Ropetek Hitch Hiker

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  • #201
Is the dogbone steel?looks to me to be the main 'link' to be researched.
What bending force would it take before failure, especially with the shape which incorporates an edge or two which might well be considered stress-risers.

Pigwot the dogbone is 4142 hardened steel 1/2" and the forces on it are mainly shear as the hitchcord is secured 1/2" from cheek plates. Don't worry as soon as we get it all nailed down we will conduct a full array of testing. I could be wrong but I cannot imagine any hitch being able to hold enough force to break that dogbone.....
 
New direction.....

It looks like the hitch needs to be tied, then thru the dogbone, and have stopper knots tied, somewhat making it where a person will have to fight to get the stopper knots untied in order to remove the hitch from the rope.

As is, the stopper knots on the hitch cord are pulling up on the dogbone, guided by the slot, forcing the dogbone against the rope, and rope against the body.

Is it possibly to somehow change the top slot angle (or something) and/or move more force to the bottom biner/ rope area/ body by threading the dogbone and tying scaffold knots on the lower biner on each side of the body? I know that threading the dogbone to the biner will have a lot different vector force on that top dogbone (much less force).

Where is the force being split on the latest configuration between the dogbone and biner, to your guestamation? 50/50, 60/40, 40/60?




Another thing that I wonder about, that seems likely not to be a problem, but at least something to consider/ rule out, is whether there is a high pinch point force on the rope from the dogbone and/ or biner. Seems like the force is spread out between the hitch, dogbone, and biner pretty well.

With a Gibbs ascender, where there is one pinch point, a shockload from a fall can part/ break the rope at a significantly lower force than the typically breaking strength, IIRC. Seems like its in the 2XXX pound range, maybe, IIRC. For this reason, prusiks are preferred to connect MA system, I believe, rather than a Gibbs with quick release pin.
 
I'm not digging the dogbone piece simply because it eliminates the ability to easily remove and retie your hitch. I'd rather see a something that could be removed when necessary without having to untie the double fisherman's knots. As it is this system is pretty much locked to your rope permanently, you lose the ability to quickly and easily remove and reset your hitch between trees. If you need to pull your rope through the tree then you only have one option of which direction you pull it. This could lead to major headaches in the wrong situation.
 
couldn't 2 biners be use to attach the the friction hitch?
Or is that some how going to mess with things?
For this, the eyes for the knots being turned side ways would probably help.
 
OK, I'm lost. Which one of these is closer to the final device?
 

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  • Thread Starter Thread Starter
  • #212
Ive been in the shop playing with this some, I don't understand the resistance to the dog bone. On the rope it works flawlessly and installing it only takes 20 seconds. Are you all realizing that it can be removed from the device by simply untying 1 stopper knot and aligning the end with the slot and pulling out??? Stopper knots don't seem all that hard to untie plus to me another big plus is you don't need spliced eyes so can buy cord in bulk and really easily customize the length literally as simply as tying a knot.

Dogbones here to stay;)


I think to fully understand the changes we are making you need to have used one. Notice DMC likes the idea, because he has felt how much smoother it makes the system...
 

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I sure can't wait to try this device out! I am lucky that Dave is my Climbing Mentor :) BTW, this is my first post here. Hello to you all...I will try to be a contributor here and not just a lurker.

Cody
 
Welcome to the House, Cody.
I'd say you are lucky indeed.
 
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  • #217
Good of you to post Cody. Im sure Dave will have a spare one of some configuration or other here soon;)
 
...I think to fully understand the changes we are making you need to have used one....

This is so true! There is no comparison in the way the HH preforms with the hitch directly attached at the top slot. Super smooth and compact! Very comparable to using a Hitch Climber Pulley but will switch from SRT to DdRT just like a Uni. The Hitch Hiker may not be fast at it but is midline attachable. I have been using mine without doing so because of how I have it setup. Remember there are lots of climbers using and quite happy with the way more expensive and less versatile Spiderjack that is not midline attachable. Climbing just requires a different game plan but it's not hard to do.

Dave

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Hey Cody.




Paul,

so long as its easy to untie, i am all for it. my concern was hard set knots. looks really good.

Tied cord is waay cheaper.
 
Paul.

What about using some sort of push button pin, with a custom collar on the opposite end to capture the other eye of the sling. No tying, just slip through your eyes on your hitch!
 
Brendon, anything that opens would have to be triple locking in order to be compliant for life support. Although the bolt with lock nut and washers in Dave's picture is closer to what I was thinking.
 
I would like to have one to purchase or try as soon as it may be possible. Looks like this device might work great for me on TDs
 
Duh! My bad.

I would just throw a biner through it. Not how you hung the original, just through the holes. Easy peasy.

Have you tried that?
 
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