Bulldog Bone

Copper is a heat sink and will transfer it to other metals but is not so good at heat release to the air. That is why it is used on the bottom of cooking pots. Aluminum is much better at releasing heat to air and is why it is used on all sorts of cooling fins.
 
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  • #302
The brass used in the adjustable Bulldog Bone bollard is alloy 360. Here is a brief description of this material.
" Free machining brass , produced from a combination of copper and zinc, has the highest machinability of all copper alloys, and is the standard against which all the others are compared to. 360 Brass, known for its strength and resistance to corrosion with properties closely resembling that of steel, is one of the most popular copper alloys used today. 360 Brass can be precision machined easily."
 
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  • #305
Aaron is the only one using it, but it allows him to run his arrowfrog in the Bone. Personally I prefer the adjustable Bone with the brass bollard, because of the nice smooth release.
 
No complaints about the new adjustable arm from me, hardly any wear in 6+ months of use.

Any reason not to trim the bottom arm a bit Gordon?
 
It seems like you could trim about an inch off of the bottom arm with no effect to performace.
 
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  • #309
Ah, you must mean on the outboard end. Yes you could, but I added the "hook" as one user left the gate open there, and while the Bone still functions with the gates open, it adds strength to the friction link if that should happen to someone else.
 
I have made an elongated bollard in the past for the Bone, made from aluminum 7075, that is more lozenge shaped, with rounded ends. There is a recent picture posted at http://www.treebuzz.com/forum/threads/compact-bulldog-bone.28246/page-194, that the climber who has been using it for over a year, put up in the Bulldog Bone thread, showing his two Bones on two lines. The Lozenge shaped bollard is short enough so that you can turn it around inside the top arm, to the other side if one side wears too much.

Gordon, why didn'r you make it standard bollard? any downside to this?
 
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  • #314
Max, there was a heavy climber who was having slippage, so I suggested he try the elongated bollard.
There is no down side I can see, except perhaps it does not release as smoothly. He loves it.
How does your on the knee modification release? Perhaps watch out for wearing a sharp leading edge?
 
Errare humanum est :)


"From a longer quote as follows: "Errare (Errasse) humanum est, sed in errare (errore) perseverare diabolicum.", attributed to Seneca, which translates to: "To err is human, but to persist in error (out of pride) is diabolical"

good point sir.
thanks for that
.
 
Max, there was a heavy climber who was having slippage, so I suggested he try the elongated bollard.
There is no down side I can see, except perhaps it does not release as smoothly. He loves it.
How does your on the knee modification release? Perhaps watch out for wearing a sharp leading edge?

Descend is really smooth even on a wet rope, As for the sharp front edge... It's not even that sharp and could be made more round. I'd like to make it out of titan but don't have means to work with this material.


"From a longer quote as follows: "Errare (Errasse) humanum est, sed in errare (errore) perseverare diabolicum.", attributed to Seneca, which translates to: "To err is human, but to persist in error (out of pride) is diabolical"

good point sir.
thanks for that
.

Seneca - is steep! :)
 
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  • #321
<iframe width="560" height="315" src="https://www.youtube.com/embed/LLYneZ6-H8A" frameborder="0" allowfullscreen></iframe>
Thought I would keep this thread alive and plug the Bone with this demo video from almost two years ago.
 
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  • #323
Here it is. While this Bone has been called the XL version, and is a dedicated Vortex Bone because of a wider spacing in the upper arm and a shorter pivot length, It actually is smaller because of the shorter upper arm. I think maybe I should call it the stubby Bone : ) notice the stainless steel and nylon standoff at the top of the spine, this is to keep the short top arm from collapsing too much on ascent.

EVgykQA.jpg
 
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  • #325
Here is an email I have received from an adjustable Bulldog Bone user. Do not try to adjust the bollard while weighted.

"Hy Gordon,

I learned something important about the new adjustable toparm today!
Don't adjust it when hanging on the Bdb, because that way you'll screw out not only the bolt but also the nut. When adjusting the bone, the nut has to move (in order to keep it in place). I didn't realize that and as my bone kept slipping I tried to adjust it... until the bolt was out of the bollard!
Nothing happened, I just wanted to let you know to keep an eye on the position of the nut!
Kevin"
 
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