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Posted: Thu Oct 04, 2012 4:00 pm
by skidesmond
Nice write up.

For beveling sidewalls use a router or laminate trimmer. Lots of ways to use the router. You can buy certain bits to get the bevel you want. I use a straight bit and stick a 20 degree wedge (make the wedge any degree you like) to the bottom of the router plate. The bearing is on top of the bit. I run the router over the base and the bearing rides along the metal edge of the ski.

Layup speed- takes practice

Glad to see you're enjoying them... Smiley!

Posted: Thu Oct 04, 2012 4:33 pm
by More
Vinman wrote:congrats, your first pair looks better than mine, even though I loved them and they skied ok, they are really junk in comparison to my recent work.

Nice work.
Thanks man! Yeah, I'm sure I'll look back and laugh at this pair at some point - Plenty of low hanging fruit there regarding improvements.

Cheers for the tips Des, I've seen your wedged base router, it looks like the mutt's nuts.

Right, 4 hour drive ahead, I'm outa here!

Posted: Thu Oct 04, 2012 5:47 pm
by falls
shit, you'll have to buy a router :)

Posted: Wed Oct 17, 2012 6:25 pm
by More
:oops:

I've had my first really good screwup.

It seems I had too much epoxy on the base during layup and as a result the vds has squeeged (that should be a word) right outside the edges along a LOT of the length. tips are ok.

So, lesson learned, but does anyone know if the pair would be a complete throwaway without VDS on the lengthwise edge?

Just wondering whether to go to the effort of finishing the skis and getting someone to grind them etc etc, or if I just nail it to the wall marked "offerings to the god of speed".

Posted: Wed Oct 17, 2012 6:49 pm
by falls
people have made skis without vds and they have been ok.
if your edges were clean and blasted then chances are you will be ok.

Posted: Wed Oct 17, 2012 7:30 pm
by More
Awesome. We'll see I guess.

3 more weekends of lifts....

Posted: Wed Oct 17, 2012 7:41 pm
by twizzstyle
At worst, you may get some cracking/delam between the fiberglass and the edge. No big deal, you probably won't notice the difference. I've had the same thing happen when I've used really narrow VDS, now I stick to wider stuff just for more insurance :)

Posted: Wed Oct 17, 2012 8:08 pm
by More
:(
It was narrow stuff as well. ah well, guess I'm a little bit wiser now!

Posted: Wed Oct 17, 2012 8:12 pm
by More
Oh, and to make it worse, some of the kevlar I was playing around with migrated out as well. Now THAT is going to be a headache to cut. and could effect the ski I guess.

Posted: Thu Oct 18, 2012 3:19 pm
by More
sorry for the phone pics, but...

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I love the purple. need mroe colours. will have drag knife soon, bwhahaha.

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Stealth press - I hid the press in the back of the warehouse at work so I could run it during the day.

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Still a bit to do to them but you get the idea.

Will see how they hold up tomorrow!

Posted: Thu Oct 18, 2012 7:16 pm
by Less (antonym)
Yeah we should have guessed. We did the layup of the Kerf 176 with more resin then the first pair and 1/2 thickness VDS strips. The rubber definitely shifted but is still visible along the whole edge. Should have guessed that wetting out directly into the ski was going to mean more goop=more squeeze out and hence amplify this affect. Live and/to learn.

After a long wait, and a failed attempt I will finally get to test the second pair this weekend. As More alluded too, we are running out of days on the lift. One field closes this weekend and the other goes two weeks later.

Posted: Thu Oct 18, 2012 8:23 pm
by twizzstyle
Always a sad time of year :( Meanwhile, our forecasts are calling for the first snowfall of the winter at my mountain next week!

Posted: Sun Oct 21, 2012 5:30 pm
by More
Bit of a report on that pair... I got 1 day on them in lovely soft snow and then the weather packed up, and it's rained on the field now so that might be curtains for my NZ season. Looks like I'll catch some snow in the new year in Europe though.

Neither the lack of VDS and the kevlar moving around seems to have impacted performance, and no sign of delam (yet).

The most surprising thing about them is how soft they are. They're 3-11-3 with a flat zone 20cm back and 10cm forwards of boot centre. layup is
base,
2x 1" kevlar stringers (160g/m2),
24oz triax,
4 lengthwise 12k carbon tow, and an x pattern of 12k carbon tow about the contact points in the tip and tail,
core,
the same carbon arrangement,
24 oz glass
cotton
uhmw topsheet

I was expecting that carbon to make a pretty substantial impact on stiffness, but I'd say the ski is a very medium flex (although the pop back is great). And, as a big fella, medium flex is pretty soft for me. They're actually quite playful and I was really looking for more of a charging ski.

Now we've got a couple of different skis made with different core profiles I'm starting to get more of a feel for what different decisions will output.

btw, kevlar isn't as hard to cut as rumoured. remgrit blade in a jigsaw, no worries.

Posted: Mon Dec 10, 2012 4:58 pm
by More
So, I'm thinking about a pair to take to europe with me in Feburary.

How does this look?

The number that's hard to read in the middle there is camber, 5mm.
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Image

and some without dimensions so you can see it more clearly...
Image
Image

I'm thinking that the rocker might not be high enough... and if I increase it should I increase it in the tip turnup section (current 46mm rise over 90 length), or in the early rise section (currently 13mm over 260 length)? Havent settled on the core profile yet but will likely be bamboo, about 11.3mm underfoot, 3.2-3mm at the contact points and 1.4mm at the tips with 1.4mm base as tipspacers.

Then the next question is where do I mount a pair like this... I'm thinking a bit further forward than the standard 55% of running length. maybe 52.

Posted: Mon Dec 10, 2012 5:54 pm
by twizzstyle
I always put boot center at the waist of the sidecut. Whether that's the best place or not I don't know, but it has always given me a good performing ski. I don't follow any 55% rule of thumb, I just change the tip and tail widths until it "looks right". I do circular sidecut, so changing the tip and tail widths, with a fixed waist, determines where on the length of the ski the waist is.

It looks like you've done your sidecut with a spline. Is that a good idea? That means you might have a varying radius in your sidecut - maybe that doesn't matter.

I'm digging the "spoon" shape a lot of people are doing now with a short sidecut section, and long fat tips. I did that on my latest pair and they ski REALLY well! You are tapering your tip in quite a bit, how come?

Looks like you're gonna have some great skis for your trip!