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Sweet Home Alabama Skiing
Senior Judge, Senior Driver, Tech Controller
My new and improved SlotFin. Same shape, minor upgrades! $149.99 plus $6.99 SH in the USA. Outside the USA, shipping costs will vary.
PS: GREAT VIDEO !!!!!!!
Back in 2003 I designed about 30 fins, made about 15 of them. Will and Paul of D-3 tested some of them. My fav was the top loader, you didn't want to be hard in the turn, but the more you loaded going to behind the boat the tip of the ski could pull to 90 degrees to the boat. That's what a crazy auto designer does, that loves to ski. P.S. loved the Carbon Fins.
A Good One Ball Gives You Six
The basic shape I get. It's essentially a delta wing which doesn't reach a point of stall as angle of attack increases, it just continues to loose lift. This makes sense as the fin never completely stops working, it just slides more the more it's pushed. The problem is, it's not a particularly efficient shape, and when you punch a bunch of holes in it, you make it worse. I may do this experiment my self, but I would wager that if you were to draw a line connecting the edges of all the holes, and then cut the fin along that line, it would perform nearly the same.
If you think about a fin under static pressure - you can define it with center of pressure and amount of drag. The problem is with that thinking is that the angles and pressures are never static. A slalom turn is a long dynamic slide where the angles are constantly changing. Even Adrian Newey will admit there is alchemy in the science.
As a side note - I believe that the standard fin shape is the way it is because it is easy to make by hand - not because it is best. Back when I made CarbonFins I made hundreds of fins by hand. The standard shapes are easy to make and arguably organic.
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Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
The fin is asked to do a lot of things, as @Horton points out. We want the ski to be fast behind the boat, and hold direction off the 2nd wake, while keeping the tip high enough to keep the ski going out, but low enough to still be efficient. Then we want the ski to slow down coming into the turn, while at the same time we want the ski to start to rotate, then as the speed drops dramatically we need the tip height to be stable as the tail slides through and the ski starts to point across course. Then as the line comes tight we need the ski to be stable without getting behind us, and when we start to pull we want there to be the most acceleration from the ski with the least amount of load/drag so we can start the process over again.
It's a lot to ask. It's also why setting up a fin can be so challenging, and despite popular opinion, the fin effects all of this, not just the preturn and turn. So yes, holes add drag, but at some points we want drag, and depending on the angle of attack of the fin and the location of the holes, they do different things, and it's more than just pressure relief.
As Horton said there is some alchemy there. This new fin is the result of years or testing. We may have an idea that makes sense on paper, but then we need to build lots and lots of different prototypes, testing and tweaking to try and learn what's really going on, and what works the best. This whole process has been really fun.
I can attest that there were quite a few ideas that were abandoned, but the bottom line is this new fin WORKS.
If you do not believe me as @Rico if I was excited after my second ride.
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Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
Anyone who invested time trying to decipher fin design will tell you there is some 'black magic' going on. The surface-area and pressure-relief arguments that @Horton eludes to, do have merit and are valid under certain circumstances. However, I find that explanation falls apart and does not hold true under ALL conditions/situations the fin is exposed to within the slalom course.
The new Denali fin takes advantage of some of those 'black-magic' hydrodynamics and brings a new level of performance and tune-ability to the water. We are just scratching the surface of what is possible, and I'm more excited then ever to be on the water digging deeper into the rabbit hole.
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Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
Thanks for your answer @AdamCord
@BraceMaker good guess but no
@chris55 the science fin will help any ski, and we are offering them for free with the purchase of a Denali ski if you want to try it
Support BallOfSpray by supporting the companies that support BallOfSpray
Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
Sweet Home Alabama Skiing
Senior Judge, Senior Driver, Tech Controller
last Saturday....but my lips (and fingers) are sealed
Support BallOfSpray by supporting the companies that support BallOfSpray
Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
Support BallOfSpray by supporting the companies that support BallOfSpray
Barts ★ Connelly ★ DBSkis ★ Goode ★ Hobe Lake ★ HO Syndicate
MasterCraft ★ Masterline ★ Performance Ski and Surf ★ Reflex ★ Radar ★ Stokes
Ok fine. I admit it. It's awesome.