MX 14 Fin

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David L Alston
Posts: 72
Joined: 24 Jul 2012, 17:38
Sail number: 3011
Club: Leicestershire RYC UK
Design: Fatboy

MX 14 Fin

Post by David L Alston » 16 Oct 2014, 15:28

I need some help please.

The MX 14 has a rectangular fin box and the fin transitions to rectangle at the hull... Ok

So when I put the fin in the fin box the step of the transition is more or less flush at the front but the is a 2.5 mm step / gap at the rear.

Clearly this is most undesirable and will have an adverse effect on performance and my winning the world championship next year.

So the question is

Is the fin box incorrectly fitted and raked forward

At the moment the fin appears to be raked at 0 degrees if I use the datum water line as the transom edge and the point on the bow where the bumper ends on the hull.

If I were to correct the fin so it fits flush with the hull - the fin would be raked back about 6mm of vertical for the same water line datum.


I could leave the rake as it is and simply flare the transition step to meet the hull.

I do not know where the design datum line actually is.

Clearly the boat pitches forward -

What do you think ?

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