Science Channel's "How it's made" features Radar Skis making skis tonight - 7PM PST check your local

[Horton]

Science Channel's "How it's made" features Radar Skis making skis tonight - 7PM PST check your local listings

 

Well this snuck up on us. I texted Uncle Eddie and he did not even know about it

[kfennell]

It was on in Canada last weekend, I did not know that it was new, it was interesting to see for sure, everyone should try and watch.

[rodltg2]

I tried to record it from iPad on uverse. Hope it worked.

[Horton]

Showing 30 minutes later than expected

[tfriess]

just watched it, a nice segment

[wilecoyote]

Not sure if this link will work in the U.S but I just found it online. http://watch.discoverychannel.ca/how-its-made/season-17/how-its-made-17-episode-1/#clip766600

 

Good luck.

[Hugh Nichols]

thanks!

[bherder]

I tried the canadian link. Even used a canadian web proxy to pretend i was in canada. Didn't work :( Anyone had any luck with the link from @wilecoyote ?

[MattP]

@bherder I tried the same process as you. I was able to watch the first segmenet of the show but the 3 following would not play.

[Horton]

It was a pretty good segment. If you listen really carefully you can hear Papa Smurf snoring in the background

[Wish]

The only thing that surprised me was the first rap of carbon that formed the bottom of the ski. The foam core was placed on top of a sheet of carbon. The carbon sheet was slightly larger then the core allowing the carbon to be rapped up all the edges of the ski and about 1-2 inches over the top. The portion of the rapped carbon that was on the top of the ski was not even/parallel with the edge of the ski looking rather jagged. In some spots it seemed to be 2" of material along the top edge and in others 1", as if it was a very ruff cut out of carbon. The top sheet of carbon was precisely cut. I would think you would want that bottom carbon sheet edge to be precise with an exact margin of material. Why wouldn't this unevan margin of carbon effect rocker flex and twisting flex?

[Horton]

That was for TV. Does mean that is how the skis are really built.

[Waternut]

@Wish I'm still trying to find something that has this video online. However, I've seen a video of Radar making a ski in the past and they make them with flanges that stick out of the side of the ski. Once it's all cured, some guy comes along and cuts the flange off all the way around the ski. This is actually how most composite structures are built. If you look close at most ski's, you'll see a tiny white line all the way around the edge of the ski. That's where they cut that flange off and then sand it smooth. So really, it doesn't matter how nasty the edges are or how much larger they are so long as there is enough good material to make it up the side of the ski with a little extra.

[MattP]

[Waternut]

That's it! Thanks @MattP.

[Chef23]

My channel guide says it was on but what I got was something on making bike shoes.

[igkya]

@chef23, same for me.

[Wish]

@jfw432. They showed all that in the Science Channel clip. It's actually before that. On the SC u see the core being machined. Then he lays the core on top of a sheet of carbon that's in a very very rough cut shape of a ski. He then raps that up the edge of the ski and over a 2" margin,or so, of the top of the ski. Like rapping a present with paper thats to short to meet in the middle by a lot. He then staples the sheet....yep staples that all along the top edge to the core. He resins the heck out of that. Again this as shown was not a precision cut piece. So as he is stapling along the edge, you can see in a random fashion, some of the top edge of the ski gets more material. He then lays a precise ski shaped (much wider and longer then the ski) cut of carbon on top. Resins that down letting its borders hang well past the edge of the ski. --THIS IS WHERE @MattP VIDEO PICKS UP--Repeats with a layered white sheet, resins, and a finish graphic sheet and resins. All of that hangs way past ski to get cut off after pressing. My question was this ragged edged looking piece of carbon the core was laid on in the first place. I taped the show so ill capture a pic and post later.

[Waternut]

Hmmm... I'm curious. Will comment when I see it.

[BraceMaker]

@wish - I wouldn't think that is such a huge deal personally.

 

When working with fabric sheets it can be hard to precision cut parts, usually you have some scrap at the edges to work the resin out into and to ensure you aren't too small.

 

I would guess that there was a step where the bottom was laid up, then transfered to a mold, the edges then could be flipped over the mold and the other layers applied and wet up, then the top mold brought into place and pressed.

 

Didn't see the episode - but is it possible that step occured?

[Horton]

People Stop! That was just TV. Anything you saw may or may not be how your Strada was made. From a 40,000 foot view - yes that is how it is done but the details of how the carbon is laid was not shown. My guess is they made more than a few TV skis that were then thrown in the trash.

[otisg]

It will be on at 5 AM Eastern tomorrow on Optimum Cablevision @ 170

[usaski1]

Horton, its called how its made... obviously that's exactly how it was made.. I mean, if it wasn't, they'd have to call the show something different.

 

BTW... here in Central Texas, its on the science channel at 4 or 4:30 am jan 1st.. I set my dvr.

[Wish]

First pic (and its the same guy which is cool) is him cutting away at that carbon sheet he set the foam core on and rapped the sheet to the top of the ski. Then he staples it.

 

Second pick you can see what I'm talking about. All that crazy black is carbon sheet that's already been resined. He's about to set the more precise cut top sheet.

 

@Horton. Totally get that this could be some mock up. But my questions is. Would this extra material affect the ski if that stuff is stronger then steal.?

,

[Steven_Haines]

Personally, I wouldn't sweat the small stuff! The ski rocks right? And also, if you get too critical of their process, they're probably gonna regret showing us how they do it. I'm inquisitive, I like to learn and try to understand. Obviously those edges are a non issue!

