S. Taking 20 seconds to pick up a trackball tends to screw you over...

[ALIBI]

I would add to your comments (Diriye) that a shooter with a simple bar to knock down a trackball from underneath was much faster than an arm bot that had to raise its' arm above the crossover to knock down a trackball.

[EricH]

After this first week, it seems as though the shooters were clearly better than the arm-bots. When you matched up the best shooters vs. the best arm-bots, the shooters were much more efficient at hurdling, and if they had a decent pickup system, they were usually one of the best teams there (i.e. 1625, 1114)*. Having said that, there were many more arm-bots or "looks-like-an-arm" bots at the regionals, and the average arm-bots were usually better than the average shooters, as shooting the trackball seems to be much harder than using an arm.

*Yes, I'm quite aware that there are very few, if any, teams like 1625 or 1114.

P.S. Taking 20 seconds to pick up a trackball tends to screw you over...Are you also aware that 1625 and 1114 could both fit into either the arm category or the shooter category?

I think the robots that dominate will be a combination of arm and shooter. Call it an "arm-mounted shooter", if you will. Varying angle for different shots, quick pickup and raising to fire, and higher shooter distinguish this class of robots.

They also effectively end the "arm vs. shooter" debate by having both.

[Psychoflood]

Hipster,

The finalists you were referring to from the NJ regional are Team 25, Raider Robotics, and Team 103, Cybersonics. They were the two shooters that won the finals in NJ. IMO, it would seem shooters are better than arm or "looks-like-an-arm-bots" because they're just faster, although some of them such as 25 sometimes seemed to have problems with ball possession, and 103 missed quite a lot (hitting bars, shooter deployed from a crash, etc.) However, both teams did a great job and congratulations!

-John

[s_forbes]

Are you also aware that 1625 and 1114 could both fit into either the arm category or the shooter category?

I think the robots that dominate will be a combination of arm and shooter. Call it an "arm-mounted shooter", if you will. Varying angle for different shots, quick pickup and raising to fire, and higher shooter distinguish this class of robots.

They also effectively end the "arm vs. shooter" debate by having both.

I think it depends on your definition of an arm bot and a shooter bot. To me it seems that any robot that is able to 'toss' the ball into the air without reaching higher than the overpass qualifies as a shooter robot. The debates revolving around arm/shooter robots were mostly based on the fact that 'arm robots' can reach above the overpass to remove/place balls.

So, in my opinion, 1114 and 1625 were not arm bots, just shooter robots. Their intake systems are what made them perform so well.

[waialua359]

Based on the Oregon regional, arms bots were the winning alliance.:D

[jfc358]

Our robot, team 358, is clearly an arm robot, but since we can shoot from at least 8 feet from the overpass while on the move, it posseses many of the advantages of a shooter. I am sure there are other similar designs out there. So framing the debate as arm vs. shooter ignores the existence of these hybrid bots. In the coming weeks we will see how this plays out.

http://www.youtube.com/watch?v=N1BZAsH-RYA

[GaryVoshol]

My opinion is that Great Shooters are better than Great Armbots, but perhaps only marginally so. But when you get into the Good and Average categories, the benefit becomes less. I saw several robots that I would consider Good Shooters and at least one Great Shooter miss the hurdle, either shooting too soon, too late, or at an angle. They had to make another complete lap to try again - while an Armbot managed to score. I don't think this should be a "Tastes Great" / "Less Filling" kind of thing. Actually, maybe it really is that kind of thing. The whole point of the beer commercial was that both things were true, and why should they be spending time arguing about it. Both Armbots and Shooters are good and have their advantages - can we leave it at that?

[Scott Carpman]

That's not the one I was referring to, but that makes at least 2 that do it!

I believe you are then referring to us (http://youtube.com/watch?v=zD0yMN21WN8).

[Drwurm]

Due to the incredible importance of the endgame, we will see arm/lift bots in the Einstein finals. Shooters can do some endgame strategies, but nowhere near as well as arms or lifts can.

