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Sliders and pulleys vs Rings - Safety Tip

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edt
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Re: Sliders and pulleys vs Rings - Safety Tip

Postby edt » Sun Feb 19, 2012 4:02 am

Laughingman wrote:I'm totally guessing here but I would assume the power-lines accept about 90 percent of the riders weight/resistance.
more like 75% and the kite doesn't pull at the rider's weight all the time otherwise people would get thrown head over heads on their edge when they are cruising, more like 25% of the rider's weight and divide by 2 for both power lines so something like 10% of the rider's weight, so 7kg for an average rider

I wonder what happens if you wet the line and throw sand on it. Is it like instant destructo or does the sand work itself out? That's supposed to be where the slider beats the pulley.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Hansen Design » Sun Feb 19, 2012 4:53 am

Hi Pete:
Yes, you would definitely want to change the weight to test the components on the power line side of an active bridle depending on the geometry and location, etc. The 5kg in the illustration was based on sheeting and steering loads. We have a plan to measure the real-time loads on various kites but unfortunately have no data yet.
Cheers! :thumb:
Laughingman wrote:Hi Bill, thank you for all your input. It is people like you that honestly share information which inspires others to challenge the limits of their own understanding

I am no Engineer, or Physicist but sometimes I do perform rocket surgery... :)
As you stated, this test was designed for bar pressure, don't you think 5kg is a bit light for testing power-line bridle wear?
I'm totally guessing here but I would assume the power-lines accept about 90 percent of the riders weight/resistance. That would mean, imho that the testing weight should be 75kg or based on the configuration at least half of that in order to come to an average wear situation. What do you think?

Sincerely

Pete

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby knot_moving » Mon Feb 20, 2012 8:19 pm

Bill & Dimitri (and others in positions of influence for your brands),
The recall of F-One bars from last year because they were not (or not properly) anodized brings to light an important issue related to what we are talking about here.

These sliders (& pulleys they replace) on the bridle are safety critical items (like the F-one bar), in that if they break they are a single point failure that can lead to severe injury. I wonder if you can clarify what manufacturing standards are being used? How are they cast? What is the porosity? How are they anodized? Does the design spec call them out as being safety critical?

I am curious whether the kiting industry has matured to the point where we recognize the criticality of certain parts and are designing and procuring them using the appropriate standards?

As an aside - it seems like there almost should be a general call for all kiters to replace all their pulleys with either one like Ronstan Orbit (with safety line thru pulley axle) or something like these sliders. bridle line wear is pretty easy to spot, but corrosion/wear on a pulley axle can't be seen in many cases & it can let go at the worst possible time.

------
... just another run of the mill engineer who has to know something about critical safety items & who is a barely adequate kiteboarder that loves the sport and wants to treat it with the respect it deserves.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Hansen Design » Mon Feb 20, 2012 9:33 pm

Hi Knot:
Good question. I can only answer from my own experience.
I believe it has matured to the point where people recognize the 'criticality' but not necessarily to the point of appropriate standards in a true engineering sense.

I have been involved in production in SE Asia and Sri Lanka for over a dozen years and can say that there is a great deal of technology transfer and sharing of parts and designs at factories where multiple brands are produced. Some of it is surreptitious but to a greater extent it is a matter of expeditious convenience for the factory owners and brands which lack sufficient engineering staff. In 'theory' and marketing hype, each brand is entirely separate and closely controls it's construction, materials and designs, etc. but the reality is otherwise. Thus the barriers to entry are low and there are a lot of brands as a result with relatively low capitalization and start-up costs.

