So the long discussion is still going on in our shop about the use of Hook and Loop as an aid for climbing.
We are split in the shop,
Meow can you help me find evidence to support the use of hook and loop sewn into a 1" tie down strap and use it for our climber. I try to tell them, its up to the inspectors and if they don’t approve then they need to have evidence to support it, and articulate it. They need a little help.
Thanks for your help, this will help us more forward with designs.
Have a mice day.
consist entirely of flexible, non-metallic fibers sewn, twisted, tied, woven, or braided together except for the last 4 in. (~10 cm) of any cut end (E) which may be whipped (with material that is flexible and non-metallic) or fused only to prevent fraying.
Grab a short length of the hook and loop you’re considering using. Disassemble it. Once disassembled, can you confirm that it’s made only of flexible, non-metalic fibers? Can you confirm that it was assembled using sewing, twisting, tying, weaving, or braiding? Bonus question is there a difference in either parts or assembly between the hook side and the loop side that may have an impact on I04 part D?
I think the rub of the matter depends critically on how velcro is actually constructed - does anyone know whether or not loop-side velcro meets the requirements of “entirely of flexible, non-metallic fibers sewn, twisted, tied, woven, or braided together?” I don’t have any on hand, and looking at close-ups on google images is unenlightening.
If they were, I suspect that Velcro strap would come apart a lot easier than it does. Pending specific evidence, 3946 is working based on the assumption that those fibers are fused together, so Velcro is out as part of the ROPE. Your assumptions and evidence may vary.
You see, this is why I am entirely dissatisfied with the current ruling. At best, the rule allows team that manages to find a brand of velcro that is constructed a certain way (or convince their regional inspector that it is so) to have a wildly different functionality available to them than one that cannot.
At worst, the rule allows velcro to only those teams that can somehow manage to manufacture their own velcro.
I understand the GDC’s desire not to provide input on certain mechanisms, but there comes a point where in the interest of fairness they must do so.
Anyone go down to a local fabric store and ask what fabric is easily caught by the Velcro hooks?
“Our problem with Velcro is that its hooks easily grab onto articles of clothing that they were NOT intended for - especially, for example, knit fabrics used for nordic ski suits, and cycling kits. When the hooks brush against the synthetic fibers of polyester, they agitate and pull at them. Even very slight contact with Velcro causes yarn breakage or what we call fabric picking - a process that results in fiber ends that have pulled away from the fabric surface. Ouch!”
Please note that that data sheet (probably the best term for it in this context) only applies to the specific products listed on it. It does not apply for all hook and loop materials that a team can purchase. Results may vary with different brands or different models (If Velcro has other models) not listed in that document.
I will state again that if the pragmatic effect of this rule is that functionally-equivalent products from different brands have differing legality, and so teams who didn’t happen to purchase the right brand of velcro are in violation of the rule, then it is a bad rule and should be changed.
There are lots of products where it’s probably nearly impossible to ascertain the legality under the current ruling, as well.
You could say the same thing about pneumatic solenoids or pressure regulators or motors that are similar to legal motors but not on the list, or fans, or, or, or. That’s why we have rules that define what is and isn’t legal. The goal IMO is to provide a specification for what is legal and have teams figure out if the material they want to use is legal within the rules. Velcro happens to be this year’s tricky item, but i would suspect most (>75%) teams have local sources of velcro that are legal and local sources of velcro that aren’t.
I would expect to find legal velcro at fabric/sewing stores, and possibly at home stores, and illegal velcro certainly in both.
As with all items not explicitly mentioned in the rules, it is up to the team to prove to the Robot Inspectors that the item is legal. This is best done by showing a product sheet describing the product in terms that agree with the rules. So if you are using a hook and loop fastener product on your robot, perhaps you should bring a product sheet from that particular manufacturer with the same model number that appears on the invoice you have for its purchase. If that product sheet meets the description of a FIRST compliant rope, and doesn’t violate any of the legal descriptions ( a WOVEN stainless steel rope would not be legal, just because it’s woven), then you have a much better chance of making the LRI happy.
If, however, you have just any old hook and loop, and try to use Velcro’s description of a very particular product which is woven, then expect some careful and pointed questioning. At my events, you will need to show that you, in fact, are using the product described in the product sheet.
Personally, I’m at a bit of a loss as to why there is still any controversy. FIRST has a default rope for any and every team that elects not to bring their own. FIRST also allows teams to fabricate their own ropes (emphasis on the PLURALITY of ropes that teams are allowed to bring to competition and have inspected), as well as share. Getting a single rope of the many ropes teams are allowed to bring to pass inspections isn’t a requirement for teams to compete. There isn’t a requirement that the ropes be identical either. There is no requirement that a rope contains a component of hook and loop fastener either.
The rule is pretty clear on characteristics of materials that are allowed in a rope, as well as how teams can fabricate their rope. Any team that shows up to an event with a rope containing illegal materials, and I’m certain there will be multiple of teams there to help them fabricate a legal rope or loan them a spare.