LIFT VS. LAUNCH

[RedHeadRobotics]

Our team will be building a catapult. We've built up a mock up with wood. It gets 7.5 feet consistently. It should get a bit more with the metal we hope. We also considered a lift, but we wanted to keep our center of gravity low.

[Torboticsmember]

Our team is going with a lifter this year. We basically ruled out shooting the ball because we thought it would be very complicated to design and then very hard to control where the ball goes, and finally we wouldn't be able to put the ball on the overpass at endgame effectively

[pafwl]

Originally Posted by Torboticsmember

Our team is going with a lifter this year. We basically ruled out shooting the ball because we thought it would be very complicated to design and then very hard to control where the ball goes, and finally we wouldn't be able to put the ball on the overpass at endgame effectively

I feel you with the whole endgame thing. That was discussed at length by my team however we concluded that the point differential 8 for a hurdle 12 for a place. Was just to small to change the whole design.

[dtengineering]

Launching is cooler than lifting, and you can bet you are going to see some neat launch designs... as well as some noble attempts that just don't quite cut it. Mind you, you'll see that with lifters, hybrid code, and everything else, too.

We decided to go with an arm to do the lifting, in part because if you have a partner (or two) each capable of quickly placing the ball on the overpass and then quickly lifting the ball from the overpass then you never have to give up posession of the ball.

Consider:

Robot A is positioned on the far side of the finish line, ready to lift the ball from the overpass.

Robot B approaches the near side of the overpass, places the ball on the overpass.

Robot C is doing a lap with a ball in possession.

Robot A grabs the ball from the overpass (hurdle complete now) and proceeds to do a lap.

Robot B crosses the finish line (completing a lap), and turns around - ready to receive the ball after C places it on the overpass.

Repeat as needed.

It will take three co-ordinated lifters and some excellent driving, but it would be fun to see three good shooters go against three good lifters. I'll bet that ball possession would come out on top.... unless the shooters had some way of catching the ball after it went over the overpass and were able to do a similar technique to the lifters.

Jason

[GaryVoshol]

Originally Posted by dtengineering

Robot A is positioned on the far side of the finish line, ready to lift the ball from the overpass.

Robot B approaches the near side of the overpass, places the ball on the overpass.

Robot C is doing a lap with a ball in possession.

Robot A grabs the ball from the overpass (hurdle complete now) and proceeds to do a lap.

Robot B crosses the finish line (completing a lap), and turns around - ready to receive the ball after C places it on the overpass.

Repeat as needed.

All without ever breaking the plane of the finish line going backward (clockwise)?

[pafwl]

[quote=dtengineering;682224]Launching is cooler than lifting, and you can bet you are going to see some neat launch designs... as well as some noble attempts that just don't quite cut it. Mind you, you'll see that with lifters, hybrid code, and everything else, too.

We decided to go with an arm to do the lifting, in part because if you have a partner (or two) each capable of quickly placing the ball on the overpass and then quickly lifting the ball from the overpass then you never have to give up posession of the ball.

Consider:

Robot A is positioned on the far side of the finish line, ready to lift the ball from the overpass.

Robot B approaches the near side of the overpass, places the ball on the overpass.

Robot C is doing a lap with a ball in possession.

Robot A grabs the ball from the overpass (hurdle complete now) and proceeds to do a lap.

Robot B crosses the finish line (completing a lap), and turns around - ready to receive the ball after C places it on the overpass.

Repeat as needed.

It will take three co-ordinated lifters and some excellent driving, but it would be fun to see three good shooters go against three good lifters. I'll bet that ball possession would come out on top.... unless the shooters had some way of catching the ball after it went over the overpass and were able to do a similar technique to the lifters.

Jason[/QUOTE

This was discussed at length with our team. I see your point but I think you are assuming to much. This only works if you have three good lifters. My team has always assumed that your alliance partners can achieve nothing to very little and then design around those assumptions.

