Ski Builders Forum

we have been playing around changing the camber on a testbed pair of skis
going from zero to 1/4" then 1/2" then 5/8" ,
finding out a little change in camber makes a hugh difference as to how they ski

do any major ski producers cut out the cores with shape/camber

would it make the ski more lively?

do you think the non cambered core serves to enhance dampening or hinder?

I think there is a few high end custom snowboard guys that do it but its a real pain.

The real reason for this may have been the lack of high quality epoxies for the small qty builder. Or maybe the lack of heavyweight multi-axis composites. Causing the camber to fall over time perhaps.

I don't think you get any benefit from this type of profiling.

I would think it would make it tricky in layup perhaps as well.

I think the home builder experiences to much liveliness in a ski so more pop might not be needed.

coiler profiles the camber and core shape in to a block of wood using a router bridge.

His alpine boards are some of the best. The concept, I believe is that this reduces or eliminates full length wood grains which reduces harmonic transmission. I.E. it's supposedly damper.

Seems like a hell of a lot of extra work for no real benefit.

If I remember correctly, Volkl used to cut the camber into their cores. I don't know if they are still doing it or not. Their skis always had a lot of energy in them. The claim was that the fibers were in a neutral position
when in the cambered position so when you flexed the ski, it reacted immediately. I am not sure it this was marketing or engineering.

So has anyone tried steaming the core and then drying it in a fixture to
put the camber (and tip curve) into it. It would be like the guys that steam
their stair rails. We used to steam the tips of the snowboards at a company that we built tooling for. They would dry the tip and tails of the core in a fixture after steaming it. The cores would come out shaped like the mold. It seemed to work great.

It's amazing how many folks here have a lot of similar ideas. Just goes to show you that there's a lot of thinking going on... that's a good thing!

I've also wondered if steam bending the core would make a more lively ski. It would seem that the ski would keep its' camber after pressing. I press at room temp so I do lose a little bit of camber. I imagine the ski would keep its' camber longer over the life of the ski too.

As for cutting the camber vs steam bending the camber.... I wonder if one way makes the ski damper or livelier to the point where you could actually feel the difference. I would think the steam bent ski would be livelier but by how much and is either method worth it? Or does it just make for good marketing? Seems like a good way to add pop w/o adding exotic materials?

The layup would be a little trickier on a pre-cambered ski unless, , you did the layup on a form that had the same contour as the cambered ski... ie the forms used for pressing.

Think I'll add this to my "experiment to-do" list, if I ever get around to it. I do like the steam bending idea... I might just build a steam box and give it a try.

I would invest in a good moisture meter if you are going to do this. Make sure that your cores are dry before using them to build skis.

Cadman wrote:I would invest in a good moisture meter if you are going to do this. Make sure that your cores are dry before using them to build skis.

Good point! The last thing you want is the ski to start distorting over time.

What would be the difference between steam bending and heat pressing? Steam bending would just stretch the wood fibers before the heat press, as opposed to during the heated-press operation.

I guess what I'm trying to say is that the core structure would be in the same orientation by doing it via pre-bent steam bending and a heated-press operation? Whereas by cutting the camber into the core you are starting with a different grain orientation/pattern.


Just hypothesizing.

Jekul wrote:What would be the difference between steam bending and heat pressing? Steam bending would just stretch the wood fibers before the heat press, as opposed to during the heated-press operation.

Simply heating and bending a piece of wood won't create a permanent bend unless the wood is already very humid (green wood) - Wet wood is not the sort of wood you want to be using for a core. If you heat and bend a piece of dry wood, you may get some semi-permanent bending, but it will be at the expense of degrading the material properties of the wood - basically you'e "burning" the bend in.

Steam bending is permanent, results in zero stress in the material, with no loss of physical strength.

The only downside to steam bending is the need for drying time, I'd suggest a minimum of 4 or 5 days, maybe up to a couple of weeks depending on where and how you're doing the drying.

tufty - yes, I agree the wood needs to be dry. For the home builder or a small custom shop steam bending lengthens the ski building process which may not be such a big deal.... you can make a handful of pre-bent boards over the summer and let dry till you're ready to build skis/boards sometime later. But I can see it becoming a hassle for any company, large or small, where time is money, and then have to store the boards in a form somewhere to dry until they reach the proper moisture content.

Hhhmmmm.... I'm starting to see this as a hassle Only because my work shop is a multi use shop with other wood working projects in progress.

I found simple plans for a steam box if anyone is interested.

http://www.instructables.com/id/How-to- ... ding-wood/

http://www.lulu.com/items/volume_1/5500 ... /55471.pdf

skidesmond wrote:But I can see it becoming a hassle for any company, large or small, where time is money, and then have to store the boards in a form somewhere to dry until they reach the proper moisture content.

Once you've let what you've steamed cool down, it goes back to being rigid (if a little moist). You'd probably want to rack your cores after steaming and cooling to stop them warping too badly when drying (after all, if you don't pre-form them, you're gonna be bending the hell out of them when you press, so what's the big deal if you pre-form and then have to press a couple of millimetres back and forth here and there).

The factory I got toured around by someone I know had a smallish trolley with about 30 or 40 machined and formed snowboard cores racked on it, and another one for pairs of ski cores. The racking system was dead simple - 3 horizontal bars per core / pair - one for the "top" of the camber and one each for the contact points. Didn't appear to differ for different cores, so they obviously didn't consider it to be *that* important. I didn't ask how they formed the cores, because I didn't think about it at the time.

Oh, ok I was thinking it had to say in the form for a day or longer, that's not so bad then. Thanks.

The company that I spoke about did hundreds of boards a month and had no Hassles drying their cores. They used a formed fixture and used a heat blanket. The other company made a heat box and put their cores in it to dry
on a small fixture. They were pretty sucessfull at it and they used pre preg to boot which doesn't like moisture at all.