DXF for profiling crib?

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a.badner
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Post by a.badner »

twizzstyle wrote:
You said a "constant taper gives more pop", how so? It will change the bending characteristics, and create a stiffer ski (compared to a soft-curved profile). Whether or not that equates to more pop though I'm not sure.
As you said, it changes the bending characteristics.

With a plateau, most of the bending will happen where the tapering ends.
so causes more of a V shaped bend. with a V you wont get as much pop because the reflex of the bent tip/tail will smack the ground.

think of it like a rat trap. it bends into a V and then hit the rat full force going straight down.

And with a constant taper it bends more into a C shape. When it reflexes, it will hit the ground around/at a 45 degree, giving it more forward push/pop :)

i wish i had nice elaborate drawing like falls. but the word analogies are the best things i can come up with. ill try drawing somthing.

:)

andlonger ski wouldnt be MUCH softer. just lest durable at the tips and tail :)
Rowen
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Post by Rowen »

And enter Endre Hals and the Ski Flex Index.

It would be really interesting to keep characteristics of the skis the same and just try different flex profiles, from gentle arcs to some of the real wobbly looking curves. It would also be very interesting to see what effect 1", 2" or full carbon fiber did to those curves.
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MontuckyMadman
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Post by MontuckyMadman »

a.badner wrote: With a plateau, most of the bending will happen where the tapering ends.
so causes more of a V shaped bend. with a V you wont get as much pop because the reflex of the bent tip/tail will smack the ground.

think of it like a rat trap. it bends into a V and then hit the rat full force going straight down.

And with a constant taper it bends more into a C shape. When it reflexes, it will hit the ground around/at a 45 degree, giving it more forward push/pop :)
Thats an interesting theory but I think if you look at most park skis you may see a different core profile/flex.


Look at endres flex profile charts. I don't ski park but I always thought the design was much more of a short profile to a plateau instead of a constant taper.

I always thought the idea was to more quickly transfer energy to the tip and tail via that stiff area underfoot than have a rounder flex. Yes the skis are softer but the power/flex dynamic is different.

Rowen you guys make a park ski right? how is your core profile different than you all mountain shapes?
Rowen
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Post by Rowen »

[/quote]
Rowen you guys make a park ski right? how is your core profile different than you all mountain shapes?[/quote]

We used an adjustable crib our first year and tried many MANY different profiles across the range of prototype skis we made. It was a lot of work to get the information, and I hope that you can understand that I'd be crossing the line if I were to give that information away. Besides, its all specific to our core material.

Check out Endre's ski flex curves, theres info in there that one could correlate with just a basic measurement of ski (and for the most-part, core) thickness. I might be mistaken, but I even believe someone on TGR posted a bunch of ski thickness measurements in info thread. Data may be a few years old, but it might be useful if you're willing to crunch some numbers. Only other way I'd see is to just try it out!
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MontuckyMadman
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Post by MontuckyMadman »

wasn't asking for details was just asking you to potential corroborate my statement of plateau vs continual taper from center, with relation to the flex pattern the OP was referring to.
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falls
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Post by falls »

http://www.youtube.com/watch?v=rEGjSFYc ... ata_player
Good vid on line afterbang core shape. A long constant thickness back towards centre will bring the hinge point of the flex to that junction. This type of thing is good for nose/tail presses and butters. But I think would lead to a fair bit of chatter at higher speeds. Constant taper gives a more rounded flex (like the C shape) you described earlier.
Don't wait up, I'm off to kill Summer....
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a.badner
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Post by a.badner »

falls wrote:http://www.youtube.com/watch?v=rEGjSFYc ... ata_player
Good vid on line afterbang core shape. A long constant thickness back towards centre will bring the hinge point of the flex to that junction. This type of thing is good for nose/tail presses and butters. But I think would lead to a fair bit of chatter at higher speeds. Constant taper gives a more rounded flex (like the C shape) you described earlier.
didnt need to tell me. but thanks anyways for the vid. worth watching.

plus, chatter only really happens on packed snow, corn and ice. in the park, on moguls and in deep snow chatter isnt much of a problem to be worried about.
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