The following will appear to be a biased response but it is entirely honest, so those reading can take it with a 'grain of salt.' My current design client (Switch) in agreement with my advice and by their plan, did not enter the market until an exclusive production facility was developed where 100% of the production and engineering of the products from top to bottom are truly independent and controlled. This work along with pre-production testing of the kites took over a year and includes all the bar components and quik pump system components which were designed in-house complete with proprietary molds and tooling by their engineering staff in New Zealand. Clearly some components are procured from outside suppliers including the large inflate/deflate valves, pulleys and sliders and bridle lines. When outside components are involved, they are subjected to the same serious component testing as in-house parts which includes stress testing to an appropriate load safety factor as a part of the process before they are used. If a problem is found, Switch engineers (who actually exist and are professionally educated and experienced in the field) work closely with the supplier to insure the parts are safe and reliable. In the case of the sliders, which is a relatively simple solid SS casting, the solution is comprehensive testing before it makes it to production. That said, I will not say Switch designed or specified the casting and processing of this part. Only that it has been found after testing to be up to the task.
Cheers!
- Bill
knot_moving wrote:Bill & Dimitri (and others in positions of influence for your brands),
The recall of F-One bars from last year because they were not (or not properly) anodized brings to light an important issue related to what we are talking about here.

These sliders (& pulleys they replace) on the bridle are safety critical items (like the F-one bar), in that if they break they are a single point failure that can lead to severe injury. I wonder if you can clarify what manufacturing standards are being used? How are they cast? What is the porosity? How are they anodized? Does the design spec call them out as being safety critical?

I am curious whether the kiting industry has matured to the point where we recognize the criticality of certain parts and are designing and procuring them using the appropriate standards?

As an aside - it seems like there almost should be a general call for all kiters to replace all their pulleys with either one like Ronstan Orbit (with safety line thru pulley axle) or something like these sliders. bridle line wear is pretty easy to spot, but corrosion/wear on a pulley axle can't be seen in many cases & it can let go at the worst possible time.

------
... just another run of the mill engineer who has to know something about critical safety items & who is a barely adequate kiteboarder that loves the sport and wants to treat it with the respect it deserves.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Dimitri M » Tue Feb 21, 2012 4:15 am

Hello guys,
I know that few of your guys on this thread have pre-ordered the new "EPIC SLIDER METAL PULLEYS" through our ONLINE STORE. So I just want to let you know that the factory will ship these items on Friday the 24th of this month to the USA, and should have them ready to ship to you by Tuesday the 28th of February.
Once again thank you for your patience.
:thumb:

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Hansen Design » Wed Feb 22, 2012 5:47 am

Previously in this thread I posted the sliders would be available in the spare parts warehouse this week. US$3.60/pair.
http://switchkites.com/warehouse_comp/p ... ucts_id=82
Cheers!
:thumb: :thumb:
Sliders1a.jpg
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Re: Sliders and pulleys vs Rings - Safety Tip

Postby wytcap » Wed Feb 22, 2012 6:49 am

$3.60, nice job Switch!
Glad I did not pre order for $18.00!

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby McAbe » Wed Feb 22, 2012 4:01 pm

wytcap wrote:$3.60, nice job Switch!
Glad I did not pre order for $18.00!
About a month ago on this forum Dimitri offered sliders to anyone not happy with the rings, so I contacted him to get a pair of them, I kind of expected to get them for free as the rings that came with the kite are CRAP.
Instead after first trying hard to talk me out of ordering sliders (they are in no way better than the rings, only more sexy) he agreed to send me a pair for only 30$ +shipping.
Another fine example on what a terrific guy Mr D is.

Stupid me payed and guess what I got, a pair of new rings!?
Maybe a mistake, maybe not ( its a bit suspicious because he tried so hard to talk me out of ordering sliders), at least now he tells me that sliders is on the way :thumb:

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Dimitri M » Wed Feb 22, 2012 5:23 pm