[Laaba 80]

Originally Posted by dtengineering

Launching is cooler than lifting, and you can bet you are going to see some neat launch designs... as well as some noble attempts that just don't quite cut it. Mind you, you'll see that with lifters, hybrid code, and everything else, too.

We decided to go with an arm to do the lifting, in part because if you have a partner (or two) each capable of quickly placing the ball on the overpass and then quickly lifting the ball from the overpass then you never have to give up posession of the ball.

Consider:

Robot A is positioned on the far side of the finish line, ready to lift the ball from the overpass.

Robot B approaches the near side of the overpass, places the ball on the overpass.

Robot C is doing a lap with a ball in possession.

Robot A grabs the ball from the overpass (hurdle complete now) and proceeds to do a lap.

Robot B crosses the finish line (completing a lap), and turns around - ready to receive the ball after C places it on the overpass.

Repeat as needed.

It will take three co-ordinated lifters and some excellent driving, but it would be fun to see three good shooters go against three good lifters. I'll bet that ball possession would come out on top.... unless the shooters had some way of catching the ball after it went over the overpass and were able to do a similar technique to the lifters.

Jason

Robot A would not be able to pick the ball off the overpass without crossing the finish line clockwise for a 10 point penalty. The finish line is on the far side of the overpass, so unless the team can pick the ball up while only contacting about 5 inches or so of the ball, I dont see how it can be possible. Not a bad idea though.
Joey

[EricH]

Originally Posted by Laaba 80

Robot A would not be able to pick the ball off the overpass without crossing the finish line clockwise for a 10 point penalty. The finish line is on the far side of the overpass, so unless the team can pick the ball up while only contacting about 5 inches or so of the ball, I dont see how it can be possible. Not a bad idea though.
Joey

There is a way to do it such that no penalty is incurred. You have to have the right type of gripper, though.

[JohnC]

Originally Posted by dtengineering

Robot A grabs the ball from the overpass (hurdle complete now) and proceeds to do a lap.

Isn't there a rule about the ball touching the ground before it can touch another robot?

[d.courtney]

Originally Posted by JohnC

Isn't there a rule about the ball touching the ground before it can touch another robot?

Or another robot:

HURDLE: When a TRACKBALL CROSSES a FINISH LINE while passing above the OVERPASS
and then contacts either the floor or another ROBOT before re-contacting the originating ROBOT.

[Bob Steele]

Our design allows for us to "catch" the ball as it is hurdled across.
We would not try to catch a ball that is launched... but we can catch a ball that is rolled or moved across the overpass by our alliance partner.

During design you must think about this from the very beginning of the design and not try to add it as an afterthought.

3 robots in the scenario above is exactly what we are designing for.
This doesn't mean we can't hurdle and acquire the ball by ourselves.
But we are not only hoping to see it in Atlanta... we are designing for it.
We may not get to do it until then but we will be ready....

This could be fun...

[MrForbes]

Originally Posted by dtengineering

.... unless the shooters had some way of catching the ball after it went over the overpass

We're going to try this, but the problem will be that this can be defended against pretty easily, just have a robot running back and forth across the place where the ball is going to land.

[robot2226]

our team is using a lifter/launcher on ours. and its turning out very promising so far almost done too

[fireball3004]

Our team is making a lifter, we were thinking about launching the ball, but after some discussion with other schools we decided it might be considered dangerous. thoughts?

[MrForbes]

It can be very dangerous to make a mechanism that is capable of launching a ball that high, so you would need to go to a lot of extra trouble to make sure your design is safe. As I see it, the danger is not with actually launching the ball...the danger is that someone could have their bodily parts in the way of the mechanism when the ball is NOT in it, and it could give them a severe blow.

We figured out a way to use an air powered catapult that moves slowly if there is no ball on it, but with a ball in place, it is able to launch the ball quickly.

This is not an easy thing to design....so if you go this route, you really need to think about it carefully. We are using restrictor valves to keep the cylinders from filling quickly, and using an arm on top of the ball to hold it down, and the ball holds the catapult arm down. The system can only build up pressure when the ball is in place, and launching the ball uses up all this pressure.