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Sliders and pulleys vs Rings - Safety Tip

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faklord
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Re: Sliders and pulleys vs Rings - Safety Tip

Postby faklord » Tue Feb 14, 2012 10:20 pm

Bill (or anybody else),
Can you advise as to a source of the stainless sliders (as shown in your original post)?

I know tomatkins asked the same question, but it seemed to get lost in the noise.

Thanks

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Hansen Design » Tue Feb 14, 2012 11:35 pm

Faklord/TomAtkins:
They are presently being added to and will be available for order on the Switch Warehouse Components site http://switchkites.com/warehouse_comp/index.php in about one week. At the moment I do not know of any over-the-counter suppliers as they are an OEM part but I suspect they will eventually find their way into retail shops.
Cheers!
faklord wrote:Bill (or anybody else),
Can you advise as to a source of the stainless sliders (as shown in your original post)?
I know tomatkins asked the same question, but it seemed to get lost in the noise.
Thanks

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kitenaked
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Re: Sliders and pulleys vs Rings - Safety Tip

Postby kitenaked » Wed Feb 15, 2012 12:39 am

ZigZag wrote:Good idea, Tom! I can get hold of thimbles, but can't source sliders.

Question for Bill Hansen:
Instead of using round section line in a round section slider that looks like this

Round section.gif


why not use a flat braid in a rectangular section slider, that looks like this?

Square section.gif


On high modulus material like Dyneema, there is very little stretching under tension, and the material on the inside of the neutral plane gets compressed and buckles. It is the buckling of the line that leads to the thickening and fuzzy appearance. The flat braid has a shorter distance from the neutral plane to the outside surface, so the compressive stresses are smaller, and therefore there will be less buckling.




Nice idea for strength, however there is more surface area in contact and may cause issues with wear and reduced free movement of the slider and the bridle line due to the additional friction and contact area.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby edt » Wed Feb 15, 2012 4:42 am

kitenaked wrote:Nice idea for strength, however there is more surface area in contact and may cause issues with wear and reduced free movement of the slider and the bridle line due to the additional friction and contact area.


Friction is not proportional to contact area but to the normal force, and there will be no additional wear. Put another way, because the normal force is more spread out, on a strap, there is less force on the strap per area, so even tho you have more area it is exactly balanced by less normal force per area so the wear is exactly the same only more spread out. And since it reduces shear, seems like a win right, but . . . anyplace I have straps in my equipment I will occasionally find them folding in half. Not a problem on a harness but a folded strap could lead to failure on a slider. I also notice that if my straps for whatever reason come in kitty-corner to an adjustment loop, the edges wear out really fast.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby ronnie » Wed Feb 15, 2012 11:18 am

faklord wrote:Bill (or anybody else),
Can you advise as to a source of the stainless sliders (as shown in your original post)?

I know tomatkins asked the same question, but it seemed to get lost in the noise.

Thanks


Item 9 is similar

http://www.cabrinhakites.com/crossbow-2 ... parts.html

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby tomatkins » Wed Feb 15, 2012 3:47 pm

Ronnie,

Thanks...looks like $33. plus $15 shipping for a pair... $48....YIKES! I don't need the sewn on loops. Hopefully, Bill Hansen can beat that price. I know, I know...economy of scale issues...your life depends on it...worth the price, if you look at it that way.

.............

Also, here is picture of the Naish slider that I mentioned as being the first use of such an item.
Attachments
Naish trim line pulley.png
slider for sale.png

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edt
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Re: Sliders and pulleys vs Rings - Safety Tip

Postby edt » Wed Feb 15, 2012 6:21 pm

tomatkins wrote:Thanks...looks like $33. plus $15 shipping for a pair... $48....YIKES! .


what is wrong with the antal 7mm aluminum sliders, they can be bought at any sailing store, $12 for per slider

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby flyingweasel » Thu Feb 16, 2012 1:28 am

Great pitch Hansen Aerosports :naughty: ...cant wait to see the price!!!


:roll: :roll: :roll:

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby tomatkins » Thu Feb 16, 2012 4:02 am

edt wrote:
tomatkins wrote:Thanks...looks like $33. plus $15 shipping for a pair... $48....YIKES! .


what is wrong with the antal 7mm aluminum sliders, they can be bought at any sailing store, $12 for per slider


Answer: Salt water

That is why they went to stainless steel for the bar hole inserts. The salt water corrodes the aluminum with a type one or type two pitting corrosion (maybe both types) and in time this causes a rough surface... which is the last thing you want for any kind of line or rope to slide against.

Did the aluminum stay shiney and smooth, when only used in fresh water? If so, then, maybe aluminum sliders would be OK for fresh water use only.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby alexeyga » Thu Feb 16, 2012 5:33 am

tomatkins wrote:
edt wrote:
tomatkins wrote:Thanks...looks like $33. plus $15 shipping for a pair... $48....YIKES! .


what is wrong with the antal 7mm aluminum sliders, they can be bought at any sailing store, $12 for per slider


Answer: Salt water

That is why they went to stainless steel for the bar hole inserts. The salt water corrodes the aluminum with a type one or type two pitting corrosion (maybe both types) and in time this causes a rough surface... which is the last thing you want for any kind of line or rope to slide against.

Did the aluminum stay shiney and smooth, when only used in fresh water? If so, then, maybe aluminum sliders would be OK for fresh water use only.


Dude, if you're so knowledgeable, why don't you dig out what kind of material is used to coat the Titanium rings on high-end fishing poles and enlighten us?

That being said, these Antal/Gin rings:

Image

will most likely outlast the tear-trop-type sliders:

Image

for the simple reason that being a ring, you can rotate it every so often - thus, evening out the wear. Doesn't matter what the slider is made of, it will wear out with time as sand gets trapped in the bridle and acts as sand-paper. So in long-term a stainless still tear-trop-type slider will get groovy and destroy the bridle way faster than an aluminum Antal ring.

In terms of safety however, a tear-trop-type slider is a safer solution due to it's shape and smaller footprint. Theoretically, with these you have a lot less chances for things to get wrapped around and stuck than with larger/rounder Antal rings.

And like somebody has suggested, pulley/ring/slider-less kites with bridles do exist, so instead of worrying you might just take some time to check these kites out. Kite's evolution is a perfect example of the theory that everything works in a circle. The whole bow-revolution after 6 years came back down to C-kites with bridles - go figure why.


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