Two ropes? pffffft that’s nothing compared to some teams that brought 24 ropes
Some teams bring a lot of ropes because they break a lot of ropes.
Other teams have ropes that don’t break. They don’t need as many.
Yep. We brought two for safety, but never had any ropes break. It was nice to have a spare if a knot came loose. Our team cadet worked diligently to make sure they were corrected while we played.
Only 2? Wow… Our team brought 8 to our first regional, 26 to our second, and are making 32 more now for St. Louis… I guess that’s what happens when a rope snaps in the playoffs.
We have one rope. It’s rated for an absurd amount of weight.
Most ropes seem to be failing due to unnotice abrasion, or failure of enough strands to allow total catastrophic failure while under load. We’ve avoided that by going with such an absurdly overbuilt rope that we’re not concerned with fraying ends or broken strands.
Completely agree. You have a rope break 3 times at an event and you check it after every match and make 7 more to bring to the next event. I think we’re bringing 10 or so to Houston.
Our 1" Kevlar webbing rope held up extremely well once we started using it at Smoky Mountians. We just have to find a way to make it play nicer during initial acquisition. It is a bit thicker than our original ropes and doesn’t like to comply with our robot’s wishes sometimes.
If your rope is like the OP’s (Velcro on webbing) I have a suggestion for you. 6328 uses a Velcro on webbing rope, but found that using the sandwich method, (like the rope in the photo) left the two tiny “faces” of the webbing exposed (while covering the large faces quite nicely). Once in a blue moon during practice, we would approach the rope and happen to hit one of these faces, meaning we didn’t grab the rope as easily.
Rather than building a sandwich, we actually bend Velcro around those faces like this… —]
where the represents the Velcro and the — is the webbing
This covers every face, and while it does leave a small gap between Velcro pieces on the large flat surfaces, those are covered to an overkill level anyways.
We do use 3/4" webbing however, which allows us to grow a bit, which happens when you add the Velcro like this.
IMO, I don’t get why so many teams are using absurdly small ropes. The rope is one of the least regulated items in the game, there’s no weight limit, tons of material options, and can be up to 1" wide. If you have to bring 24+ ropes to an event (unless there is some SERIOUS cheesecaking going on) I feel like you might be doing something wrong.
My team used a 1in ratchet strap with Velcro sewed on (only brought 2 ropes), it did break once when the driver attempted to keep climbing even after the rope had become jammed on the spool. Driver started watching for this and we had no issues with the rope beyond that one.
The straps we are using are 1" thick with a 1" thick velcro piece sewn on and are rated for Cargo loads upwards of 500lbs. I do not expect them to break but we have two just in case.
Also, we haved experienced any issues with the spool touching the sides and not catching on the velcro yet.
Ours look similar, but with that particular design is violated this rule:
I. be flexible such that it’s not capable of being pushed to activate the TOUCHPAD.
Flexible means that if the ROPE is held at any point, it should not extend
more than 12 in. (~30 cm) above the point where it is held. ROPES are
meant to be pulled, not pushed.
To combat this, we did many variations of smaller pieces of velcro stitched in with and inch or so gap between them.
Especially with the —] style this became an issue for us as well. Not to an extent that we would violate the rule, but the stiffness made for less than optimal catching of the rope.
We determined that “massaging” the rope to loosen up the stitching actually helped a bit. It also fluffs up the loops. As we got better at sewing, the ropes got stiffer, so we try to sew them loosely now to keep them floppy.
We brought 6 ropes with us, not for fear of breaking them, but because new Velcro seems to perform better than used Velcro.
Climbs are valuable, ropes are cheap.
I would caution you to make more spares unless you have an intelligent way to make the robot stop climbing. At Mt. Olive we managed to snap 600lb rated webbing three times.
There are few times I openly admit Richard is right, but yeah, an overbuilt rope was the right call here. Ours frays a little, but not nearly enough to risk a snap.
We have used BlueWater ropes, 1’ webbing with great results. So far we have not had a rope cut by the davits and are getting over 15 climbs out of the roper before it shows any signs of abrasion. Found it on Amazon, . Rather than velcro we used a card file to rough up then ends.
I can vouch for this stuff, having spent a few seasons of my mis-spent youth as a rock climber. On several occasions I found myself suspended from Blue Water tubular webbing, in situations that would have been perilous without it!
This webbing’s tensile rating is ~4000 lbf, which is about the same as the 3/8" Sta-Set sailing line than my team uses as a STEAMWorks climbing rope. Both are excellent choices, IMO.
My team uses 550 paracord with a double layered tube webbing as a sheath. Teams shouldn’t be worried about ropes snapping because of weight unless they are using twine. The davit itself is very sharp at the top and at the botom, that is what makes ropes and webbing snap. Proper protection (like tube webbing) and inspection (for fraying) of the rope after every match is crucial to consistent climbs every match.
The vast majority of breaks I have witnessed are actually from the robot not stopping and trying to drive through the steel davit as most of the breaks are due to obvious stretching, or compromised ropes to begin with, and not at the top angle or the bottom edge of the davit. Figure out a way to stop driving the climbing motor when you get to the touchpad (HINT: the PDP has electrical current numbers available for every port), and you are much less likely to break your rope. Not swinging during the climb will help as well. Your rope will lose the battle with the davit if you don’t figure out how to stop your climber.
One of the more interesting breaks that I examined this past week was paracord. A core line that was completely interior in the winding before the break happened let go and unraveled the rest of the wraps around it. The line itself didn’t look new, so I have no clue what the history of it was, but a few climbs did it in. It was kind of cool how the bot pretty gently dropped to the ground as the windings unwound.
We always kept 4 ropes (we use 5/8" nylon webbing) on hand at our last district event so that we could go to our next match without having to wait for me to reset the rope to its original configuration. We did lose two ropes: one because I wrote on it in Sharpie, not knowing that that was against the rules, and the other after it got punctured in multiple places by the bolts on our climber.