block thrown ball
 

you come around corner. other team is in the act of hurdling. do you race in front of him and risk your arm,forklift or whatever your using to block the throw? just another defence maybe.

Re: block thrown ball
 

Without going over 6 feet?

Re: block thrown ball
 

You'd have to stay under 6 feet as they said, avoid impeding traffic, and there is the question why risk losing a scoring ability by tossing you manipulator in front of a 10lb flying object.

Re: block thrown ball
 

you would have to be on other side of their home rack

Re: block thrown ball
 

And as of Update #1, it could be either side of the overpass.

Re: block thrown ball
 

That's no longer an issue.

Re: block thrown ball
 

After yesterday's team update, looks like its now legal to do that. I can see teams doing it to- It reminds me of 2 years back in 'Aim High,' where robots would get in the way of other bots trying to score in the higher goal. Seems to me like the same stradegy.

Re: block thrown ball
 

We've done the numbers, and it appears very difficult to "throw" the ball over the hurdle, nevermind controlling it on the other side.

Any throwing system will have to be very close the ground to prevent the bot from tipping. In additional, a simple potential energy to kinetic energy computation tells you that you have to hit one of these balls VERY hard to get them to move. 220 lbs of force applied over a 6 inch distance with a 2" bore 6 inch stroke pneumatic cylinder will get you pretty close, I believe.

I can't wait to see someone try this - it would certainly be exciting and any team that takes the chance on that kind of system would get kudos from me!

Even a spring/winch system will put some pretty awesome loads on your chassis.

Re: block thrown ball
 

I'm thinking a pendulum with a 20 lb sledge on the end...Winch it up and then power it down with gravity assisting. Maybe put a football kickers cleat on the end.

RAZ

Re: block thrown ball
 

This assumes, however, that you can get the volume of air to fill the cylinder quickly enough. A 2" cylinder takes a decent amount of time to fill up, given that all the air has to flow through tubing at 60psi. Just because you can achieve 220 lbs of force from a cylinder doesn't mean that you'll be able to deliver enough energy to lift the ball in the air.

Re: block thrown ball
 

why not bump them so they have to get out of the way

Re: block thrown ball
 

One problem...aside from robot damage, if the trackball does make it over, you just gave them 8 points because it hit you.

Doesn't work if they aren't impeding you. The ref probably won't call it if there is a passing lane or any other means of going around.

Re: block thrown ball
 

Read <G40> ... they don't always have to get out of the way ... only if they are IMPEDING traffic. They don't have to move if there is a way around them (clear passing lane around them), or if they are HURDLING.

Read <G42> and <G43> also ... they discuss that "aggressive" bumping a HURDLER will be penalized ...

Re: block thrown ball
 

Someone's probably said this but (ahem) "You cannot have your arm higher than 6 ft. in the opponent's homestretch".

Re: block thrown ball
 

Go read Update #1, and I mean now! <G36> has been removed.

Re: block thrown ball
 

Okay thanks Erich

Re: block thrown ball
 

Re: block thrown ball
 

What keeps a robot, with an arm, from turning around, after it crosses the opponents finish line, and knocking a hurdled shot back at the hurdling robot :ahh:

Re: block thrown ball
 

As long as you can hit the ball before it crosses the plane of the line, you are ok. Otherwise, it still counts as a hurdle if it touches your robot.

Re: block thrown ball
 

You can be above 6 feet now.

Re: block thrown ball
 

I was thinking that if the ball crosses the plane of the line, then it would count as a hurdle. So if one can hit the ball away before it crosses the line, it would prevent the hurdle.

But if they hit it after the ball crossed, it counts as a hurdle per the definition of hurdle:
Emphasis added.

Re: block thrown ball
 

Do you think the refs will consider the ball the way they consider the bots? What I mean is robot has to be fully over the line before it counts for points. Since the finish line appears to be equal/past the far side of the rack the ball would not be across the line until it falls off the rack so you could knock it back.
What do you think?

Re: block thrown ball
 

Since that is the definition of both hurdle and crossing, I think that is correct.

Re: block thrown ball
 

Yes, Section 7.2 Definitions:

CROSSING: The act of a TRCKBALL or ROBOT passing through the plane defined by a line (i.e. LANE MARKER or FINISH LINE) when it is projected vertically upwards. A TRACKBALL or ROBOT shall have CROSSED a line when all parts of the object, while traveling in a counterclockwise
direction, have completely passed through the plane.

I was directed to this def. earlier when I asked whether or not the trackball must also move in a counter-clockwise direction, otherwise, I missed it.