Shaping my first board: Single fin - fin design templates?

Hi Swaylocks,

I’m shaping my first board - I’m modeling it dimension-wise after the Channel Islands Rob Machado single fin, as I’ve ridden this board and loved it. I’ll be glassing the fin on, and I wanted to ask whether anyone had any fin outlines/templates I might be able print off and model my fin from? The board dimensions are 6’1 x 20 x 2 3/4 - open to any fin design/size opinions too - I’m hoping to build a smooth board for big arcing turns, so fin-wise I was thinking foiled bamboo at around 8".

This is my first post, but I’ve gleened a ton of info off the board already - cheers!

-p

What sort of fin did the board you rode have in it?  I would scout that out and try to replicate the fin and the placement accordingly.

I have a 6’ x 20" single fin board. The fin is 7.5" not sure of base length! It’s a blast to surf, although it’s a bit small for me now!

 


P-

Fin templates can be found at http://www.blendingcurves.com/temps/fins

Fin design software can be found at http://finfoil.io

Have you considered adding a Bahne (center) box to your board so you can experiment with placements and templates?

Whilst not being a particularly “racey” looking fin, I’ve found this Brewer template to be the best all round performer and most versatile single fin I think I’ve ever used. It doesn’t force its character on you in the way some fins do. It just unobtrusively does its job, and a very good job it does.

 

 

J-

I have considered installing a fin box, however what puts me off from making fins which can fit in a box is the fin base - it seems like a lot of additional effort to get that base correct - however obviously there are significant benefits from an experimental perspective and also a practical one (all my fins have marks/dings from my local which is a rather rocky reef break). 

I did notice in my Swaylocks wandering, someone had made a base which integrated with a custom shape, which is a great idea, however I was unable to find a commercially available product. If I could find something like that, I’d definitely put a box in.

Also the Blending Curves & Finfoil resources are incredible, thank you!

-p

I had one of those many years ago. Alas, a friend borrowed my board and within less than half hour’s use he hit a rock and snapped it. It was a lexan fin and not repairable.

The trick to those Brewers is in the thickness. They are twice as thick as a typical glass fin and thus have a lot more foil. The thickness and foil create holding power that a standard 7.5" does not have.

I still use those Brewer/Parrish/Bonzer fins quite a bit.  I really like the speed and release of the high aspect ratio fins.

I have built a couple of these at 8" to 8 1/2" and 1/2" to 5/8" thickness (wood cores to keep them light).

I find them to have no bad habits at all. Very consistent performers.

RDM,

I am not seeing what is meant by an 8" wide base for this fin?

Hey Stoneburner. I assume the base length of 8" listed on the image is the total length of the base including the fin screw tab and the “nose” extension at the other end. Might be to let people know they need a minimum 8" length fin box for the fin to fit in.

Although the fin actually measures 7-5/8" they rounded up and called it an 8". The term “wide base” referes to depth, front to back, at the base of the fin. It has nothing to do with the size of the box it fits.

So, it’s an 8 inch fin with a wide base, relative to its length. Base is 5-7/8 and length is 7-5/8. That’s a difference of only 1-3/4".

Thanks for clearing that up SammyA.

Mind you, that’s a fair bit of a “rounding off” tolerance they were happy to live with - different times I guess.

Well, 7-5/8" is closer to 8 than 7, so rounding up to 8 makes perfect sense. Maybe they could have called it a 7-1/2. But they didn’t.

Another view of the Brewer from http://www.swaylocks.com/forums/three-fins-70s