Is it possible to have a hook shoot up at an angle with strong rope attached and latch on to the tower (assuming its in the height limits). then is it possible to reel the rope in?
This is just an idea our team has had and im wondering if it can be accomplished.
The only problem I would see is with the entanglement of robots or being hazardous to people. Rules <R03> to <R06> seem to say that it is essentially too dangerous to do so, and understandably so. I can only imagine a grappling hook shooting the wrong way and ramming into players or refs or destroying the field… not so great. Good idea though!
Yeah that was one of our concerns, and i doubt we will be using the grappling hook idea. But would it be possible to shoot the grappling hook out or reel the rope in and lift a 120 pound robot in the first place?
I want to know weather or not we should consider it as a plausible idea.
With the right material, I would say that that wouldn’t be a problem at all. There are many ways to lessen the strain, and I think it would be quite easily possible to engineer a way, be it pulleys or a fancy combination of motors to use a grappling hook to hang from the bar, and even great in the respect of not needing power while removing the robot. Again, I see the main concern as safety, and I think that will be the deciding factor.
We thought of this exact thing as well last night. Though we may have an idea on how to control it.
I don’t think this is possible as I think it’s likely that you would exceed your vertical allowance. The bars are 84’’ high your maximum is 90’’ so there’s only 6 inches of leeway for your shot to fly over the bar and grapple. Also if you happen to miss you would almost surely exceed your horizontal allowance. They teased us with the grapple bot in the kickoff video 
.
I saw several bots hang in 04 using hooks but the all had some type of arm extend up with hook on end to catch the bar and the hook and cable were velcroed so they would release from the arm and winch up the bots. Only purpose of the arm was to place the hook.
make sure the cable atached to your grapple is shorter than what the max is.
There are ways of using cables without “shooting” them up there. A shot is also inaccurate, dangerous, and possibly could go over the height limit… Try and think of more controlled ways to have a hook go up… you’re on the right track with cables…
I think our team is actually going with a scissor lift mechanism with hooks on the top. we want to be able to go under the tunnel. I just thought the grappling hook was a neat idea for discussion, and im from what i read its possible and legal if it doesn’t go outside the dimensions.
we decided to opt out of the hook because the max hight during FInal Configuration is 90 in and the towers height is 84 in so the hook only has 6in to make it over and we didn’t want to risk going to high.
<G40> also might say its a no go because of the entanglement issue
edit: sry i re-said things others did i didn’t notice them until i reread the thread
Of course you can lift a robot using a hook and cable as described. We have done it. There will some risk involved this year…
<G31> BALL RETURN and RETURN BARS Protection - ROBOTS may not contact the BALL RETURN or the RETURN BARS (black tape). Violation: PENALTY for inadvertent contact; plus a RED CARD for obviously intentional contact or damaging contact.
it’s very plausible. if you could get the accuracy, you should have the strength pretty easily after that. after all, mountain climbers+ gear tend to be well over 120 lbs, and those ropes will easily hold the weight.
Case in point, Team 811:
The black pole on the right telescoped out ~15 feet to put the grappling hook over the 10’ chin-up bar, and then a window motor (legal then) pulled Red Streak II into the air v-e-r-y s-l-o-w-l-y .
Look up spectra cable and be shocked and awed. We have used it for many years including last year.
I remember reading somewhere that after hanging a large weight from one of those ropes you shouldn’t use them again because they might break. even if it hold during testing and the practice matches but then it might break in the qualifiers causing you to lost
I think climbing rope will be overkill. A climbing rope will require something over 1000 pounds to break. Some parachute cord (1/8 in rope) has a breaking strength of 300 lbs but you would likely break this using it with a 150 lb robot. I think something in the area of 3/8 inch rope would work well
With climbing rope you are not supposed to use it again after a hard fall ( several feet) because it is weakened. Putting 150 lbs on it repeatedly will not hurt the rope.
references
parachute cord http://www.rei.com/product/784296
climbing rope http://www.backcountry.com/outdoorgear/Edelweiss-Ally-Single-Climbing-Rope-103mm/EDL0009M.html (9kn is about 2000 lbf)
Team 975 used a telescoping tube made from nested PCV pipes. There were flat-wound clock springs to extend the arm segments and a small steel cable/winch to control extension and lift, and a hook on the end that was loosely attached. It worked fairly well. In one match at the VCU regional, all four robots were hanging from the bar. That year’s robot was unofficially named “hooker”.
It’s the lowest one in the foreground. (Check out the officials in the background - everyone went wild.)
http://www.chiefdelphi.com/forums/attachment.php?attachmentid=8300&stc=1&d=1263487046
Yea I don’t think that the Grappling Hook would be such a good idea for this game, but in general it is a good thought. Maybe it can be used in a game in the next few years but I wouldn’t for this because it would be dangerous. Plus, what if your hook missed the pole and it latched onto the ball return rack, It could destroy the return rack, which would not be good for your team or the actual competition.