Grappling hook?

[bobmonkey836]

Originally Posted by Sean Raia

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.

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.

[Al Skierkiewicz]

Originally Posted by bobmonkey836

after all, mountain climbers+ gear tend to be well over 120 lbs, and those ropes will easily hold the weight.

Look up spectra cable and be shocked and awed. We have used it for many years including last year.

[viperred396]

Originally Posted by bobmonkey836

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.

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

[elmer_fud]

Originally Posted by viperred396

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/outdoorge.../EDL0009M.html (9kn is about 2000 lbf)