Page 1 of 6

Heksu

Posted: Thu Jan 14, 2016 2:27 am
by heke
hi, here is side view of the ski I'm buiding.

size is 140/111/128,

I'm planing to have:
1. 760 triax glass
2. core made of Aspen
3. ud CF 50 mm wide
4. 200 g biax glass on the middle of ski app. 700 mm
5. 760 triax glass
6. 0,6 mm veneer

What would be good dimenssions for core thickness? tip 2 mm middle??


EDIT: the drwing don't work..

Anyway the wood part is 1620 mm long, tip part 740 mm, flat part 362 mm, tail part 518 mm.

Ski will be 190 cm long.

Posted: Thu Jan 14, 2016 8:18 am
by MontuckyMadman
Seems like a weird asym layup. Why do you want your compoistes this way?

Posted: Thu Jan 14, 2016 10:26 am
by heke
Dimenssions are from Völkl Katana. I love those skies.

Posted: Thu Jan 14, 2016 10:49 am
by MontuckyMadman
Katanas have random carbon and biax on top the core?
Weird.

Posted: Thu Jan 14, 2016 5:24 pm
by heke
I don't know how Katana is. This CF is something like 200 g. This is first skies I make..so I don't know. Some where I have to start.

For core thickness I'm planing to have something like 11 mm.

Posted: Thu Jan 14, 2016 9:42 pm
by MontuckyMadman
If you have no real reason for useing the extra composites than dont.
I dont think that biax will do anything but add weight.
What type of carbon 6k 12k 24k?
Standard modulas?
If you read the forums you will learn its best to have a symetrical layup about the core until you learn more abiut the materials and process you are dealing with.
KISS=keep it simple stupid

Posted: Thu Jan 14, 2016 10:43 pm
by heke
Hi & thänx,

I think in Europe we don't use 6k, 12k etc. I have not heard this before. The carbon is some thing like this I have some at home from time when I made kite boards.

http://www.fibreglast.com/product/Unidi ... _fiber_all

little heavier I think.

I try to make things simple as possible but as I don't know fully what to do .. :)

Posted: Fri Jan 15, 2016 4:19 am
by vinman
I'd just eliminate the carbon and the biax and just go with glass above and below your core. You could add a biax binding mat of about 18-20 inches for reinforcement there.

Like MM said, keep it simple for your first few builds. The fewer the layers/complexity the better. Get creative once you have your process down.

The 9.0 oz unit carbon would likely be too heavy/ crest too much stiffness.

Posted: Fri Jan 15, 2016 4:53 am
by heke
I'm race skier and I don't like soft skies. I'm afraid that the glass only will result too soft ski?

Posted: Fri Jan 15, 2016 5:45 am
by skidesmond
I hear you about being a racer and stiff skis, but that's not what you are building. You're building a big mountain ski. Totally different.

Go to the Volk site and read about the Katana. Looks like the Katanas may have changed their dims over time. The site says 143_112_132, slightly different. The new Katana has a 3-D profile. But I'm pretty sure the older versions were not.

As I'm sure all skibuilders have come to find out, making a ski with the same dims as a commercial ski doesn't guarantee you'll get the same feeling of your favorite commercial ski (setting expectations here). But you have to start somewhere.

I'd skip the CF. A little CF goes a long long way to adding stiffness. And not knowing the weight or if it's 6k, etc is also another learning curve to hurdle.

KISS principle is your friend for the few pairs or more.

Posted: Fri Jan 15, 2016 7:48 am
by chrislandy
heke wrote: I think in Europe we don't use 6k, 12k etc. I have not heard this before.
it's the number of fibres per tow so you'll often find them designated 200gsm 6k or 675gsm 12k etc

Posted: Fri Jan 15, 2016 9:34 am
by heke
skidesmond wrote:I hear you about being a racer and stiff skis, but that's not what you are building. You're building a big mountain ski. Totally different.

Go to the Volk site and read about the Katana. Looks like the Katanas may have changed their dims over time. The site says 143_112_132, slightly different. The new Katana has a 3-D profile. But I'm pretty sure the older versions were not.

As I'm sure all skibuilders have come to find out, making a ski with the same dims as a commercial ski doesn't guarantee you'll get the same feeling of your favorite commercial ski (setting expectations here). But you have to start somewhere.

I'd skip the CF. A little CF goes a long long way to adding stiffness. And not knowing the weight or if it's 6k, etc is also another learning curve to hurdle.

KISS principle is your friend for the few pairs or more.
I have a pair of Katana those are skies that are very good if slope is not in good condition or there is lot of soft snow etc.. Of couse those work best off piste. I know that it will not be the same, I will find out. Some where I have to start. CF is is like 6k and I was thinking to have a 2" wide strip on lenght of the ski.

Thanks for the comments!

Posted: Fri Jan 15, 2016 10:16 am
by chrismp
Well, if you must add the carbon then do it both above and below the core and maybe use a lighter fiberglass. There's plenty of info on this forum on the problems you get from asymetric layups. You definitely don't want such problems on your first pair.

Posted: Fri Jan 15, 2016 11:54 am
by skidesmond
I agree with the others, stick with the FG. If you're mind is set on using CF, use it on both sides like Chrismp suggests and I would go with maybe 1inch strip or less.
KISS principle is your friend.
btw - Nobody makes just 1 pair of skis :D Save the CF/money after you get some experience.

Posted: Fri Jan 15, 2016 8:47 pm
by heke
Thank you all.
I didn't find anything about asymmetric fibers could you please give me link or short explanation.

With CF I'm looking for more edge grip..torsion or what is correct word? I can live with out using CF😊. What about using 400 g and 760 g triax glass to have more torsion. Or 400 g triax in the middle of ski? Katana has race ski feeling it is slow to turn from edge to edge but even on ice edge grips well if edges are sharp.
Wood core will be 11 mm in middle. Made of aspen, it is like poplar.
It has been very cold this year..today -27C.