[waialua359]

I agree that at Einstein, the end of match strategies and play will determine matches. Great teams will constantly counter each other with great hurdling and autonomous play. A possible 24-0 score difference due to end of match placing of trackballs is a lot of points.
Those things didnt seem to matter too much in many matches during week 1 because quite a bit of matches were won during autonomous play, penalties negated bonus scores, and matches were not close.

[Greek Assassin]

Due to the incredible importance of the endgame,

I need to stop you right there. Now lets say, to take the worst case scenario for the shooter, that its a tie score, that the arm will place 100% of the time and the shooter is incapable of placement. There are 10 seconds left. An arm bot on one alliance begins to place, while the shooter on the other alliance is moving to hurdle. Whats to stop the shooter from hurdling and, since it doesn't need to stop while doing so, continuing around the track and knocking the arm bot's trackball off the overpass. Since we are assuming the worst case scenario for the shooter, lets say that the the ball rolls off in the direction of traffic, and is therefor counted as a hurdle for the arm bot, we still have a tie score. Now factor in that if you take an arm bot and a shooter of equal degrees of efficiency, the shooter will hurdle at least one more time in the match than the arm, just the fact that shooters don't need to stop assures that. This means that in most scenarios, it wont be a tie game with ten seconds left, the shooter will have the lead, and the ability to match or negate any bonus points by the other alliance.

[Drwurm]

Endgame creates a potential 24 point difference in your score if done well enough. The game does not have to be a tie, or even close to one for the endgame to be important. The idea with endgame is that you place your balls close enough to the end that another team does not have time to come back around and knock them off. I believe the ideal alliance will be 2 shooters and one arm/lift.

[Greek Assassin]

Actually if the shooters cant place they can still hurdle. Two placements and two hurdles only have an 4 point difference, because an arm cant place and then cross the finish line if it places at the last second, and a shooters superior speed will make up for those 4 points.

[T3_1565]

Actually if the shooters cant place they can still hurdle. Two placements and two hurdles only have an 4 point difference, because an arm cant place and then cross the finish line if it places at the last second, and a shooters superior speed will make up for those 4 points.

..Most arm bots could keep up (speed wise) with the shooters, and good armbots had very little time wasted to drop there arm (Killer Bees, Wildstang, both of which hurdled just as fast as 1114) and you saw times where the placements won the match against shooters (Killer Bees against Simbotics the first time, Wildstang against the rookie shooter 23xx?? 2358 maybe..)

[Laaba 80]

..Most arm bots could keep up (speed wise) with the shooters, and good armbots had very little time wasted to drop there arm (Killer Bees, Wildstang, both of which hurdled just as fast as 1114) and you saw times where the placements won the match against shooters (Killer Bees against Simbotics the first time, Wildstang against the rookie shooter 23xx?? 2358 maybe..)

They might have kept up with them a few times, but most of what I saw 1114 blew them away. From what I saw today, the most hurdles Wildstang got was 3, I saw 1114 get 5-7. I also thought that the finals were a pretty good example of arm vs shooter and shooter won. I do think you could compare killer bees with a shooter however. their arm is very effective, falling down after they hurdle so they dont need to wait. I thikn that may be the best arm bot we see this year.
Joey

[Akash Rastogi]

This is our end effector. Its 3 rollers. The two fiberglass folding arms that are sticking out at the bottom have been removed. Works like a charm and the top part of the rollers is used to push off balls. It was good enough for us to be undefeated in elimination rounds (until we faced 103 in the finals that is :p ). But overall, I love this thing. I would make it into a shooter though if we could do it all over again:P(j/k)

[ZakuAce]

I'm totally with EricH, i would like to see 2 arm robots and a shooter alliance

I agree. In fact, if everyone built shooter bots, the game would suck. Maybe shooter bots score the most points, but don't downplay what arm bots or lap bots can do. Diversity is what makes the competition great. Having a shooter to move quick, score points while one armbot is placing. The other arm bot moves to the other side to grab the ball as soon as the first bot hurdles, could go really quick if done right. Then at the end game both arm bots place the trackballs, man that would be coooooollll.