Gumball Quickdraws
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AndrewArroz wrote: +1 Don't fix what isn't broken |
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GregMiller wrote: Yeah I think it would make back clipping much more dangerous. Besides that, I don't think it has any particular problems, I just don't think it solves any either. Curious to see what sort of backing it gets from the community... |
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Benjamin Anderson wrote: Call me jaded, but I think the real goal of all this is to get an A in their Design-Entrepreneur class. No doubt the project syllabus calls for the design to be commercially viable, and these students have made adequate progress down that road IMO to declare victory. |
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Well, then, I hope they decide to refund the >$5,000 they've raised on kickstarter rather than blowing it on beer money |
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People who backed it will only get charged once it gets to its goal of $10k. They have not gotten any money yet, just pledges. |
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Here's some real carabiner innovation: |
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Thanks for the continued feedback folks, and sorry for the hiatus. I'm not sure we're quite ready throw in the towel if we can create a viable product with some tweaks ;). We've gone back to the drawing board with the design, and want to leverage this forum as a source of quick and dirty feedback so we can iterate before we reproduce a lot of materials both digital and physical. Here's what we're working with currently to alleviate the back clipping issue: We're looking to find the correct angle for the overhang as a way to fix this issue. My personal opinion is the elbow above is unnecessary so long as there is still an overhang similar to the Mad Rock Angler. What do you think about what's pictured above vs. something more flush? Does the additional tendency for the rope to redirect with what's pictured above outweigh potential clothing snags, etc.? Again, this design is meant to create discussion around the concept; our engineer is contracted and we want to bring something rough to him to save a few dollars. Cheers, Steve |
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I think you really need to look at your basic design concept before you spend too much time. Think about the main design requirement. #1: Carabiner needs to hold load. You have shown no hand calcs to show that the nose design will provide appropriate load carrying characteristics. You need to do this first because if it doesn't meet it, you will need to redesign the gumball and the wire gate. No point in prototyping if it has no physical chance of being safe. The nose hook "looks" too shallow and the wire gate might be too bent for it to play sufficient structural role when the carabiner is loaded. Without the calculations, though, you don't know if your concept is even physically viable. What's the point of designing and building something that has the potential to not perform its primary purpose? This is the difference between "design" and "engineering." You need to make sure your basic function (the nose design safely holding a fall) works before you sink too much time into a concept that wouldn't have worked no matter how much you tweak it. Do your hand calcs, or find someone with expertise to do them. I applaud the effort to design something new, but I think you should have your priorities ironed out and step through the process (load hand calcs on the concept) before committing too many resources (buliding a prototype and testing) for something that may not work out. Note: testing and iterating can work it out if you have cheap/efficient manufacturing and testing. Forged part iteration is not practical. CNC machining/additive, while cheap and fast, will not get you the material properties you need to pass test. So, you are likely relegated to hand calcs & FEA before you do your prototypes. Anyway, I'm not a carabiner engineer (although I am an engineer on critical components), so take these comments as suggestions with a grain of salt. |
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Just in case you're not catching what polloloco ^^^ is saying above. There has been valid concern mentioned from him and a few others, that the nose/gate interface isn't large or strong enough to hold onto the gate and give the carabiner the carabiner the strength it needs. There is often enough vibration and flutter of a gate when taking a fall that if the lip on the nose isn't large enough to maintain contact with the wire gate than the strength of the carabiner is greatly reduced usually by about 2/3. i.e. most carabiners have a full strength rating of around 22-25kn, but the gate open rating is more like 7-9kn. It would take far less material to beef up the nose a bit than it would to increase the thickness of the stock to get that same strength rating. The tiny lip you currently have seems like it's not enough to give a reasonable margin of error if the carabiner flexes, or the gate flutters, even a little bit. |
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polloloco wrote: Good deal, this will be a priority in our next revision, and we'll get hand calcs from our Solidworks partner. We had gotten feedback on back clipping so that's what the image posted was geared towards. Given that we can engineer a solid hook, what are your thoughts for the structure of the top of the biner (i.e. elbow vs no elbow near the top of the frame)? Best, Steve |
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Anchor Labs wrote: Another possible factor that may reduce the strength is the shape of the bottom. In the new version you show in the pic above, the bottom of the biner is shaped a little like an oval, which means that, under load, there may be a significant lever-arm on the backbone of the biner. D-biners are stronger because they reduce this lever-arm. Yours has a D-shape at top, but not so much at bottom. |
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When your carabiner turns upside down in the draw (and they do) your overhang becomes a hook. I still think you're solving a problem that doesn't exist. You might try to gauge what sales are like of the Mad Rock Angler draw to see if there's a demand for this "solution." Given I can only see 1 user review on any of the sites selling the product I'd guess that they're hardly flying off the rack. |
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To answer your question about the angle of the lip at the top, I'd go with no elbow purely for aesthetics. Additionally, I wouldn't put a sphere on the top lip for two reasons 1. I think it looks goofy, the madrock upper lip is a more streamlined design that is visually appealing. 2. Isn't the point of the sphere for the rope to catch on it? Wouldn't having a sphere there make the rope hang up on the top of the biner more? I'm sure eventually the biner would rotate under the load of the rope and the rope would fall off, but why design it that way? One last thought: I may be wrong but as long as the lip overhangs the gumball I think it will mitigate the chance of unclipping. I'd be more concerned with the length of the top lip than the angle. I'd imagine that depending on how the biner hangs in the dogbone will determine how long the lip needs to be. I'd test that with rapid protoypes. |
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The real problem with this design, IMHO, is that its likelihood of catastrophic failure (unclipping during a fall) can't be replicated in a lab, and can only be evaluated in real use. There are an infinite number of scenarios where "standard" wiregate carabiners can fail, and none of them occur in the lab, or the carabiners would never get to market. Your design increases the likelihood of the 'biner unclipping, trading safety for convenience...no one would willingly put themselves at risk this way, even in the gym. It's like building a car with three wheels, and warning drivers not to take a turn too fast or it might tip over. Except with this design, you can't even warn climbers under what scenarios it might make unclipping more likely, and there's nothing a climber could do to mitigate the risk, short of adding a second 'biner with the gate opposed (there's a reason people still use locking carabiners). Another issue that hasn't been brought up yet is the likelihood of the knob catching on some irregularity on the rock from simple rope drag through the 'biner, which could lever the gate open and let the rope slip out. There's a reason 'biners have evolved to be as streamlined as possible, and why wire gates are not the only 'biner design. Every design has tradeoffs that must be balanced against the ultimate criterion, which is the safety of the climber. Your design increases risk of accidental unclipping without demonstrably improving safety in any other way. Even the idea of making this a "training device" is a weak proposition, since the "trainee" must transition to a real carabiner and "relearn" how to clip a different device. The real problem is that carabiners are a safety device first and a convenience second. If you emphasize convenience over safety, you're increasing the risk. This is one of the few markets where that's an unacceptable tradeoff in the real world. |
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Kyle Tarry wrote: |
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Just gonna leave this right here, for anyone actually thinking about buying an easy to clip/snag QuickDraw. https://www.mountainproject.com/forum/topic/106879587/accident-left-gear-on-break-on-through-eldo-on-94 |
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Anchor Labs wrote: |
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Anchor Labs wrote: |
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Cause the Spirit 2015s are so... so... hard to clip. Cut your losses and stop wasting your time on this |