FX-1 WDK F1 Pro Build

[LimitedSlip7]

I got the itch to build a new ski this winter after my riding buddy bought a carbon REV hull a month ago. I hate to be stuck riding a plain ole RN next year, despite having just spent countless hours rebuilding it from the hull up earlier this spring, when he is zooming around on a nice AM hull. Problem is I'm broke from having too many hobbies so when I saw an old carbon WDK F1 Pro hull pop for what seemed like a reasonable price I jumped on it. The hull turned out to be in worse shape than I had hoped, but I've got it in my garage now so I might as well start hacking. The hull appears to be an early prototype and not quite like the current F1 Pros. It feels pretty damn heavy right now with the wet foam but I'm really hoping it will be close to the ~60lbs of the current carbon F1s after I clean it out.

It came with Tom21 tubbies and widetray so of course I'm going to be installing those. Not quite sure if I am going to reuse the footholds that came with it. I am also planning on shortening the hull 2-4"; any recommendations? The side rails have been hacked up pretty bad and there is hardly any lip so I'm thinking about getting some carbon strips and riviting/blending them into the current rails.

Pics: http://s104.photobucket.com/albums/m187/limitedslip7/WDK F1 Pro/

 

[swapmeet]

Ive ridden a FX that's minus 3 with flush cut pate and it's nose high big time. I have one that's minus 2 and I had to stick a extended SJ plate on it to ride like I wanted it to. The plate stuck WAAAY from the end of the hull because of how much it was cut.

I think if you shorten it, you should widen the bond line, at least in back to keep the nose down some.

Just my two cents, I'm sure others will differ.

 

[LimitedSlip7]

Well, the F1 Pro has the pump set back 2" from the FX1 location and I've heard that makes a pretty big difference. Were the ones you rode set back?

I am thinking about widening the bond rail though since I have to repair it anyways. Think 1/4" per side would be enough or should I go more, like 1/2"?

 

[LimitedSlip7]

Well so far I've purchased:

6mm 840 Xscream stroker
EPIC ignition
62T ebox, stator, flywheel, start/stop switch
R&D intake grate
Sato trim system
44mm Blackjack carbs
V-force 2 reeds
R&D intake manifold
Factory Pipe waterbox
Cold Fusion billet coupler

I also just ordered about $200 in carbon cloth and epoxy resin. I also decided to sell the widetray and go with Tom21's new adjustable footholds when he releases them (hopefully soon!)


I cut the tray out and cleaned out all the wet foam. Original owner had like 20 one way valves in the damn thing so the firewall looks like swiss cheese now...

Chopped 2.5" off of the rear.

Finished pulling all of the tubes out of the tray.

Cut the 90 degree portion of the bond rails off leaving ~1" sticking straight out to build the new rails on. Also cut out the front exhaust.

All the mounts were glued in place with RTV and were loose/corroded. Pulled them all out and will have new mounts machined. I'm also debating wether to rocker the front a bit or not...

 

['kotajoe]

Nice build, im building up my first fx1 hull right now too. Have you been able to weigh it since you de-foamed it?

 

[LimitedSlip7]

It was ~70lbs after defoaming but before hacking all the out and off. I can easily pick it up and move it around now. Hoping to be under 80lbs with the tray/footholds/rails and all hull work completed.

 

['kotajoe]

Ah nice, I have done a -3", installing the Tom21 144 tunnel, and rockered the nose. Also plan on doing adjustable footholds as well. Hopefully ill still be under 100lbs when its all said and done.

 

[redwood]

Good looking ski, It's coming along nice. I've got a f1pro that I'm working on right now. I'll be going 1.5" shorter on my fixed steer fx this winter. Good luck with the ski...

 

[swapmeet]

Sorry I didn't see your question about the setback pump. Mine was setback 3" via adding a second wear ring.

Man I saw where you chopped the back off that carbon hull and I almost threw up in my mouth a little. High five to you for having the balls to chop it up. That firewall is crazy.
Glad to hear that you're widening the rails. Makes me pretty excited about your build.

Concerning Rocker, wouldn't the rigidity of CF make that tough without breaking the strands and/or compromising the integrity? Seems like if you used any of the methods we've seen on the X you might as well cut the bottom of the front off and start a new layup because of the CF. I'm sure you have a plan, but i'm just thinking out loud :thinking: (yeah I said that) about how you could do that and not take away from the hull's existing attributes.

Keep it up!

 

[Idok]

Well, the F1 Pro has the pump set back 2" from the FX1 location and I've heard that makes a pretty big difference. Were the ones you rode set back?

I am thinking about widening the bond rail though since I have to repair it anyways. Think 1/4" per side would be enough or should I go more, like 1/2"?

this is the defining characteristic of this ski! it makes HUGE difference in the overall balance

 

[LimitedSlip7]

I'm not really sure if I want to rocker the front end or not. I might just curve the bond rail up a bit in the front for a "pseudo-rocker" so I don't have to cut the out of the hull. I'm trying not to go too extreme with anything so that the ski still handles like an FX1 (but better!) instead of becoming something completely different. The rails will flare out a bit around the tubbies, like the BOB gen 3, and then drop down further in the back like the Freaks.

 

[swapmeet]

 

[LimitedSlip7]

A bit further along on the build.


Half the motor mount inserts were junk so I made my own out of 304SS:

Used Six10 to epoxy them in place then covered with a couple layers of 5.5oz

Taper bored and radiused my Sato nozzle:

Reinforced the pump/tunnel with a layer of 5.5oz, built the back ends with two layers of 20oz and one layer of 5.5oz:

 

[LimitedSlip7]

Machined all new mounts from 6061, welded up an exhaust tube, and epoxied everything in with six10:

Started building up the tray with expanded polystyrene foam boards:

Shaping the foam:

Final Shape:

 

[LimitedSlip7]

Laid down two layers of 20oz:

Then a layer of 5.5oz:

Preview of the adjustable foothold rails:

 

[ProSouth]

your carbon work looks minty, great job. i looked at this hull a lot when it was for sale. i just couldnt do it.

 

[LimitedSlip7]

Yea, it was rough. I saw a few crappy cell phone pics of the good areas before I bought it, so I assumed it was in better condition than it was.

I tried to use as little epoxy as possible by sandwiching the carbon between wax paper, lightly wetting it out, then heated it up and used a rubber roller to squeeze out any excess epoxy. I then peeled off one side of the wax paper and applied the carbon before peeling off the other side. Found it very easy to work with using this method; no problems at all with fraying and easy to handle.

Think two layers of 20oz and one layer of 5.5oz will be enough for the tray?

 

[hornedogg79]

wow! that looks great dude. I'm in the process of doing something very similar to my tray.

 

[LimitedSlip7]

Thanks, it's 16.5" wide now. Probably could have squeezed another inch out of it if I really wanted to.

 

[KTM434]

Nice build so far. I rode Idoks and have been very tempted by these hulls ever since then. I only rode it in flatwater near our launch but it was a real cool ski for sure and I'll consider one whenever I see them pop up for sale now. Definitely a learning curve involved though and it's not for everyone. How much have you spent so far in carbon fiber?