Kong Double Ascender

[Burnham]

Very well put, Jack!

 

[Gord]

here's my contribution similar to spydy's but w/ webbing and central V not an attatchment point. it actually pulls the ropes together if loaded. this is three wraps, four may be appropriate also.

 

[Gord]

other side.

 

[Gord]

under load. this is what I would use. imo it's the only one that is simple enough to tie for each ascent.

edit: glen if this is what you were describing my apologies.

 

[jkrueger]

Re: A symmetrical Kong Double Ascender

Originally posted by TreeCo
I've gone back and looked at the photos of the Kong double ascender and I think a minor change in the way it is built would make it a much better product. I'm suggesting it has a serious design flaw because the way it is built it is impossible to capture both ropes with a carabineer on both sides at the same time. It's also impossible to do it with two carabineers.

If you notice the red and the blue sides are mirror images of each other. The ascender as a whole is not symmetrical. If the red and blue side were made identical except for color...and the blue side was on the opposite side of the ascender from the red.....over the other handle........the carabineer holes would not line up and it would be possible to capture the rope on each side with a separate carabineer.

I believe the change I'm suggesting would improve the Kong double ascender and also work well for the purposes we've discussed in this thread.

Kong might not even need to manufacture that mirrored imaged ascender half any longer.

Dan Nelson

I think all that needs to be done is; to elongate the hole to accomodate a biner passing through. A downward elongation with maybe a 2deg off set to maintain material integrity.

Jack

 

[jkrueger]

Re: Re: Re: A symmetrical Kong Double Ascender

Originally posted by TreeCo
I was thinking that the double ascender is to wide for one biner to pass through all four holes....two holes in each ascender. Each ascender needs to have it's rope captured. One biner that catches the center two holes but does not catch the two outside holes I don't believe captures the rope correctly on either side.

Dan

You are probably right there. How about elogation and splaying out the outer 2 holes and give the inside a bit more room for ease of acceptance of the biner? If Kong wont we will have to machine and test with drop loads?

Jack

 

[glens]

Originally posted by Gord
glen if this is what you were describing my apologies.

That's precisely what I'd described, Gordon Wood (can't get that out of my noodle since the other day...), though not with strap.  No need for apology.  Indeed, I thank you for supplying the visual.  Will the ascender properly tend strap hitch as it will with cord?

I think that instead of modifying the ascender configuration, there needs only to be a minor additional part.  Go to your farm supply store and see if you can't find a hitch pin and keeper that fits.  Then think in terms of making one out of aluminum and tethering the pin and keeper to the unit so they don't get separated in your kit bag.

Glen

 

[TheTreeSpyder]

i think the lack of dimension in the flat webbing would make it not tend up as easily, might even jam in cam on some unlucky day?

You can grab the center to saddle (where the frenchys might pull into VT's); or not grab center; just use the 2 list of Frenchy coils.

For firmer base for tending up, might not grab center, take each leg and throw a half hitch under each Frenchy so they would look more like 5/1 Distel or Schwab (depending on direction of turn going against or with same direction as Frenchy coil part respectively) only held by 1 leg each (not grabbing center of cord to bring to saddle).

Or, something like that...
:alien:

 

[Tree Machine]

Agreed 100%. That's precisely the problem we're trying to solve in presenting this to Kong. In my 'letter to Kong', if you look closely, I have shaven away the two outer 'holes' and have extended up the the two inner shell parts that slap up adjacent to each other. It is through this new, central extension will situate between the ropes and will contain a hole into which a biner will just fit.

Another approach to that hole is to elongate it slightly and place it on diagonal. In normal use the biner would then be down, and slightly away, not touching the ropes. In the case of a 'fall', the biner would be pulled up and into the ropes, creating friction on them in addition to the backup hitch. This is only theoretical.

 

[TheTreeSpyder]

Elongated holes have a short axis that could get bound and leveraged easier if any twisting etc. happened i think, maybe inverted teardrop? For walking the line between strength and openness?

 

[glens]

It's entirely possible that Kong will not want to tool up for what amounts to a different design.  And I don't even think it's necessary.  See the attached image.

Glen

 

[jkrueger]

Originally posted by glens
It's entirely possible that Kong will not want to tool up for what amounts to a different design.  And I don't even think it's necessary.  See the attached image.

Glen

Good idea. BTW: has anyone been trying this all out. I havn't, no time to sneak away, are the hitches sliding OK going up. Or is there a problem like Jim Roach pointed out.

Jack

 

[glens]

In my informal tests with the hitch (although not with a dual ascender), it slides up like a tab of butter on a hot ear of corn, even after loading (which would never happen in normal use, right?).

Regarding the alignment of the ropes, the hitch as shown will indeed allow the ropes to slide toward the cams but the ropes will not be able to fall out of the "tunnels" since the ropes are tethered to each other each side of the divider.  The only thing that would change in terms of cam action should be that the rope might at times have more wrap on the cam.  If it's not loaded and you're advancing the ascender that shouldn't be much of a problem and it will certainly assist camming/locking action when loading the assembly in such instances.

Glen

 

[jkrueger]

Originally posted by glens
In my informal tests with the hitch (although not with a dual ascender), it slides up like a tab of butter on a hot ear of corn, even after loading (which would never happen in normal use, right?).

Regarding the alignment of the ropes, the hitch as shown will indeed allow the ropes to slide toward the cams but the ropes will not be able to fall out of the "tunnels" since the ropes are tethered to each other each side of the divider.  The only thing that would change in terms of cam action should be that the rope might at times have more wrap on the cam.  If it's not loaded and you're advancing the ascender that shouldn't be much of a problem and it will certainly assist camming/locking action when loading the assembly in such instances.

Glen

I like the idea and I think I'll end up machining the holes. Since I do have experience in material strength and design I'll make a jig that others may use or copy. If there is interest it can be cast with machine shop plastics used for such limited run set setups.

Or just go as it is. I asked Big John the other day how he felt working of the Kong without any friction hitch back up, he said, "... I set it to not fail". He really thinks ahead in ways that are valid and for most not doable.

Jack

 

[jkrueger]

Here is the set up I'm using, chosen out of all the good work everyone did.

Jack

 

[jkrueger]

Shot of it if cams failed. And showing pulley for working off it ont the way up.

Jack

 

[glens]

That's cool, Jack.  Thanks for the feedback/followup.

It also works with only one cam "failed", right?

Glen

 

[NickfromWI]

Ok, heres the photo of the Chucky V backup prusik that I made for the Tree Machine. I think it'll work perfectly for what we're looking for.

love
nick

 

[NickfromWI]

Here's how I tied it. Just wrapped it up 4 or 5 times. Both 4 or 5 wraps worked perfectly. 4 was easier to push up (it broke easier) but 5 locked up quicker (the 4 wraps slid for half an inch before locking, but always locked).

love
nick

 

[NickfromWI]

Here's what it looks like when you pull down on it.