The Rumpelstiltskis

[Grizzly Adams]

Howdy all,

Just like every second post in this forum it seems, this is my first build and I'm pretty damn stoked.

Long before I started the project, I've thought about what my ideal ski would look like and, though many ideas came to mind, I settled upon a powder board that would be versatile enough to use all over the mountain that also had a pretty tight turning radius (~20m). They would need a catchy name (The Rumpelstiltskis), and in addition they would need to be long enough to drop huge cliffs and stay stable while I mach past gapers on the flats, lol ;-). More importantly, they are going to have an absolutely glorious topsheet, but I can't let that cat out of the bag until later.

The ultimate dimensions are:
Tip - 130mm
Waist - 95mm
Tail - 120mm
Length - 190cm
Camber - 25mm

To begin with, I needed to collect all the tools we had from our storage unit, which happened to be piled to the 15 foot wall ceiling with poorly labeled boxes, awesome. Luckily my brother was there to help me and we grabbed what we needed fairly expediently.

Next, I had to set up my verkshoppe, and by workshop, I mean my parents garage. I started by moving a bunch of extraneous stuff to storage and covering the remainder with painters plastic. Next, I decided to expand my work bench a bit to accommodate long materials.

This gave me some room to play around with.

My cousin Jeff and his dad (a fire marshall) were kind enough to donate some 5" fire hose for the bladder, all I had to do was devise a system of fittings (and silly amounts of marine sealant) to allow for inflation.

Poking around the forum really helped me out there. For the mold, I picked up a bunch of lumber and I though I haven't started construction, its going to be adjustable to allow for skis from 170cm (probably never going to happen) to 244cm (now we're talkin). Incidentally, I also had the good fortune of meeting a guy who works for a local company that fabricates specialty metal work for the oil and gas industry among others. He agreed to help me with my press frame and can pull together some cheap steel as well. I drew up a design and hopefully I'll be able to start welding soon. Its going to be made almost entirely of 3x3 steel tubing.


I elected to create an adjustable core profiler so you can change the thickness based on how you want the ski to flex as well as the length. Righteous. Its kinda a hybrid of some conceptual sketches I've seen of adjustable camber molds and some of my own ideas. It still uses side rails, but not of the same type as most pictures I've seen on the forum. It basically uses a system of screws and this sweet .75x1.5 MDF moulding I found at the lumber store.



This gave me a chance to do some routing on my first laminated core (which happens to be a combo of red oak and poplar). I wore safety glassez, but the router created outrageous amounts of saw dust (and by saw dust, I mean router dust) and I soon found my eyes rather irritated.

I thought to myself, its too bad I don't have safety goggles... when a brilliant idea occurred to me.


I've been able to get my cores (poplar and red oak) laminated and planed down to the correct thickness to provide the desired stiffness (wicked stiff).

Also, if you're a huge nerd like myself, you'll notice that the vibrations from my router are also creating sinusoidal waves out of the sawdust thats left behind. Super cool. After flexing the cores, they feel really nice and smooth. Incidentally, the cores alone are already thicker than my finished Dynastar XXLs. They are going to be absurdly stiff, which gets me rather excited.

Then, all of a sudden, a deer walked by the garage!! His tree camouflage was no match for my camera.



Since I embarked on this epic ski making extravaganza, I've consumed a lot of raw materials to keep the ski building process going and some of the numbers are staggering. Check out the list below

Astonishing Figures
* 22 gallons of sawdust vacuumed (thats the only one thats really all that astonishing I'd say, but keep reading any ways)
* 250 wood screws
* 4 pieces of .7 pencil lead
* 125 tissues (allergies)
* 1 case of coors light (pounders)
* 15 cornbread pancakes (PM me for the secret recipe)
* 17 splinters
* 1 bent drill bit (sorry dad, but its that tiny one we never use anyways)
* 69,120 pounds of force predicted in my press. (F=P*A) (yarrr)

Also, the majority of my materials arrived in the mail yesterday from the skibuilders.com store, and the quality of them looks really good. I've already got my Ptex cut so it has some time to relax before I tack edges onto it. The only outstanding item I need to purchase is epoxy and I hope to get that ironed out soon.

As I mentioned earlier, I plan to make the mold for the skis adjustable and all that will be required to change the length will be a simple slide. It will work something like this, except instead of electric, it will operate manually.

You wont get any more updates over the next few days as I'm headed south to pick up my brother from the airport. We plan to spend a few days in the Medicine Bow range camping and shredding some gnarly couloirs. I imagine it will look a bit like this photo that was taken about a week ago near the tetons.

(insert shit eating grin here)

Perhaps I'll post a TR when we get back.

-grizz

[Grizzly Adams]

So I've been working and traveling over the past few weeks and finally got a pair pressed and cleaned up. I've been sending out long detailed emails to friends and family (let me know if you'd like to be on the list), but since you likely already know all about the process, I'll spare you the details and show you the pictures...

