Internal Fins / Finless Control System.

General Discussion
61

Very interested in seeing one of these ridden.  Will there be any video or photos posted soon? 

62

Finished the side-fin plugs overnight.

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/twinnyvents2010004.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/twinnyvents2010005.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/twinnyvents2010003.jpg[/IMG]

I might go with riding it as a twinny first and then put in the centre tail vent.

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/twinnyvents2010006.jpg[/IMG]

 Ive had suggestions about using a router to do the vents instead of fabricating them, and also about injection molding.

63

 Thanks Huie, apart from Herb Spitzer I didnt know of anyone who had done any intentional or accidental work with water- style induction ports..

 But I guessed there musta been a few who'd given it a go at some stage.

64

Tblank, the turning mechanics are pretty much the same except for the initial engaging which is 'softer' in feel. It still... tilt the deck and lay a rail in or you can do the longboard pivot. 

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/fin004.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/fin003.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/fin001.jpg[/IMG]

Actually Ive left a 10 foot longboard with internal fins in Queensland that I'll bring down in a week and post some pics of it.

Heres an edit to the older vent design, the newer one is on the right..

 The deck opening is moved further back, compressed and wider at the back. Same area but it works and looks better.

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/fin005.jpg[/IMG]

65

Just curious surffoils, how do the internal fins work on more powerful waves?

 

I’m thinking of the scenario of when you’re on a powerful wave and there is a lot of lift and speed being generated by the wave itself (e.g. super bowly wave over head height), making it a little harder to bury a rail quite as much. Has it even effected the internal fins ability to hold in?

66

Hey Cap’n, search for the finless video of Derek Hynd at J Bay. If you haven’t seen it yet, it will open your eyes. It did mine.

67

These first few boards all rode well enough, its a real difference to ride not for pleasure but to quantify and qualify a design component, takes a bit of the fun out of it !!

A few things came out of these designs.

The width of the opening is just as important as the angle of the inside wall. (A-B)

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/widthdifference-1.jpg[/IMG]

So the opening under the board needs to be bigger/wider at the front and the opening on the deck needs to be bigger at the back than the front.

 Also, the top opening can be a lot smaller than we first thought.

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes003aa.jpg[/IMG]

So much of the water exhausting turns into froth and it seems prudent to keep any opening on the deck as small as possible.

 

Cptn, I feel that the vents are self controlling in that they can only take in so much water at any time so a certain size vents works at a certain level up to a certain speed.They build up in control as the speed increases but then the control plateaus at a level.

For greater grab ,youd have to put in bigger vents. The boards dont have to tilt onto the rail to work, they give good control just in trim. ( I think thats what you are asking.)

68

Surfoils, would you say the vent allows for drawn out turns better than snap turns? Do you initiate turns in a sliding motion a la snowboards, or is the rail involved? Or, does the board have to be pivoted like a long board? Keep up the good work. This is very interesting.

ps. The “foam collar” process can be expedited with routers and beveled base plates with a top bearing bits or rub collars, perhaps.

69

Great suggestions about installing ! We're working to get a shape that makes it easy to install without all that digging but the foam collar is a good idea,thanks.

I found the early board...

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes006.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes009.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes007.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes008.jpg[/IMG]

After that we changed the active side from an acute angle to obtuse like this....

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes010a.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes004a.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes003a.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/prototypes002a.jpg[/IMG]

 Volume of water is good as well as the effect.

70

Those are the best pictures I’ve seen so far. That’s great. How did that first board ride?

71

If you know how to use the rails (edges) snowboard turns do not have to have any sideways slide at all

http://www.youtube.com/watch?v=x5GlfDzs89s&feature=related

When I lived in CO for 5 years that was my surf substitue, that and floating through powder!

72

Cool work!  Im sort of bumping, reading along and wanted to ask if airflow effects how poorly water jets through the vent, and if that has any effects on the boards traction/grabbing.  I would guess that any air that became trapped may create momentary loss of control for the rider.  Presumidly....or does the higher pressure of the water from under the board wash out or spray out any bubbles that come up from the surf?  Mainly thinking that problem areas would be white wash sections of the wave or maneuvers that require the board to leave the surface of the water.

Cheers,

Nick

73

Ok Doctor, Now that looks fun!

74

This is such an interesting subject. Bumped to subscribe. Would love to try out a board with the internal fin concept.

75

The biggest difference between that and linking a bunch of bottom/top turns on a juicy point wave is that if/when you fall, you just get back up and keep going  On groomed runs like that, no beat down, no paddle back out etc.  Sort of icy tow in really if you think about the lifts as the jet ski.  First time I got it 1/2 way dialed, the next day my quads were so sore I could barely walk!

76

So what angle is the water flowing through the deck? I remember earlier in this thread we were talking about the angle between the port and vent but I don’t think you ever said. 

77

Im not clear what angle you mean ?

 These are the blocks for the molds for the longboard. 45mm / 1.75in thick EPS

78

brett

     i think you allready know this but for what its worth?

 

 

 if you have a look at the board in this link Hewston Surfboard
and the hayden shows it better we were installing a fibreglass box then setting the fin in it
so when you have a bunch of young shapers it dont take long for them to try anytrhing and everything so they soon put the box right through the board which lead to fins being able to wedge in from deck so they often lost a fin but kept surfing  (venturie) haaaa''
 
**cheers huie**
79

Thanks for that tblank, found it.

Thats great Monkstar, looking forward to seeing yours.

Heres a few tips, they might help.   You can see in the last pics that the mold shown and the vent are different versions. They both have the same bottom shape but the  newer mold has the deck port moved further back. The water races out the back of the deck port at such an angle I dont think it needs the deck port to be forward. You can see that effect in the pics I posted pages ago.

 The shape of the deck port changes shape when you install anyway. Im not doing any toe in, I find it makes the board react faster without it. The shortboard has the active edge 16 cm out from the stringer.

 The white pigment makes it blend better to a white board.

 Use lots of mold seperator, I use solid car wax but the more the better, and a goodly layer for every vent off the same plug. Consider your design for undercuts that will make getting the vent off the plug difficult.

 I dry fitted the vent in and then taped the bottom shut smooth and then ran Qcell/resin in from the top, peel of the tape and its almost a perfect finish on the bottom. Cut the protruding vent off flush with the deck and round the edges a bit.

When its all done the vent is totally solid, its thin on its own but with the qcell, its concrete steady.

   The vented boards lose a handful of foam but they also lose the weight of the 6 plugs and the three fins so I think the vented boards are lighter in comparison.

After the shortboard version Im taking a break from the vents, have a bit of time to comtemplate the results, and then I'll come back from a different angle.

80

Surfoils, sorry for steering you wrong. The board is in: Swaylock’s “Surfshop” under; “One of a kind 6’5” inducted Quad". The guy has all his info posted if you want to E-Mail him.