Hi all
Aitor I'm from Spain, so please sorry my English, I may not explain it right or I may not understand his explanations.
Usually I build my own wooden surfboards, and I found this forum and I decided to make my own skis, by the way this forum is so good, congratulations.
But since I'm trying not to use the fiber in my surfboard and I would do the same with the skis. So I asked about the wooden skis made ​​with no fiber, wood and perhaps only the edges of the base metal and Ptex.
The construction technique is a multilayer sandwich plate diferents timber, placed in different directions and glued with poly-or glue.
I know these skis may not have the same quality as a standard ski, flexibility, torsion, and weight, and I think it might be a good ski powder snow, maybe not so good for hard pack skiing, but its interesting the research for environmental protection, using only wood, metal glue, and some plastic.
I found a craftsman in France, Jean Louis Tardy who builds wooden skis, and the truth is that look great.
What do you think about it?, I searched through the forum comments about this but have not found anything.
Fiberless skis
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Hepp veguis
I have been skiing on these for the last couple of winters.
http://www.tegsnas.com/ehandelskidor
Belive that they are made of 100 % wood. But these are for touring, not downhill.
A woodcore with veneers instead of fiberglas could work I guess. Natures own carbon fiber!
try it and write about it.
I have been skiing on these for the last couple of winters.
http://www.tegsnas.com/ehandelskidor
Belive that they are made of 100 % wood. But these are for touring, not downhill.
A woodcore with veneers instead of fiberglas could work I guess. Natures own carbon fiber!
try it and write about it.
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skidesmond
- Posts: 2337
- Joined: Tue Apr 07, 2009 3:26 pm
- Location: Western Mass, USA
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An all wood ski does work. I've made a couple pair and really like them. The skis I made are all mountain skis. The ski is great in most conditions. On real hard park I got some chatter because there's no damping material. I'm working on that problem and will post here when I resolve it.
I did a write on my blog this past season. Here's the link, go to the bottom for a critique of the all wood ski.
http://desmondcustomskis.blogspot.com/2 ... -made.html
I also posted info here at skibuilders about the all wood ski
http://www.skibuilders.com/phpBB2/viewt ... c&start=15.
I did a write on my blog this past season. Here's the link, go to the bottom for a critique of the all wood ski.
http://desmondcustomskis.blogspot.com/2 ... -made.html
I also posted info here at skibuilders about the all wood ski
http://www.skibuilders.com/phpBB2/viewt ... c&start=15.
I was looking for that post but couldn't find it. figured it would appear in a couple of posts if this tread started running.I also posted info here at skibuilders about the all wood ski
http://www.skibuilders.com/phpBB2/viewt ... c&start=15.
Finally i am doing a pair of wooden skis, but using only wood. So i will use a combination of bamboo layers instead of the triaxial fiber glass, the bamboo layer is 0,6 mm thickness, 2 layers 0º, 1 layer 45º and 1 layer -45º.
I do not know if I can do this simple reasoning, the fiber glass has a young modulus of 72 MPA and the bamboo 20 MPA, the fiber glass is 0,3 mm thickness , so if i use a combination of bamboo layers 3,5 times thicker could work like the fiber glass. What do you think?
4 layers , 2 of 0º, 1 of 45º and 1 of 45º, the total thickness is 2,4 mm, with the last reasoning the thickness needed should be 1,05 but the minimum thickness is 0,6 mm, maybe i could use just 1 layer 0º instead of 2 (that is a copy of the FB, 50% 0º +25% 45º+25% -45º).
I would like to use the Bambi´s spreadsheet to predict the ski flex. I change some settings, 50 oz/square yard in fabric weight, 1 on volume ratio, 700 kg density, young modulus axial 20 MPA, lateral Young Modulus is 2 MPA.
I think that the volume ratio would be 1 because wood is pure fiber and i use a value for the lateral young modulus of 2 MPA that i found online, but i am not sure that the final young modulus it is ok
What is your opinion?
I do not know if I can do this simple reasoning, the fiber glass has a young modulus of 72 MPA and the bamboo 20 MPA, the fiber glass is 0,3 mm thickness , so if i use a combination of bamboo layers 3,5 times thicker could work like the fiber glass. What do you think?
4 layers , 2 of 0º, 1 of 45º and 1 of 45º, the total thickness is 2,4 mm, with the last reasoning the thickness needed should be 1,05 but the minimum thickness is 0,6 mm, maybe i could use just 1 layer 0º instead of 2 (that is a copy of the FB, 50% 0º +25% 45º+25% -45º).