Building the Press and Molds, Preparing Materials, Laying Up and Pressing

The Finished Rumpelstiltskis

Some comments about the finished product

The wrap-around edges on tips and tails were a booger at the time, but came out really nice and will make them much more durable

The addition of beveled sidewalls make them look much more professional

The glossy topsheet came out really nicely, though the packaging tape was a bit tricky to remove (it did, however feel like xmas morning)

Given the darkness with which the graphics came out, the stickers look dope and save the skis' appearance to some extent

If you have ever flexed DH race boards, you will find that these guys are actually a smidgen stiffer... WOOF

I'm glad I put the work in to do it right the first time

I'm hungry for some corn cakes


Final Specifications
Tip135 - Waist100 - Tail120mm
5mm camber
Length 190cm
2.7kg or 6lb (about the same as the xxls i believe)
Twin Tips
Poplar Sidewalls

All in all, I'm really stoked about the way the came out, the few problems that occured were as follows:

The graphics came out pretty dark and my rice paper didnt go entirely translucent. Also, a fold in the fabric is visible beneath the topsheet. They still look nice, but I would've preferred brighter graphics. The die cut vinyl stickers my cousin made me help this out a fair amount.

Some epoxy leaked onto the base, but that will come off with a good stone grinding/ tuning

A few slight dimples are visible in the topsheet... likely from some sort of dust/sediment trapped under the flashing I used as a top pressing layer.



Success on the first try! Righteous!!

[doughboyshredder]

Nice skis!

How much did you shit your pants when that top mold blew up? What pressure were you at when it blew? How did you fix the problem? Did you see any deflection in your press frame?

Good work!

[Grizzly Adams]

Thanks a bundle sir.

I must admit that I shit my pants pretty damn hard. Luckily I was tucked behind my 300 lb work bench with safety glasses on while I was inflating the bladder. It went at a little better than 50psi, but in retrospect, the design I pulled out of nowhere was rather poor and relied on the strength of particle board (does such a thing exist? I think not). I fixed the problem (which was a silly mistake in the first place) by switching the particle board out for MDF and using only horizontal 2x4 ribs which in effect distribute all of the force across the steel instead of expecting the sheet of MDF to do any work.
This picture illustrates the new design

Granted I've only been up to 55psi at the new design (I press at a humble 42psi) but I havent noticed even a micron of deflection (I've measured multiple times with a .59cent plastic ruler from office depot). All kidding aside, I'm pretty damn proud of my press design because of its strength and the fact that you can break it down into sizes that are easily movable without even touching a wrench.

[Nick's Sticks]

I like the plaid and the skis really clean. What are your core thicknesses? The tips look pretty bomber.

[Yuki_otoko]

Impressive looking skis.

The centre support, does it slide down to one end to allow entry from the side? Or is it fixed and you slide it all in from one end?

[Grizzly Adams]

'preciate it

the cores are about 3.5mm tip and tail and 15mm underfoot. The profile is designed to be roughly parabolic without a flat spot under the binding. It is pretty clear from the sixth picture down...

http://dwyer.haney.googlepages.com/therumpelstiltskis

...that the tip and tip spacer interface is pretty poorly matched. I think I did an adequate job of filling that gap with epoxy and glass, however, and I'm not too concerned about failure/delam there.

Also, if you look very carefully at the skis (and perhaps the first picture on the above page) you will see that the added thickness (actually its probably just the stiffness of not wanting to be bent) has caused a slight raise in the topsheet where you can clearly make out the interface between the core tip and tip spacer area.

As I'm sure you can deduce by the core thicknesses and the fact that there is some red oak in there, these things are absurdly stiff and I presume they will only be happy at mach schnell.

[Grizzly Adams]

yuki:

I didnt even think of sliding my center support down to one end for side entry and as a result, I made my molds just as long as the press (8ft). It would certainly be feasible with shorter molds, however, and would doubtlessly take some of the hassle out of loading the couple hundred pounds of molds in there. Thanks for the idea!

[hugocacola]

your skis looks great. but i have one thing to say you. the gap betwen sidewall and tip spacer must be lower...

keep good job...

best regards

[Grizzly Adams]

thanks man, I'm definately going to be cutting that gap down (to zero) on the next pair.

[RoboGeek]

you get my vote for coolest ski name!! lol

[knightsofnii]

just to clarify I think what he means by the gap between core and tipfill is the thickness difference. try to get the core profiled down to match the thickness of the tip fill. if you have trouble with that, try thicker tip filler.
same thing happened with a board I built at home and there were huge voids where resin just leaked out of the board so there were bubbles.

you can always just sand down the last cm or so of your core by hand to match it to the filler, just try to get it to taper down so everything bonds well.

[Grizzly Adams]

just to clarify I think what he means by the gap between core and tipfill is the thickness difference. try to get the core profiled down to match the thickness of the tip fill. if you have trouble with that, try thicker tip filler.
same thing happened with a board I built at home and there were huge voids where resin just leaked out of the board so there were bubbles.

you can always just sand down the last cm or so of your core by hand to match it to the filler, just try to get it to taper down so everything bonds well.

Thanks for the clarification kind sir. With it being my first pair of skis, i got pretty damn concerned about how thin that tip was gonna be and how easily it would break (considering the glass and epoxy reinforced version, its not even close to breaking even if you hit it with a freakin maul) The pair I'm building now are powder boards and I've got em profiled down to a perfect 2mm so there shouldnt be any difference in thickness. And by perfect, I mean a lot closer than the 4mm of the 'stilts, but considering the most accurate measuring tool I have is a 59cent plastic ruler, its probably not all that close.

NIII