Forensic Fin Help

General Discussion
1

I have this old board in my garage.  I don’t know anything about its origins, but I do like the way it rides.  I think it has a lot to do with the fins.  I am looking for some help in figuring out how to replicate this fin setup in an FCS dominator, which has the quadverible setup or an FCS thruster setup.  I know it’s a quad because there were 4 fins, but the small ones are on front and large ones in the rear.  I measured the depth and base.  The large rears are width: 5 depth: 5.5 small fronts are width: 3 depth 2.75. Neither fin has foiling on the inside.

Any help is appreciated.

Thanks!

[img_assist|nid=1052452|title=Forensic Fin Help Side|desc=|link=none|align=left|width=100|height=75][img_assist|nid=1052451|title=Forensic Fin top|desc=|link=none|align=left|width=100|height=75]

 

 

2

Hi garagedweller, Your pics look to be a Twinzer set up. You will never be able to copy that in the FCS Dominator. Sorry placements are wrong to start with and FCS has no adjustment to even come close. If you us the same fin outlines and place the small fin in front and large in back your board will be stiff. Hope this helps my friend. Mahalo, Larry

3

Thanks for the reply.  I now have the proper vocabulary when talking about the setup.

 

4

garagedweller, I think this is the modern version of what you were looking for. Thought I would share a pic. Twinzer set-up can be done with the right finsystem. Mahalo, Larry

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5

great example Larry ! 

any other pics of that twinzer  :slight_smile:

6

Heres one of Martin Potters Twinzers I picked up, signed,

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/Surfboards026.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/Surfboards025.jpg[/IMG]

And one of his 6'2" Glen Minamis from 1989,

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/Surfboards032.jpg[/IMG]

and one of his big boards, 8'5", 3" thick, maybe Wiamea ?

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/Surfboards028.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/Surfboards027.jpg[/IMG]

If you want closer pics of the fins and dims I can supply.

 

7

details on the potz twinzer !!!

i need to try something like that as my next board

8

[quote="$1"]

great example Larry ! 

any other pics of that twinzer  :)

[/quote]

 

 

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9

Yeah bring it on mate !

Full surgical dissection of the Pottz twinzer , please !

10

Guys, I'll do it later today. Dont touch that dial !

11

Hey Surffoils, What's the bottom shape on the Pottz twinzer, please? The fins look like they're placed further up on the Pottz compared to the other twinzer images on this thread, any ideas why that might be? I'm going to put a twinzer setup on a 5'7 lis style fish I'm currently hacking, so am keen for any info that might guide me in the right direction

12

Placement has to do with drive, here's a Belik Fish with set-up back. On a more pull in Plan ship like a Twin Fin the placement can be more forward.

Simple concept(-:

Mahalo,Larry


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13

To the guys who were after a disection of the Twinzer, heres the pics,

The grid is in cms because inches are evil.

Overall the board is 6'2", pretty much the same size of short board that Potter rode.

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA054.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA055.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA056.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA057.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA058.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA059.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA060.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA061.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA062.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA063.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA064.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA065.jpg[/IMG]

[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SurfboardsA067.jpg[/IMG]

 

I'll post up specific dims about the distance between fins, distance from rail and stringer etc.. tomorrow.

And if anyone has any other questions, Im happy to answer.

Robb asked about the bottom shape---Its Vee all the way., totally EVEN vee from nose all the way down to about 30 in from the tail and then it increases. If you want pics and dims for true detail, I can do that too.

More pics of some of my boards (25) are at.. http://s153.photobucket.com/albums/s225/SURFFOILS/

 

 

 

 

 

14

Orsome.

Rocker would be neat.

I'm really interested in 80's rockers - any rockers for that matter.

Good photo file there , got lost in it for a while.

15

OK so for some details on the pics

the grid is in cms..

 pic 1 is the outside fin

2. is the inside fin

3. is detail of the trailing edge of the inside fin

4. is detail of the tip of the inside fin

5. is detail of the leading edge of the inside fin.

6 is detail of the line between the tip and leading edge of the inside fin.

7. is the distance, 45 mm, between the front of the leading edge of the outside and front of the inside fin

8. is the distance 42 mm between the fins at the back of the outside fin.

9.  is the same 'theoretical' distance but with the ruler perpendicular to the stringer.

10. is the distance , 46mm, of the outside fins leading edge to the rail

11. is the distance,   24mm , of the trailing edge of the outside fin to the rail

12. is the distance,40mm     , of the trailing edge of the inside fin to the rail.

13. is the distance 143mm, of the outside fins leading edge from the CENTRE of the stringer.

How boring is all that, but essential if you want to copy a Twinzer.

16

Wow, thanks, Larry and Surffoils. It's all fascinating to me and infinitely useful in working out a setup for my board that'll work. If either of you have the time, could you let me know what kind of cant is involved on the fore fins?
And just out of interest is that Pottz twinzer a Minami like the others or is it a Jobson?

17

[quote="$1"]

Wow, thanks, Larry and Surffoils. It's all fascinating to me and infinitely useful in working out a setup for my board that'll work. If either of you have the time, could you let me know what kind of cant is involved on the fore fins?
And just out of interest is that Pottz twinzer a Minami like the others or is it a Jobson?

[/quote]

 

Robb, 14 to 18 degree cant is the window of performance for the fore fin. If the fin is to vertical it will interfear with water flow to the bigger pivot fin and stiffen the board. More cant does not hurt performance. Mahalo, Larry 

18

 

Larrrrrbles,

That box config looks like it would work for the standard quad setup too given how for the twinzer the cant/placement seems to be achieved by the tab offset.

Does this mean I can make a board with four boxes and ride it as a quad or a twinzer given the right fins?

(Please say no, I don’t need another project right now!)

19

[quote="$1"]

Wow, thanks, Larry and Surffoils.
And just out of interest is that Pottz twinzer a Minami like the others or is it a Jobson?

[/quote]

 Probox-Larry knows all the fin magic, Im just a guy with a ruler.

My Twinzer is a Stuart D'Arcy, I believe he was Pottz shaper when he was living in Australia. Its got a decal that says...

" Designed and surfed by Martin Potter Shaped by Stuart D'Arcy"

 I'll get some more dims off it and post later.

20

[quote="$1"]

[quote="$1"]

Placement has to do with drive, here's a Belik Fish with set-up back. On a more pull in Plan ship like a Twin Fin the placement can be more forward.

Simple concept(-:

Mahalo,Larry

[/quote]

 

Larrrrrbles,

That box config looks like it would work for the standard quad setup too given how for the twinzer the cant/placement seems to be achieved by the tab offset.

Does this mean I can make a board with four boxes and ride it as a quad or a twinzer given the right fins?

(Please say no, I don't need another project right now!)

[/quote]

 Sorry afoaf, I guess a new project is going to in works for you.

Yes afoaf, that is exactly right my friend, the same board can go into Quad style. Thanks for the kind words surffoil.

Same 3 boards from Twinzer mode now to Quads. Funny what a true fully adjustable finsystem can do with NO LIMITATIONS.

 Mahalo, Larry

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