[Waternut]

That extra stuff won't do anything worth mentioning. The stiffness and flex comes from the core and the sides. A one inch wide section of 5oz carbon (most popular) is nothing. Even 3-4 layers of the stuff at 67" long would fold up into a circle without any problems as long as it's flat. Extra is WAY better than the alternative of the two pieces not being connected in some spots.

 

I didn't think anyone made ski's of weave though. Thought it was all unidirectional cloth... Are my eyes playing tricks on me or could Radar be playing tricks on us with their material selection for the video?

[tfriess]

The segment was using a mold for a 66

[ToddL]

Time Warner cable ch 1409 on demand, 20 minutes into the program.

[wilecoyote]

What @jfw432 said. In theory there would be a difference between skis laid with more or less overlap, but the difference would be very small. Also you'll notice that there was re-enforcement added to the front of the ski in the photo but they didn't show the worker doing it. Also, pure unidirectional is great if you have a complicated lay up schedule to get exactly the flex you're looking for, but it doesn't wrap around rails very well, and besides this is a mostly unidirectional weave any ways.

 

@Horton, are you on crack? In what conceivable world would you make $4200 worth of skis just for TV and then throw them out? Radar has nothing to hide or be ashamed of, the clip shows how they're made, and thanks to Radar for showing us!

 

What I found surprising was that they weren't using prepreg.

 

Sorry the link didn't work guys, I kinda figured it wouldn't.

 

Chris

[Waternut]

@Wilecoyote When you are able to use an autoclave or a press while your wet layup cures, there is very little if any benefit to prepreg fabrics in terms of weight and strength. Vacuum bagging helps too but not as good as the other two. The main benefit of prepreg is really just ease of use when using enough pressure.

[usaski1]

damn, I recorded the show on dvr, it said "waterskis" on the heading, and I got oil paint sticks! grrr!

[Wish]

Ignoring whether it is or is not the way they build a ski for a moment..... So what I'm getting from the thread is that the carbon sheet mess on the back of the ski core, (that's already resined down) wont effect a thing?????

[danbirch]

Here on Fios, it was a show called "Fringe" for most of the evening.

[Waternut]

@Wish That's correct. The cross sectional area increase that that little overlap adds would be minimal. Plus it's in a compression zone on the ski right next to a vertical member (the side rail). That little thin strip of carbon will immediately buckle (bend) when loaded in even the smallest compression load. The arguement could be made that the rebound of the ski would be changed when that extra strip rebounds back to it's natural position but that'd be like stretching a rubber band behind a tennis racket... It might help keep the ski together in an OTF fall though.

[wilecoyote]

 

@jfw432, I've never used prepreg myself, been doing wet layup and vacuum bagging for more than 20 years building windsurfers (personal use and friends, not professionally) but I've always wanted to use prepreg. I just looks so much easier, but I suppose material cost is much higher.

 

I'm keen to build a few skis this year, and I'm thinking about vacuum infusion. Windsurfers are a bit too big to risk a new process but skis seem much more manageable. Ever tried it?

 

 

[rq0013]

I made a carbon trick ski using vacum bagging.

[BraceMaker]

Precutting the carbon such that it would wrap the ski and butt up on the top or be even along the edge would be super tricky.

 

Vacuum bagging is different than vacuum infusion. Vacuum bagging you wet up your layers. Then bag. Then pull vacuum.

 

Vacuum infusion you have to pull the resin through your lay up while under vacuum.

 

Resins are a bit thinner. Can be trouble you dont know if your infusion fully saturated to the core until it fails.

 

 

[Waternut]

@wilecoyote I'm in a similar boat to you. I've built a custom jetski hull out of carbon with vacuum bags. Resin infusion is a really cool concept but in my opinion, that's a lot of money in startup costs. Plus, I don't think people have dreamed up enough way to mess that process up. Also, I don't know about you, but I've never been able to pull a perfect vacuum without leaks. None are ever big enough to cause a problem with a wet layup but in resin infusion, they are a big deal. I personally wouldn't be willing to try the process on something that I have $600+ in carbon fiber and resin in. If someone had the equipment and let me borrow it for something I have less than $100 in materials in, I think it'd be cool to try.

[ForrestGump]

I found it really interesting to see the machining of the cores. Does Radar machine their own or contract it out? Just curious.

[ampacdan]

they do mention that 'depending on the model and it's performance specification, they wrap the core in up to 7 layers controlling flex with additional patches of fibre' - because of this - I would agree with @jfw432 that the uneven overlap is insignificant.

[wilecoyote]

@jfw432 I've never gotten a leakless bagging either. But I've been bagging onto a table and I think if I went the poly sleeve method other shapers use I could. Especially something as small as a slalom ski As for start up costs on the infusion process, I don't think you need to go the full on route for a slalom ski. You could certainly cobble something together good enough to give it a go.

 

@Brace maker, I'm guessing you've done infusion?

[BraceMaker]

Infusion is all I do at work, but then I remove the plug, so I can verify that the wet out of the fibers.

 

I use PVA bags inside and outside with vacuum, then infuse. I've been cobbling together a 3 axis router to cut some foam cores and try my hand at making some skis. I'm at the point where I need to determine how large I want to make the long axis - part of me wants to build my router to cut ~70" by 2', but it would be far easiler to make it shorter, and then move my core half way through.

 

For a slalom or ski the big problem with infusion, is that whatever your core shape is, the fibers will produce a fatter rounder edge, as the fibers will curve around it and make it a "muddy" shape.

 

With out some form of negative mold it is hard to correct for this. Hence my router project, I figure I carve a negative of the running surface. And carve a core, then lay up and infuse the ski, push it down into the negative and press it while under vacuum to fix the running surface.

 

This will never be financially beneficial, or improve my skiing. But could be fun.