About a month ago on this forum Dimitri offered sliders to anyone not happy with the rings, so I contacted him to get a pair of them, I kind of expected to get them for free as the rings that came with the kite are CRAP.
Instead after first trying hard to talk me out of ordering sliders (they are in no way better than the rings, only more sexy) he agreed to send me a pair for only 30$ +shipping.
Another fine example on what a terrific guy Mr D is.
Stupid me payed and guess what I got, a pair of new rings!?
Maybe a mistake, maybe not ( its a bit suspicious because he tried so hard to talk me out of ordering sliders), at least now he tells me that sliders is on the way :thumb:
Hello Mr. "McAbe". Yes, I finally found out 2 days ago by mistake with whom I was dealing with. It is always nice to put a face and name together.
I wish I could post your emails on this thread and on the other topics you have been posting, so people can have a better idea of what happen and get a better understanding of what you are all about. Again it was an honest mistake because of my surgery, I could not do all the shipping but asked my wife to help me by shipping you the pulleys, but some how she sent you the "O" rings by mistake. So few days later we sent you the new "Epic Sliders Metal Pulleys" for FREE because of our honest mistake. The first email I got from you was in January 17, 2012.
After a few back and forth emails, you told me that you were sorry about the entire deal. Then, you started posting negative things about me under the name "McAbe". (everything is on the emails).
Concerning talking you out of getting "Pulleys" to replace the "O" Rings you had on your used INFINITY v1 kite was correct, because you don't need pulleys, you can always get thicker lines to replace the worn ones. Why spend money on things that you don't need!!! Same thing happens with customers I get wanting to buy 3 or 4 EPIC kites. I talk them down to get 1 or maybe 2 kites and then go from there. What is wrong with this!!!
Now shipping to Brazil from the USA was $21 so $30 (pulleys and shipping) was a good deal. I wonder how much shipping other Kite companies charge for these pulleys and do they have the accessories attached to the pulleys, and what about their customer services????

P.S. At lease I hope you are enjoying your used INFINITY v1 that you bought from some one else. Again you mentioned that you did not want to mention your name on the private message I sent you couple days ago from the Kiteforum, because you were afraid I would not help you with your EPIC gear in the future. Once again you are wrong. EPIC customer always get continued service and support from us. This is what we are all about.
:thumb:
Last edited by Dimitri M on Wed Feb 22, 2012 7:31 pm, edited 1 time in total.

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Re: Sliders and pulleys vs Rings - Safety Tip

Postby Laughingman » Wed Feb 22, 2012 6:12 pm

Dimitri M wrote:
About a month ago on this forum Dimitri offered sliders to anyone not happy with the rings, so I contacted him to get a pair of them, I kind of expected to get them for free as the rings that came with the kite are CRAP.
Instead after first trying hard to talk me out of ordering sliders (they are in no way better than the rings, only more sexy) he agreed to send me a pair for only 30$ +shipping.
Another fine example on what a terrific guy Mr D is.
Stupid me payed and guess what I got, a pair of new rings!?
Maybe a mistake, maybe not ( its a bit suspicious because he tried so hard to talk me out of ordering sliders), at least now he tells me that sliders is on the way :thumb:
Hello Mr. "McAbe". Yes, I finally found out 2 days ago by mistake with whom I was dealing with. It is always nice to put a face and name together.
I wish I could post your emails on this thread and on the other topics you have been posting, so people can have a better idea of what happen and get a better understanding of what you are all about. Again it was an honest mistake because of my surgery, I could not do all the shipping but asked my wife to help me by shipping you the pulleys, but some how she sent you the "O" rings by mistake. So few days later we sent you the new pulleys for FREE because of our honest mistake.
After a few back and forth emails, you told me that you were sorry about the entire deal. Then, you started posting negative things about me under the name "McAbe". (everything is on the emails).
Concerning talking you out of getting "Pulleys" to replace the "O" Rings you had on your used INFINITY v1 kite was correct, because you don't need pulleys, you can always get thicker lines to replace the worn ones. Why spend money on things that you don't need!!! Same thing happens with customers I get wanting to buy 3 or 4 EPIC kites. I talk them down to get 1 or maybe 2 kites and then go from there. What is wrong with this!!!
Now shipping to Brazil from the USA was $21 so $30 (pulleys and shipping) was a good deal. I wonder how much shipping other Kite companies charge for these pulleys and do they have the accessories attached to the pulleys, and what about their customer services????

P.S. At lease I hope you are enjoying your used INFINITY v1 that you bought from some one else. Again you mentioned that you did not want to mention your name on the private message I sent you couple days ago from the Kiteforum, because you were afraid I would not help you with your EPIC gear in the future. Once again you are wrong. EPIC customer always get continued service and support from us. This is what we are all about.
:thumb:
All I can say to this is ...WOW, now that is customer service!


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