GS Race ski

[OAC]

Yeah, when laminating my first cores and watching all the epoxi pouring away leaving alot of "air space" between the wood stripes. An alternate approach was needed so to say. :-)

A reminder: epoxi IS plastic (not a glue), it forms(cures) itself when mixing resin and a hardener. It only bond with a surface and it won't penetrate

BTW, isn't it alot of oak in the core?

[dorabito]

(...) BTW, isn't it alot of oak in the core?

I put this amount for two reasons:
- I used very flexible and light poplar wood (it's function is almost exclusively filler, not structural) so I need some hard woods to have a good power transmission)
- I wanted to make sure the plate and binding screws would fit in the hard wood, and not in the poplar)

Also I'm not using the original layup, I'll use less fibers:

TOP SHEET
FIBERGLASS (triaxial, 750g/m2)
WOOD CORE and ABS SIDEWALLS
FIBERGLASS (triaxial, 750g/m2)
FIBERGLASS (triaxial, 750g/m2)
P-TEX BASE, STEEL EDGES and RUBBER FOIL (edge bonding and shock absorption)

[OAC]

You will be surprised of what fiberglass(and epoxi) do to reinforcement.

Keep up your enthusiasm!
Learning by doing!

[dorabito]

Hello everybody, I just wanted to ask for an opinion from you

Do you think I should add some carbon UD tape reinforcements ( http://www.boardbuildingsupply.eu/produ ... ucts_id=43 ) at the black parts of the picture



I was thinking in doing this and put them at that places for these reasons:

- I think (please correct me if I am wrong) that the tip and tail are very stressed parts because they are deformed artificially, so I think some carbon there would made them more durable (helping them to keep their curvature)
- I apply the same "theory" with the underfoot section, helping the ski to keep it's camber, and I also think that it will help to hold the binding's screws in the ski

Can I have your opinions please?

Thanks in advance

[MontuckyMadman]

dorito, your question may be well intentioned but until you resolve how you will press the ski, these details are worthless to your cause.

The carbon will add resiliency and pop but I doubt it helps with deformation. There are so many variables you still have yet to outline on the macro scale.

At this point I would advise you not to hope for a race worthy ski the first ones out of the gate. Make a few pairs and upgrade each time you go.

[dorabito]

-PRESS: I'll build my own clamp press with MDF (I can't afford an air pump, so I can't use a pneumatic press or a vacuum press). It'll cure at room temperature (I can't also afford a heated blanket)

- EXPERIENCE:PLEASE, STOP SAYING THAT IT WON'T WORK BECAUSE I DON'T HAVE ENOUGH EXPERIENCE. I am trying to do my best, and I am asking questions here because I don't have experience (if i had it, I won't be here). But please note that advices like "build a couple pairs first and then try it" or "don't expect to do it right at the first time" are COMPLETELY USELESS.

This ski will be my first one but it does not mean in anyway it will be a bad ski only for this reason

PD: I'm 16 years old, and my only earns come from working for my parents, and they said as this is my project, I have to pay for it; my parents only lends me the garage and generic tools. This is why I can't afford sophisticated equipment.

[dorabito]

dorito, your question may be well intentioned but until you resolve how you will press the ski, these details are worthless to your cause. (...)

My username isn't dorito, it is DORABITO

[MontuckyMadman]

listen dorito don't get your 16 yo panties in a twist before you have a chance to get them wet.

No one comes here with experience. That's why we are here.
I personally spent over a year reading damn near every post on this board before I bought anything. I suggest you do the same.

I don't think a clamp press will give you the results you are looking for.

How bout a fabric press? I will make you the fabric pieces for a nominal fee and you need to get a firehose and make your molds. Easy, peasy, japanesey.

[dorabito]

listen dorito don't get your 16 yo panties in a twist before you have a chance to get them wet.

No one comes here with experience. That's why we are here.
I personally spent over a year reading damn near every post on this board before I bought anything. I suggest you do the same.

I don't think a clamp press will give you the results you are looking for.

How bout a fabric press? I will make you the fabric pieces for a nominal fee and you need to get a firehose and make your molds. Easy, peasy, japanesey.

STOP CALLING ME DORITO.

PS:No me importa si te gusta o no. Construire este esqui como me de la gana, pondre fibra de carbono donde quiera, usare las capas que me apetezca y lo prensare como quiera.
Ah, and thank you very much for the offer of the fabric press, but I don't have money to pay a nominal fee, and you live very very far away from Spain, so it will be a problem; but thanks anyway.

Take care, dorabito

[krp8128]

[quote="dorabito"PS: I do not care if you like it or not. Construct this ski as I want, I would put carbon fiber everywhere, using layers prensare my mood and what you like.[/quote]


LMFAO, this shit keeps getting better. If you don't care, why ask for advice?

Read. Read again. if you don;t get it, ask some clarifying questions. Don;t come in here and expect to have every little question met with a polite answer. the basics of skibuilding, and then quite a bit more, are on this site in numerous places.

