This is the Akimbo

oceans said:
Oh, bummer, because for a second there I was thinking I wasn't the only one. :(
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Oh I've dreamed of the Akimbo, it gives me super powers... I don't think I'll be let down either.
Jamie, can you just make an animated GIF of the Akimbo opening and closing, on repeat.. for me to watch.:popcorn:
 
JeffGu said:
Hey, no gear porn... this a family channel... kids could be watching, and the price of Xmas would skyrocket.
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Mmmm...... Gear Porn!!
drool.gif


I must confess though that I'm inexplicably happy to not be the Only one getting withdrawal symptoms from something I've never seen/used/had!
 
So. First destructive test results are in. Just one unit tested and broken so far but very informative. First it was pulled to slipping, then it was rigged with a biner in the bottom and a biner around the top eccentric pin and pulled to breaking. It slipped around 500-700lbs and it broke around 3500lbs. the way it broke was the machine screw head popped off of the eccentric pin on the slot side, allowing the pin to bend out of the slot and ultimately break. easy fix for that is to machine the pins with an integrated head rather than a screw. im also thinking another test is in order with a different setup. im thinking another setup might be to set the Akimbo on a rope and spike the rope beneath the upper arms. that would come closest to realistically loading the unit. thoughts?
 

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Info is always a good thing. Can I assume the head that popped was off of an 5/16 (8mm) shoulder bolt? That is a low number for that to break. Any chance that the biner was can opening against it?
 
JMerritt said:
So. First destructive test results are in. Just one unit tested and broken so far but very informative. First it was pulled to slipping, then it was rigged with a biner in the bottom and a biner around the top eccentric pin and pulled to breaking. It slipped around 500-700lbs and it broke around 3500lbs. the way it broke was the machine screw head popped off of the eccentric pin on the slot side, allowing the pin to bend out of the slot and ultimately break. easy fix for that is to machine the pins with an integrated head rather than a screw. im also thinking another test is in order with a different setup. im thinking another setup might be to set the Akimbo on a rope and spike the rope beneath the upper arms. that would come closest to realistically loading the unit. thoughts?
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:(oh man...it's even pretty when it is broken. ...so, what are the broken ones going for...;)
 
JMerritt said:
So. First destructive test results are in. Just one unit tested and broken so far but very informative. First it was pulled to slipping, then it was rigged with a biner in the bottom and a biner around the top eccentric pin and pulled to breaking. It slipped around 500-700lbs and it broke around 3500lbs. the way it broke was the machine screw head popped off of the eccentric pin on the slot side, allowing the pin to bend out of the slot and ultimately break. easy fix for that is to machine the pins with an integrated head rather than a screw. im also thinking another test is in order with a different setup. im thinking another setup might be to set the Akimbo on a rope and spike the rope beneath the upper arms. that would come closest to realistically loading the unit. thoughts?
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Do you feel it inside, deep in your heart, when it broke? I can't even imagine. Good on you.
 
JMerritt said:
So....thoughts?
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I think there are a few important tests. You need to know the strength of the attachment point. In order to do that, you need to spike below the unit and pull to failure. Something will break...maybe the rope.

Next, you need to know the strength of all the connections of the major components. This might require a straight pull between the attachment point and the top, outer bollard.

Lastly, you need to know how it performs on the rope. As you've found (and similar to most mechanicals), it will slip, initially. Ideally, it would continue to slip before something failed, but if you could get all the components to behave well on a rope (while climbing) and have it hold until 5,500 lbs., that might be great.

I've said this before, but I'll repeat myself since it seems to apply here, that I think a mechanical belay should slip just above 200% of the climber's load, unless it's intended for a two person load. This is a bit of a built in energy absorption characteristic.
 
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JMerritt said:
some drop testing has been done as well and it behaves just as you would hope. it slips some distance and slows to a stop. distance depending on rope and setting.
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That's great. Might be a lengthy measure, but it sounds like it may be a good idea to write diameter ranges into the device so the user has a visual while adjusting during a climb. That would take a bunch of testing with various ropes, but I feel it's a realistic effort, and worth while.
 
Unless I am misunderstanding what you mean, that might be a tall order, Eric. Having used the Akimbo I can tell you that the eccentric cam adjustment is not totally different from fine tuning a hitch. By that I mean that there is a range that will work but because of rope and situation variables it takes tuning to get perfect.

It would be almost like asking what rope and hitch would be best.
 
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There will be some sort of notation on the adjustments. I shy away from printing numbers there as DSmc says, it is impossible to predict settings for all of the ropes out there. Some system of symbols or pictograph communicating increased or decreased friction/holding power seems appropriate. My ultimate plan is to partner with a rope company and come up with some tested combinations that can be relied on for consistent and repeatable results. Not unlike treemagineers ce systems. It wouldn't mean that you couldn't use any rope you want, but it woul give the option of a certifiable and tested system.
 
The subtlety understanding function (user)is quite different from preparations for certification (manufacturer), there is a massive hole waiting to be filled be an EN certified multiscender, I wonder if your device is it? Testing to existing standards or writing your own is achievable though I wonder how serious you take the European market? The Berufsgenossenschaft, Germam Treecare Insurer, has put a pro-active ban on all non-certified equipment, I'm sure they are eager to hear of a solution as SRWP climbing gets more and more use.
There are interested people waiting to help, get in touch.
 
JMerritt said:
There will be some sort of notation on the adjustments. I shy away from printing numbers there as DSmc says, it is impossible to predict settings for all of the ropes out there. Some system of symbols or pictograph communicating increased or decreased friction/holding power seems appropriate. My ultimate plan is to partner with a rope company and come up with some tested combinations that can be relied on for consistent and repeatable results. Not unlike treemagineers ce systems. It wouldn't mean that you couldn't use any rope you want, but it woul give the option of a certifiable and tested system.
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That's what I was getting at. I just think the climber needs a bit of clarity in one way or another. I don't know what the Akimbo is like to hold and adjust. I'm speculating.
 
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