Twizz 2011/2012

Document your personal work here. Show photos, movies, and share your secrets.

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twizzstyle
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Location: Kenmore, Wa USA

Post by twizzstyle »

When I'm not flying airplanes or building skis, I build crap like this...

http://static.ak.fbcdn.net/rsrc.php/v1/ ... 29268&ev=0

It's a good thing I've got awesome neighbors who are equally as project-bound. Instead of complaining about the noise, they come over to check out the awesomeness. :D
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Brazen
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Post by Brazen »

When I was 10 I built a bazooka out of pipe, an end cap, a golf ball and a 3:1 mixture of bleach/brake fluid. It shot through 2 walls and a TV. I also received a broken collarbone from the kick. Grandpa always let me do whatever I wanted in the garage, but I think grandma took a chunk out of his ass. I was relegated to fixing a broken gas meter from scratch with a sore arm and butt for the next week. That was my summer :) OMG that has to go in an ultralight!!!
"86% of the time it works 100% of the time".
OAC
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Post by OAC »

@Brazen: Haha! Your stories get better and better! :-)

@Twizz: My firefox just shows a black background...is it your Jet engine?
twizzstyle
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Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

OAC wrote:
@Twizz: My firefox just shows a black background...is it your Jet engine?
Yes, you've seen it on Facebook.
skidesmond
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Post by skidesmond »

Brazen wrote:When I was 10 I built a bazooka out of pipe, an end cap, a golf ball and a 3:1 mixture of bleach/brake fluid. It shot through 2 walls and a TV. I also received a broken collarbone from the kick. Grandpa always let me do whatever I wanted in the garage, but I think grandma took a chunk out of his ass. I was relegated to fixing a broken gas meter from scratch with a sore arm and butt for the next week. That was my summer :) OMG that has to go in an ultralight!!!
LOL That's is so funny! I'm always learning something new (brake fluid and bleach) in this forum :D I once mixed ammonia and bleach by accident. That didn't work out to well.
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a.badner
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Post by a.badner »

I once mixed ammonia and bleach by accident. That didn't work out to well.
yup, clorine gas is pretty fun :)
twizzstyle
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Location: Kenmore, Wa USA

Post by twizzstyle »

Finished a new pair today, didn't take any pictures at all during the build, but I did film every step with my go pro. When I find some free time I'll edit together a cliche go pro video for public enjoyment.

I will get some pictures of the finished skis tomorrow.

They are the same as the crabby sticks I made last year, 113-85-105 I think? Something like that, 170cm length.

They are bamboo cores, with triax fg top and bottom, and a 3" wide strip of uni cf top and bottom.

For the top sheets I used 1/40" bamboo veneer, followed by some clear top sheet from SBM. No graphics of any kind, just the veneer. They look great! No sidewalls this time, just bare bamboo.

The crabbies I made last year had no camber, so I wanted some. I shimmed my mold in the middle to add some camber, and then put the heat blanket on the bottom (normally I heat from the top). Oh boy. I wanted camber, and I got it! When sitting on a flat surface unloaded there is almost an inch under the center of the skis. Oops! They're also super stiff, I think they'll be awesome to ski on.

Only major boo boo is I rushed drilling the holes for the inserts, and they a little off... And then when drilling the inserts clean, I totally f'd up the threads in one of them. Oh well so it goes, 3 out of 4 mounting bolts is ok, right?

Pics tomorrow.
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Brazen
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Post by Brazen »

hahaha o man, hahahaha. That camber will break down 3-4 mm first day. I bet you'll be left with what you wanted. I have to see 'em!!! Just tap the bad one and use a larger screw, or different thread pattern, right?
"86% of the time it works 100% of the time".
twizzstyle
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Post by twizzstyle »

Ok here are some pictures. I forgot to say that I put black pigment in the rest so that my fiberglass layers would be black. This was just to look nice on the sidewalls, I think it turned out ok. I hand sanded the sidewalls just a little to smooth them a little more, and put a very light coat of polyurethane just to make the black fiberglass layers pop a little more. Looks great, this sidewall picture doesn't do it justice.

Image

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twizzstyle
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Post by twizzstyle »

One interesting thing of note, is that even with the veneer I still got fiberglass print-through in the topsheet. The veneer is only 1/40" thick, so it's like paper.
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Brazen
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Post by Brazen »

Those are so pretty! Very nice work! Can you helicoil the insert?
"86% of the time it works 100% of the time".
twizzstyle
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Post by twizzstyle »

Thanks Brett!

Full disclosure... not only did I strip one insert... I realized they are horribly off center... wtf. I'd guess 3mm off center? Enough that it'll be noticeable when I put bindings on.

It's funny I feel like I'm getting so comfortable making skis, but then I get complacent and rush through some really important steps and get problems like this. Lessons-learned that I'll probably forget and repeat.

The issue here was that I rushed drilling the insert holes, and then I just eyeballed the locator pins for the core (I superglue small dowels onto the base to locate the core). Should have measured and done it right.

You want more full disclosure? The bases are stupid convex. I think I can do a little more grinding and get them closer to flat, but I'll never get them completely flat - the outer 1/2" curves up along the entire length. I had this same issue on the last piggy sticks I made, so I'm not sure what my issue is. Maybe on the next skis I won't rabbit the core/sidewalls for the edge tines and try to counteract one issue (convex bases) with another (rabbiting the core to prevent concave bases), maybe they'll cancel each other out! :)
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MontuckyMadman
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Post by MontuckyMadman »

cool. see the triax through the veneer, odd. that's the only time I don't see telegraphing is with veneer. convex, weird. Too much rabbit? too hot? over 180F from the bottom only.
you have like the opposite results I have.
Did you pull the ski out hot or cool it under pressure?
Most of my small problems like this went away when DBS told me to pull the composite hot and cool it on a rack or even surface.
sammer wrote: I'm still a tang on top guy.
twizzstyle
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Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

Yeah 180 deg from the bottom only. I think I'll be buying a second blanket soon just for more even heating.

I've been letting them cool under pressure in the press before pulling them. Maybe I'll pull the next pair out hot, thanks for the tip.
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MontuckyMadman
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Post by MontuckyMadman »

go 170 ish and cook a tad longer to make sure. the base warping was always more pronounced over or at 180 and pull hot for sure.
sammer wrote: I'm still a tang on top guy.
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