Face it, if you HAVE read everything that is here, yet you still ask these questions, you do not have very much woodworking, composites or "handy" skills and your first pair of skis will suck.

Do you have refrigerators in Spain? Then you can likely build a vacuum system for next to nothing. BTW, if cost is a factor, good luck building anything, this is not a cheap activity...

[dorabito]

PS: I do not care if you like it or not. Construct this ski as I want, I would put carbon fiber everywhere, using layers prensare my mood and what you like.

LMFAO, this shit keeps getting better. If you don't care, why ask for advice?

Read. Read again. if you don;t get it, ask some clarifying questions. Don;t come in here and expect to have every little question met with a polite answer. the basics of skibuilding, and then quite a bit more, are on this site in numerous places.

Face it, if you HAVE read everything that is here, yet you still ask these questions, you do not have very much woodworking, composites or "handy" skills and your first pair of skis will suck.

Do you have refrigerators in Spain? Then you can likely build a vacuum system for next to nothing. BTW, if cost is a factor, good luck building anything, this is not a cheap activity...

I asked for a solution, not for a "it is too difficult, you shouldn't do it". I've started my project. I have my design, I have my 1:1 scale mold and I have 2 cores ready to be shaped and profiled. I am not going to stop here just because I don't have experience; I 'll get experience by doing it, not for be sitting in front of a computer waiting for someone post something.
About the price, I can afford it, but keeping it simply.
About the fridge: Spain has refrigerators, but I just have no idea about building a vacuum press with a fridge. If you can explain me, I'll be very grateful.
About my handy skills: I can't find a reason to made horrible skis just because I am new on this. I can be new on this, but I can also be very careful and patient, so I could do a good first pair

PS. your translation isn't completely well

[twizzstyle]

The first pair of skis I ever made I did with a clamp press, virtually no experience working with fiberglass/resins, etc, with very little money, etc. They were entirely unskiable, I had them on the mountain once and they fell apart.

BUT it was a good experience and I don't regret it one bit, that was my first foot in the door. It wasn't until 4 or 5 years later that I built a pneumatic press and can make skiable skis now.

You'll have fun, you'll learn a lot (you learn a lot reading posts on here, but you learn the most by actually doing things with your hands, wasting money, and making mistakes - seriously. mistakes, while costly, are the best learning tools).

For your picture above - putting carbon strips in the tips won't do much, I wouldn't waste the carbon there. It won't have any problem holding shape after curing. The strips in the middle bit will help with screw retention, but if you really want it to stiffen the ski, extend the strips the entire length of the ski. Also if this is your first pair, I'd highly recommend doing the same number of layers of fiberglass (and carbon fiber for that matter) on the top of the core as you do the bottom, or else you might get camber changes after it cures.

[dorabito]

The first pair of skis I ever made I did with a clamp press, virtually no experience working with fiberglass/resins, etc, with very little money, etc. They were entirely unskiable, I had them on the mountain once and they fell apart.

BUT it was a good experience and I don't regret it one bit, that was my first foot in the door. It wasn't until 4 or 5 years later that I built a pneumatic press and can make skiable skis now.

You'll have fun, you'll learn a lot (you learn a lot reading posts on here, but you learn the most by actually doing things with your hands, wasting money, and making mistakes - seriously. mistakes, while costly, are the best learning tools).

For your picture above - putting carbon strips in the tips won't do much, I wouldn't waste the carbon there. It won't have any problem holding shape after curing. The strips in the middle bit will help with screw retention, but if you really want it to stiffen the ski, extend the strips the entire length of the ski. Also if this is your first pair, I'd highly recommend doing the same number of layers of fiberglass (and carbon fiber for that matter) on the top of the core as you do the bottom, or else you might get camber changes after it cures.

Thank you for your advices. As many people said, I should keep it simply by now, and I 'll. I won't use any CF, and now I just need to decide if I'll use layers or 2 layers of FB under and above the core

[twizzstyle]

Also, how are you profiling your core? You might have already said but I couldn't find it.

In my opinion, the core profile is the single most important thing in making a ski. You can do everything else perfectly, but if your core thickness is off by just a few mm, it will either ski like a 2x4, or it will be a floppy death trap. Remember, bending beam stiffness goes with the thickness cubed, so small differences in thickness make HUGE changes in stiffness.

[dorabito]

Also, how are you profiling your core? You might have already said but I couldn't find it.

In my opinion, the core profile is the single most important thing in making a ski. You can do everything else perfectly, but if your core thickness is off by just a few mm, it will either ski like a 2x4, or it will be a floppy death trap. Remember, bending beam stiffness goes with the thickness cubed, so small differences in thickness make HUGE changes in stiffness.

I have it stuck, but it isn't profiled by now. I am going to shape and profile it by numerical control cutting on an aeromodelling shop close to my house.
On the original post (the 1st one) there are the design, it is this:
Tip: 2mm.
Underfoot: 10mm.
Tail: 3mm.