I would like to use the Bambi´s spreadsheet to predict the ski flex. I change some settings, 50 oz/square yard in fabric weight, 1 on volume ratio, 700 kg density, young modulus axial 20 MPA, lateral Young Modulus is 2 MPA.
I think that the volume ratio would be 1 because wood is pure fiber and i use a value for the lateral young modulus of 2 MPA that i found online, but i am not sure that the final young modulus it is ok
What is your opinion?
So basically you are making triaxial bamboo plywood?
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
That's right Vinman, triaxial bamboo plywood instead of triaxial fiberglass.
The triaxial FB thickness of a typical 22 oz fabric is 1mm, 0,7 mm FB + 0,3 mm resin, i think the resin is neglibible for calculation, so the real thickness is 0, 7 mm and Young Modulus of 72 MPA.
The triaxial Bamboo Plywood (aka BP) thickness is 2,4 mm , and YM of 20 MPA.
The density of FB is 2500 kg/m3 and BP 700 kg/m3.
So FB 0,7x72=20,4 MPA, BP 2,4x20=48 MPA, nearly the same resistance.
But not the weight, FB 1x2500=2500 Kg , BP 2,4x700=1680 kg, really lighter.
I know that the units are no ok, but i think the reasoning is clear.
And the combination of layers make the BP very resistant to tearing.
That´s my reasoning , but maybe it´s too simple and i am wrong or maybe forgetting something.
Only the first pair of skis can get me out of doubt
The triaxial FB thickness of a typical 22 oz fabric is 1mm, 0,7 mm FB + 0,3 mm resin, i think the resin is neglibible for calculation, so the real thickness is 0, 7 mm and Young Modulus of 72 MPA.
The triaxial Bamboo Plywood (aka BP) thickness is 2,4 mm , and YM of 20 MPA.
The density of FB is 2500 kg/m3 and BP 700 kg/m3.
So FB 0,7x72=20,4 MPA, BP 2,4x20=48 MPA, nearly the same resistance.
But not the weight, FB 1x2500=2500 Kg , BP 2,4x700=1680 kg, really lighter.
I know that the units are no ok, but i think the reasoning is clear.
And the combination of layers make the BP very resistant to tearing.
That´s my reasoning , but maybe it´s too simple and i am wrong or maybe forgetting something.
Only the first pair of skis can get me out of doubt
Finally i have decided to reply the icelantic scout skis, but instead camber i will build the skis with full rocker.
Short, fat, full rockered, good floatation, and plenty of fun.
The skis measurements 1473 length, 1100 running length, 140-110-130 width, 210 nose length, 163 tail length, sidecut radius 12000, nose anf tail height 46.
Short, fat, full rockered, good floatation, and plenty of fun.
The skis measurements 1473 length, 1100 running length, 140-110-130 width, 210 nose length, 163 tail length, sidecut radius 12000, nose anf tail height 46.
letting me hang like that??!
Pleasantly reading along eating my dinner then suddenly stop! Last post dec 2012 
How did it go?
Cool project
How did it go?
Cool project
Hi Halfdan
Last year i became father (the very best project ever) , so my projects were slowed but not stopped, i finished my press, i am testing glues, especially between the wood and the base, i have tried with polyurethane glue but does not work well, i will try with epoxy glue, not epoxy resin.
I discover that the bamboo layers are not as stiff than the solid bambu, maybe the cut system, the unrolled wood is less stiff, i did a test, i glued 10 bamboo layers of 0,5 mm thickness , and compare with a 5 mm piece of solid bamboo, and upssss, it bend easier , much easier, so i am redesigning the sandwich, maybe i increase the total thickness, or maybe i will cut 1 mm layers of solid bamboo.
Thanks for your good words.
Last year i became father (the very best project ever) , so my projects were slowed but not stopped, i finished my press, i am testing glues, especially between the wood and the base, i have tried with polyurethane glue but does not work well, i will try with epoxy glue, not epoxy resin.
I discover that the bamboo layers are not as stiff than the solid bambu, maybe the cut system, the unrolled wood is less stiff, i did a test, i glued 10 bamboo layers of 0,5 mm thickness , and compare with a 5 mm piece of solid bamboo, and upssss, it bend easier , much easier, so i am redesigning the sandwich, maybe i increase the total thickness, or maybe i will cut 1 mm layers of solid bamboo.
Thanks for your good words.