Springs?? (10 lbs. at 22 ft/s)

[Gdeaver]

The energy to launch a ball is lot. I'm concerned with having that much energy stored in a mechanism on a robot. If the release mechanism fails and the energy can not be released by remote means how is a team going to defuse the bomb. What happens if the device is cocked with out a ball and it is accidentally released. What if a small object like a bolt was on it when it was accidentally released or a hand was in the way. This seams like a risky path for teams to take. Think long and hard before going down it. Because something can be done does not mean it should be done.

[MrForbes]

The energy to launch a ball is similar to the energy the ball has when it's sitting on the overpass. Hmmmm.....

A nice thing about air, is that it can be released with a valve that is accessible away from the launch mechanism.

[jimwick]

An idea from team 885

What about using an "air spring?" (See McMaster Carr catalog.) I'm not talking about those gas springs that hold up the trunk of your car, but an industrial air spring.
The spring could be charged up for every shot by the compressor, and then left discharged (relaxed) to reset the device. You would need a sturdy release mechanism acting upon some kind of sturdy boinker.

jim wick
mentor for team 885

[MrForbes]

You can use the Bimba cylinders that are listed in the pneumatics manual, but you cannot use other pneumatic devices, so it would probably be illegal to use what you suggest.

But the Bimba cylinders can be used the same way, if you think about it....start out with the cylinder partly extended, fill it up with compresssed air, release a catch, and the ball goes flying.

[Brandon Holley]

Originally Posted by pfreivald

I'd love to see it, and I hope it works out well -- nowhere in my remarks was I being in any way sarcastic. I wasn't even being _pessimistic_.

It is not unreasonable to point out that certain approaches are harder than others, and also that the act of physically launching the ball carries a great deal more safety issues tied up in it than lifting the ball in some manner.

I certainly _do_ hope to see safely-launched balls. I certainly _do_ hope that all teams rise to the challenge of this game in the best way that they know how. I certainly _do not_ want to see teams that cannot hurdle at all because they haven't fully considered all of the ramifications of their approach, and now have a robot that will not be allowed to play based on safety concerns.

How awful would it be to show up with a fully-functional, killer-app bot and then not be allowed to use it? The fact that the judging of the safety is both discretionary and subjective just means that even more caution needs to be taken.

It _is_ quite amazing what thirty-thousand minds bent to a single task can accomplish. I'm sure some teams will pull off safely-launched balls, and be both effective and amazing. I'm *not* so sure that they'll do it with a spring capable of throwing 10 lbs at 22 ft/sec, which is the topic of this thread.

Patrick

Patrick,
I apologize if you think I was be condescending earlier. And you are correct that it is not an easy task to launch a ball safely.

However, I am 100% certain it is going to happen, as I'm sure you are. I just feel you may want to be more careful in what you say (as what you said sounded pretty pessimistic, even if you said it in an optimistic way).

Brando

[charlie1218]

Im not saying this will be safe but. use a Constant force spring, they dont even look like springs haha, they use them in car seatbelts. Our sponsor Vulcan spring corp. Is the sole manufacturer.