Goal Grabbers
 

Just out curiousity, if your team is aiming to grab goals...

- How are you planning to do it?
- What type of mechanism are you using?
- Is your team's robot going to enable the robot to grap one or two goals?

Scorpion

We're a rookie team

Our goal is to try to grab one goal..and move it :)

We'll be very happy if we can get it to move

We're grabbing two goals from the sides OR one goal from the back. We're not %100 sure about all of the mechanisms....

we are planing on grabing one goal and loading balls

Top Secret But I'll Tell You This....
Goals are involved.

few general ways...
 

A few general ways you can grab the goals.

First, if you are doing one goal, you would probably grab the goal in front when your robot rush toward the goals. Or you can do it on your side, although you will need to compensate for that one goal dragging one side of your drive train.

Second, if you want to grab two goals, you can either do one on each side, or one front one back, or have a telescoping/very long arm extend past the first goal to grab a second goal.
Grabbing two goals probably need some sort of arms on your side extending out to reach for both goal at once to do it fast, or else you you will have to aim to grab the second goal from some other robot.

Grabbing three goals... you can either extend three long arms out toward all three goals, or you will have a really tough time trying to get a goal or two from opponents... If you are lucky enough to get all three goals, then you can hold them around your robot, and basically push forward with a strong drive train, because the opponents will forget everything else and try to stop you.

So that's some of the general position you want your robot grabbing the goals. As for the actual mechanism, you want to design something that will easily slide in between the poles, and lock on really fast. Design some sort of gate latch so that the physics of you mechanism likes to hold onto the pole(s). They can be grippers, hooks... etc. Just try to avoid having to use power to keep the goal(s) in your procession.

You also want to design that mechanism so your driver don't have to point your robot too accurately to get the pole(s)

You can just grab one pole per goal, or you can grab two pole for a solid connection between your robot and the goal, so when your robot is moving around, the goal will always stay the same relative to your robot.

Also, depends if you want more traction or not, you can lift up the goals slightly to add more weight onto your robot.

Two goals, one front, one back

Think about whaling.

We will harpon the whale. We are from MA. close to BEDFORD MA.
The whaling town.

grab the whale and hang on.


3 will be fun :D

you need to be flexable, if not things will break.

3 goals huh????
 

Ok I have to admit that I did have a great idea to grab 3 goals that would work (theoretically).

BUT, at our first meeting I came to the realization, assisted by a team mate, that grabbing three goals would be a very Stoooopid idea.

Sure it will score a ton of points if you can sucessfully pull it off but, In order to get a great amount of Qualifying Point's your enemy has to have points on the board. The most ideal situation would be a win by one point! You win by getting the most points in the match and you get the most QP's out of the match that you can.

My 2 cents!:D

Re: 3 goals huh????
 

You'd be right IF life ended with the seeding round. The way I see it: If you can reliably grab and control goals, you may not make it into the finals on your own, but you'd make a fantastic alliance partner for someone.

(Understand, I'm not saying I was able to convince my team that this is the tack we should take -- it's just another option (should anyone still be designing their robots.)

Do keep in mind that, just because you can control all of the goals, doesn't mean that you must score them all for your own alliance. A three goal controlling robot could score two in its own zone and one in the opponent's zone, or rotate depending on which goals held balls.

This is an answer mostly for the rookies who are trying to move one goal. It takes about 30 lbs of pull or push to move a goal.
If you build a simple robot using the FP motors you will have trouble moving the goal from a standing start. i.e. if you plan to drive up to the goal, stop, clamp on, pull it back, stop, fill with balls, push back etc. The reason has to do with the torque vs speed curve of the FP motor drive system. If you make the the robot powerful enough to do this it will be so slow, it won't be able to finish in time. If you plan to grab a goal from the side, a two wheel design robot will be able to spin the goal in a circle but
not get to move in a straight line. - The reason we know this is we used a two motor prototype to test the hypothesis.


Instead of a standing start, you might figure out a way to get up a 'head of steam' and hit and push the goal. If say your robot weighs 130 and the goal 180 - you get the robot up to 5mph, slam into the goal and then push it at about 2mph into the scoring region. You then could back up and try for another goal.

As a rookie team - concentrate on how you can help your alliance.
You help your alliance by scoring points. You score points by being able to move, push, pull, possibly lift and drop balls. If you can score more than 10 points, you will help your alliance. If you
can only score ten or less, you won't be much help.

Now as to our tactics for this year ..... We are not ready to say,
other then it involves goal(s?), balls, robots, our allies and our opponents.

Re: 3 goals huh????
 

Grabbing and moving three goals would be very doable, as long as there were no robots out there trying to prevent your do so. If a robot has control of three goals, though, there are likely to be two robots of the opposing alliance working very hard to move the goals, and your robot, where they want them.

But if two robots are trying to get the robot with all three goals stopped....what happens with the last robot....

FRee sailing for them


:D :D :D

The last robot may well be helping the robot with the three goals try to move the goals to and/or hold them in the desired location. This is going to be an interesting game.

(edit to fix typo)

We would only grab three goals only in the finals not in the seedings.





The best score would be a tie and you having the tie breaker.

I see a lot of teams are going for more than 1 goal... Let's think about it for a second. The way I see it , pulling more than one goal is extremely difficult. Your robot max weight is 130lbs.. which is equivelant to one goal. Let's say you are pulling one goal (130lbs) and another robot is pulling in the opposite direction (all together = 260lbs) You'd be lucky if you can pull that. Now if you are going for 2 goals and then you get another robot to fight for them in the opposite direction you are gonna end up pulling 390 lbs and so on, which I think is insane. The situations can be different but you see my idea.

But, once again, thats just my thought...

It's really not insane at all. We did some calculations as to how many pounds it takes to start a goal *just the initial strength* and are devoting a lot to being able to push those two goals and anything that even tries to push us.

We've worked on finding out how many square inches of surface contact with the materials we're using it takes to keep from slipping with pushing both goals, with our weight, and against a robot of our exact strength. Lets just put it this way, when we go into "push mode," we'll be a beast to contend with.

Anyways, teams that decide to do this type of thing and figure out how to do it, are just trying to plan for anything. We're trying to be prepaired for any crappy situation like *god forbid* a no show or at least a disabled robot.

Everybody has their reasons.

The CLAW
 

I will unlease our beast near or after the shipdate!!! :D

The nonbeliever.

Go back to 1999 when there was a puck. Robot pushing and pulling at the same time. with robots on top of this puck.

done very easly with only two motors just think what is going to happen this year.

We will be grabbing something goal-ish using some sort of grabber that will be made using at least some metal and may or may not be attached to our robot, and then we might possibly move while connected to a goal. I would say more, but

We had to reduce the pressure to our grabbers because we kept crushing the steel pipes :D
All kidding aside, our goal grabbers will be AWESOME

Wayne Doenges

Titanium
 

Oh yeah???? Our goal grippers are made of titanium!!! Just kidding. We used something stronger than titanium its called aluminum!!!! hehe

Even if you had 3 goal grippers YOU will never be able to get 3 goals.

Unless the other team's robots dont have wheels lol

We won't be grabbing any goals, or touching any balls (intentionally).

Regards,
Scott358

I think we have the same idea as you do, have you considered how you are going to disengage from the goal, incase an oppent is stronger than you, and decides to drag you with the goal?

Weight limits suck! lol

Our robot is about 50% done and we are alread expecting to turn it into swiss cheese by the time we are done!

But it will be an awesome bot by the time we are finished, which is way ahead of schedule compared to where we were last year! (knock on wood):D