This is the Akimbo

I am still tweaking and @Steve Connally is helping me out with some test ropes. For kicks, I did just try switching to 3T 3B on the Akimbo on my Scion line, it took care of the boat anchor drag, but now it takes it 8-12" to catch when I load it unless I manually flip the top up, and if I bounce I can get it to slip slowly. I will post results from the other lines when I test.
 
FreeFallin said:
I am still tweaking and @Steve Connally is helping me out with some test ropes. For kicks, I did just try switching to 3T 3B on the Akimbo on my Scion line, it took care of the boat anchor drag, but now it takes it 8-12" to catch when I load it unless I manually flip the top up, and if I bounce I can get it to slip slowly. I will post results from the other lines when I test.
Click to expand...

Now with that same top move the bottom one hole in each direction.
 
Oddly enough, on the KM Max, if it has just a little creep (3 or 4 inches) and I bounce on it, it grabs tight and stops. If I set it on 11.7mm to creep a little, bouncing on it makes it slide further. The cam/rope friction seems to be very different for each rope, even to the point that an adjustment in one direction on either cam has opposite effects on the creep. I wasted a lot of time adjusting it tighter on the smaller, slicker KM Max rope, and ended up adjusting both cams looser to make it work. That's why it ended up being the same settings as for the 11.7mm (larger) rope. With the KM Max, it appears that opening it up actually increases the leverage effect on the rope, and that gives more grab than tightening the cam adjustments. Strange, and not what I expected, but this is a very subtle device when it comes to the rope interaction. I've found that starting at 4T/4B for everything gets me some working settings the fastest. Trying to predict which cam needs to go which direction seems like an excercise in futility, I just pick a cam and move it one direction one way, then move it one direction the other way, and see what effect it has. Then I switch to the other cam and do the same thing. That seems to get me to some good settings fairly quickly. It's a funny animal, but when you hit the sweet spot... sheesh... the thing is just this very simple, compact thing hanging there that replaces all the clutter and parts of the RW setup. And, just a few seconds to take it on and off. I mean, this is what an SRT device should be. I can live with the extra time it takes to figure out the right settings. I can sit in my livingroom and do that. I can tell when I've got it right, now, because after playing with it on a few ropes you can just feel when you've hit the right settings. At most, I move one cam setting or the other one hole under full weight.

I wish I could say how this compares to the RR, but I don't have one. From what I've seen on here, it has some finicky properties with rope interaction, too. That shouldn't be a surprise to anyone. Magical or wishful thinking doesn't alter physics, it's playing with these great innovations that sheds some light on how the next such device should work. It's fun to watch the progress.
 
I remember reading about that, too. The dyes and coating apparently have a quite noticeable effect on friction. My vision isn't good enough to see the molecular differences, but I'm willing to assume that this is true. I just don't happen to have a lot of different colored versions of the same rope, but I've seen quite a few people mention it. Especially about the Calamine version.
 
Worthaug said:
Get it in the rotation and get that MaxiJacket rubbed off it, Frank. Prism is the the shizzle me nizzle.


Reed Wortley
CA# SO-6953A
CTSP# 01739
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I will do that Reed, thanks. I bought it as a second 11.7 for those times when I want a second tie in point so it sees more rope bag than day light.
 
JeffGu said:
it appears that opening it up actually increases the leverage effect on the rope, and that gives more grab than tightening the cam adjustments.
Click to expand...

This kind of made a light go on for me, I thought I had the forces clear in my head, but I don't.

If you look at the RW, the forces seem pretty clear cut, you have the distance between the cams, and the angle of the wrench at play. This creates a 2 lever system that impacts friction on the rope, the math for that is complex but most people can look at a wrench and figure out they need to either adjust the cams or the angle of the wrench.

I was looking at the Akimbo like it was just 2 inverted RW's making it a system with 4 levers (the cams) at play and still fairly easy to understand - but it's not. Those 2 hinge points on the back add 2 more levers, making it a 6 lever system where each lever introduces a variable that effects the force on all of the other 5. Frankly at this point the math and force visualization both exist somewhere in the ether beyond what my brain and education can reach.

That's even enough variables at play to make Mumford scratch his head for a few minutes (@yoyoman ;)).

With all that said - increasing the distance between 2 of the top or bottom cams would logically reduce friction, however, what it actually does is increase movement in the hinges, and like pulling down on a RW, passes power to the arms for wrenching, which can increase friction. In the overall system.

This is why you have to test the settings with the tail slacked, like it would be while descending, AND while tensioned, like it would be during ascent.

Did I mention this thing is genious? Well it is.

:bananahappy:
 
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So maybe my problem is not having the top loose enough. I find with a loose top it seems to want to slide down the rope quite a bit when it doesn't have any weight on it. So would you adjust the bottom to grab and the top to be pretty opened up? My device doesn't open up much when its loaded. I may have just figured out that I have nothing figured out.
 
@FreeFallin i love that you have put so much thought into your interaction with the Akimbo! im pretty sure the one you have is around two revisions older than the current prototypes. that particular on i could never get to work on scion and that was one of the things that prompted me to alter it. from about the time the spring cam was introduced all of the alterations have been pretty subtle. an extra 1/8" length here, a slight shift of the shackle there. @JeffGu sounds like hes pretty much got the best method for dialing in the settings. go by feel and try both directions because there can be some very counter intuitive results. because the adjusters are eccentric and rotate around a fixed point your not only changing the distance between the cam and bollard, your also changing the sharpness of the "s" bend of the rope through the top arm and the effective leverage of the bottom arm. im trying to work out a way to make the adjustments a little more intuitive as well as making them a little less sensitive. i like that there are so many possible settings, but id like to see a lot more overlap between settings. that would help make adjustments less finicky.
 
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