First Time Designing Skis

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ovaltine123
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First Time Designing Skis

Post by ovaltine123 »

So for my senior project i'm building a pair of skis, with help from my mentor. I'm looking for a type of ski similar to a Atomic Blog/Armada JJ/Rossi S7/Line Sir Francis Bacon type of ski. I was thinking the waist should be around 110mm and should have some rocker and early taper. My mentor gave me a spreadsheet to fill out that includes all the measurements of waist width, how much rocker, how much taper, tip with etc. I think I have a fairly good idea of what i want out of the ski but I'm having trouble coming up with the measurements. I'm modeling my ski after the ones i listed above but they actually have a fairly wide range, for example, the waist of the Line Sir Francis Bacon is 108mm and the Armada JJ is 115mm (so obliviously the JJ is wider) but then the tip of the Sir Francis Bacon is 140mm while the tip of the JJ is 136mm at its widest point. I thought the skis were fairly similar, but their dimensions don't show it so that's kinda confusing.

Ski i'm trying to design: I'm looking for a quick, nimble ski (lots of tree skiing) that is also playful and not too heavy (looking to put Barons on these). I hit a lot of little side jumps and do a fair amount of cliffs. Also I would like to improve my tricks in the backcountry. I'm definitely not much of a charger. I have Line Prophet 90s right now so this will be more of my pow ski. Umm I'm not really sure what else to put here..

My mentor is going to help me a lot with the actual building of the skis but I need some help with the measurements.

So basically all i'm asking is for some help designing my skis. I can answer many questions so please ask away.

thanks for any help
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nate
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Post by nate »

I think there's two ways of going about this.

1. Copy an existing design point for point as closely as possible.
2. Make up some sort of hybrid of the skis you're looking at. Make up the dimensions. One is 108 under-foot and one is 115? Easy, yours should be 112.

The first method will give something that probably skis similarly to what you're modeling. Probably will be quite difficult to pinpoint a flex though, especially for your first build.
The second method will give something that probably skis all right. Maybe great, but maybe not.

Either way you have a chance of getting a really nice ski, and a chance of getting something of a dud. And really the chances are probably about equal. The truth is to start making really stellar skis you're going to have to make a lot of skis. There's not really any way to guarantee your first ski is great.
ggardner90
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Post by ggardner90 »

kinda in the same boat, i want to copy this ski really close, just wondering hoe you guys would translate a ski into a model to make templates from
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vinman
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Post by vinman »

I just built a similar ski with Dimms of 130/142/122/132/122.
Check my Whiteroom skis 11-12 journal out for more detail.

My biggest advise is to not go overboard on the reverse side cut. I will be revising this design to have less reverse sidecut up front to decrease the tendency to hook a bit in the tip on groomed snow. I'll be shaving down the design to something more like 125-132-112-125-118 on a 185cm ski.

If you have not gotten snowcad yet, go get it and just play with the design. The more you play with design the better. As for what dimms are right for you that depends on what you'll do with the ski. Feel free to use my numbers as a jumping off point if you want.

Read all the journals also. Check put Dr. Delams designs he does a lot of 5 dimm skis.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
powderho
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Post by powderho »

The skis you listed actually are all quite different. For example, I think the Lines are half as stiff under foot as the JJ's. The JJ's have a super short sidecut compared to the Blogs ect. You need to think about the aspects of the design that are important to you and then try to design accordingly. Most of us just speculate on what a certain design change will make and go for it. The flex profile is just as important as the overall shape of the ski and that's something that is very difficult to measure without skiing the ski. I usually start the design process by choosing the waist dimension. It will be tweaked a few millimeters or two depending on the sidecut I want. I model up the rough shape and start tweaking the dimension until I get what I think I want. (Then I pay the CNC guy to cut out a template, I make the ski, and the dimensions are around 0-2mm of my design. They are never perfect.) Don't stress the design of your first ski too much. You just need a baseline that is skiable and you can go from there.
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