b2therye's ski's

[Richuk]

An additional layer of fiberglass will add 10% to the final pull out strength.

Kevlar is difficult to process and costly. The matrix won't react well to drilling. Goodluck man.

[knightsofnii]

your core looks awfully thick at the tips... and obviously quite stiff, just assumptions from looking at that photo.

[skidesmond]

your core looks awfully thick at the tips... and obviously quite stiff, just assumptions from looking at that photo.

I agree, looks a bit thick. Could just be the angle of the pic. You want the entire tip area/length to be the same thickness. I'd double check the thickness, you can always belt sand it down some if need be.

[b2therye]

Update:

Well, making the cores with a close tolerance on to the template didn't work out. I completely forgot to make an allowance for the steel edge!

I added some off cuts to the side of the cores.



Then I used a hand router to profile them to the current shape



I wasn't happy with how much the cores weren't conforming to the mold shape so I decided to cut the tip and tail off and i was planning on using the offcuts as spacers.



I measured the core again and it was way too thick. originally I made the core 2.5-15-2.5 but then decided 15 was too thick, but because of the way we were planing it i could only take material off the middle making it 2.5-12-2.5; now that i've cut the tip and tail off it makes it 6-12-6.

I'm now going to get some tip and tail spacers and re-plane the core ill make it 2-12-2

So then I pulled my bases off the template. let me tell you kids, melamine and double sided tape is a bad mix.



I'll have to do a nice base grind after its molded

So instead of trying to rush I finished the weekend cutting up all my composite:

Double Bias Carbon Fibre



Uni Carbon Fibre



Plain Weave Carbon/Kevlar



As for the binding issue, i've ordered some quiver killers and ill do a little test with the lamination off-cuts.

That's me for a couple of weeks; its starting to get chilly here in Sydney; better stay on track or ill be riding rentals!

Thanks for all the comments guys, your help is invaluable!

[gozaimaas]

Dude. You have to assume your first pair wont be up to skiing. Its a fact of ski building unfortunately. So hang up the carbon and aramid and save it for when you get your process down. Get some 757gsm triax fibreglass to play with in the mean time

And as you have worked out the core profile should be the length of the effective edge with tip and tail being around 2mm all the way.

[sammer]

Dude. You have to assume your first pair wont be up to skiing. Its a fact of ski building unfortunately.
So hang up the carbon and aramid and save it for when you get your process down. Get some 757gsm triax fibreglass to play with in the mean time

I have to second goz on this.
It's been repeated many, many, many times.
Unless you have deep pockets filled with cash and don't mind throwing some of it away.

Also get that mdf off the bottoms of your base, use a scraper or a sander or whatever.
If you leave that there it will imprint and your skis will be garbage.
It will not grind out after pressing!

I use three pieces of double sided tape to hold base to template when cutting it. (each are about 1.5" sq) Same in the mold.

sam

[skidesmond]

What's the weight on the CF materials? That stuff becomes amazingly rigid. I agree with Goz and Sammer. Keep it simple until you get all the kinks worked out.

[skimann20]

Is the front of the edge exposed? You need to have that tucked behind something or you run the chance of it ripping right out. Or are you going to wrap the tip with a second piece? Also, it is a must that you grind/sand that material off the base. It will "print" into your base and you'll never be able to get it off.

[sammer]

Is the front of the edge exposed?
You need to have that tucked behind something or you run the chance of it ripping right out. Good call skimann20 I missed that

Or are you going to wrap the tip with a second piece? Not the best idea
Also, it is a must that you grind/sand that material off the base. It will "print" into your base and you'll never be able to get it off. Yup covered that.

b2therye, I think it might be worth another read thru of a few older build logs.
I don't imagine materials are cheap in oz, and it would be a waste to throw it away on what you've started here.


Also what is the black material on your mold?

sam

[MadRussian]

Or are you going to wrap the tip with a second piece? Not the best idea

don't want to hijack the thread.....this good moment to ask. Why you think so?
I think it's good option to use 4 sections edges

to OP you must have high expectations and high confidence in your process to use so many different expensive materials on the first pair.
IMHOfirst need to build basic model and then start modify the layup one component of the time

[sammer]

MR... Ive done a 4 piece edge before and it turned out pretty good.
The way I read the question was another piece of base, which would not be a good idea.
4 piece edge would solve his problem but would be a pretty tight radius from the look of it.

sam

[skimann20]

I was referring to a four piece edge. so you were both right.
yes that radius would be next to impossible to get a good fit with a single edge, a 4 piece is a must.

[b2therye]

Yeah, i've got some tip/tail spacers on the way and now the wood core will only run the effective edge. 2 - 12 - 2

I've seen a Moment Skis, Crown Skis only run edge on the sides not on the tip, I know it is possible to be damaged but i'm willing to take the risk, what do you mean by tucked?

[gozaimaas]

What you need to do is make the base material flush with the outside of the edge instead of having the edge protruding like you have there. Its no big deal for your first pair though, just linish it back when you are finishing them.

[MadRussian]

, what do you mean by tucked?

you need to start reading