Need help for fin placement which is troubling me at the moment, the couple of boards I’ve made I’ve roughly copyed the measurements off other boards.
is there a standard rule to it.
I’m new to shaping
Hi,
In order to help you, I need some info about the boards in question: Basically, board model and size, tail width (1' from the tail tip), tail type (squash/swallow/fish/round), and fin setup (single, twin, three, four, five, bonzer, keels).
Cheers Jeff, board size 7'2" -- 21 1/2" -- 2 1/2"
board is size 1' from tail is --14 3/4"-- and tail is about 6 1/2"
squash tail
Thruster fcs fins
also do i need to put a pigment into the plug mix?
There are no standard, hard, fast rules. Only ranges that would be considered “normal.” That’s why there are so many fin systems out there that let you make some adjustment. I’d go about 12" to 12 1/4" up for the rail fins and about 3 1/2" up for the trailer. Rail fins about 1" to 1 1/8" off the rail, toed in 2" to 3" off the nose, with 6 degrees of cant for all around performance.
Hi,
Sorry about the delay (it's the fuse). The pigment is optional, but the final look is better with it. Considering that the tail area is a little wide, I would suggest the following fin placement:
1 - Back Fin - between 3 1/4'' and 3 1/2" from the tail
2 - Front Fins - between 11'' and and 11 1/2'' from the tail
3 - Fin toe - back tip of the front fins 1 1/8" from the rail
- front tip 1/4'' each (for instance, if the distance between the back tip of the fins is 11 1/2'', the fron tips wiil be at 11'' of distance). It almost points them to the nose (little ahead).
4 - Fin Cant - Generally 4 to 6 degree. It depends on the bottom contour, but in general the tip of the fin can't surpass its projection over the rail (check with a 90 degree square)
It's just a general suggestion. In relation to the fin setup, I guess three deeper fins (C5 pattern), or two deeper and one smaller (C3 pattern) can solve the problem)
Keep in mind that it's just a suggestion, and that the experimentation with different fins and a system in which you can play with the fins position will give you a better learning curve.
Good luck!
[quote="$1"]
Need help for fin placement which is troubling me at the moment, the couple of boards I've made I've roughly copyed the measurements off other boards.
is there a standard rule to it.
I'm new to shaping
[/quote]
Hi there,
Since you are new to shaping,
could I suggest you look at an adjustable fin system option like 4 Ways (www.4wfs.com) or even lokbox or pro-box as this will broaden the understanding of your shape and design far quicker than having to make the next 10 boards thereafter with tiny design changes.
Once, u have tried adjusting your fins, u will realize that once you have shaped your board, the ONLY thing that can change the board's performance is the FINS.
therefore it's placement and size is critical to achieve optimal performance for your shape.
hope this helps,
Regards
Deano
My suggestions, in jeffshaper's format
1 - Back Fin - 4" from the tail
2 - Front Fins - between 11 1/2'' and and 12'' from the tail. Further forward (more spread from rear fin to front fins in fore-aft direction) will be stiffer
3 - Rear bottom edge of rear fins should be 1 1/8" from the rail
4 - fin toe-in should be 1/4'' each on a 4.5" base. If you measure the distance between the leading edges of the two rail fins, they should be 1/2" closer together than the distance between the trailing edges of the two rail fins, if the fins have a base width of 4.5". This toe-in is equal to 3.2 degrees.
4 - Fin Cant - I would stick with 6 degrees.
hth. My reasoning is that standard comp setting are 10.5", 3.5", 0.25" toe, 4-6 degree cant, 1 1/8" off rail. If you add somewhere in the neighborhood of a foot in length, you can spread the cluster out 0.5" fore-aft, and move it all forward 0.5". The "sensitive" parameters are the toe-in and the fore-aft fin spread. For toe-in, if you are off by 1/16" you can really change a board, off by 1/8" and you will ruin it. Take a great board, and increase the fin cluster spread by 1/2", and it is a dog. Jeffshaper's numbers will work also, although I think the fore-aft cluster spread would make the board turn quite slowly - but then again - it is a 7'2"!
Blakestah,
well said! spot on!
cheerz
deano
I agree with you Blakestah. Very well explained...
Cheers Guys heaps of help,
Im gona get right on2 it 2day.
I’d like to disagree on the 1/2" spread make/breaking a board. Being one who still works with RedX boxes - I love the ability to move the “spread” by 5/8", or more, by moving, primarily, the center trailing fin in the tri set up. “Up” = looser, “back” = more stable for bigger days. Plus, I can adjust the rail engagement by moving the side fins fore/aft, more/sooner/less later.
agreed!, however i really question the need to move 1/2" apart,
as i know my fin positions in my boards that's where they should be surfed ,
however it's the "minute" changes that make a fundamental difference that counts in the end.
i don't disagree with you, i think being able to move your fin up or down has a huge bearing,
i just don't believe it has to be 1/2" in order to take effect...
with 4ways we talk of 0.5mm movements in toe will have a HUGE effect on the board's performance,
just moving the back fin up 1mm will transfrom your board from something that may feel
sluggish to suddenly alive and responsive..
cheers
deano
Hi Deano,
I showed your website to a friend of mine here in Brazil, and he's interested on bring your system to our market. He's the father of one of our sponsored kids and works in the comercial department of a surfing newspaper. He's really a struggling man, so, give him some credit. Thanks!
thanx Jefferson,
appreciate the connection.
cheers
deano
If the board rides great in the current conditions, and you move the rear fin back 1/2", it will turn into a dog for the current conditions. If you move the fin up 1/2", it will be real twitchy/fast for the current conditions. Its a tighter range than you think…I can explain further…
If I dial in the fore-aft placement so that I can get the most squirt out of each bottom turn, and then I move the fin back 1/2", I can still turn, but I get nearly no squirt at all.
If I dial in the fore-aft placement so that I can get the most squirt out of each bottom turn, and then I move the fin forward 1/2", I can still turn, but it is pivot-y with no squirt.
A quarter inch movement is not quite so offensive, still very noticeable, but will not completely destroy thrust. Once I find the position that maximizes thrust, I never move the fins forward or rearward…the ability to generate thrust is the only thing I care about in the fore-aft position - the key to generating speed.
"the current conditions."
I’d say that is the key I may not have made clear - I’m talking about adjusting the board from a waist high day to a well over head day.
And - I’m not ashamed to admit my body-mind seems to be quite different than many who post here - I don’t notice that huge a difference, certainly not a make or break thing. I don’t always move the fins from one end of the box to the other, and some times I forget to move it “back” from one condition or another, and for me it’s not that big of a deal… Could be the fact my boards are 7’5" - 8’ - 9’ etc… and they have lot’s of volume, so I’m not talking about the 5’+ to 6’+ low volume type of board.
As for toe in - no offence “4-way,” but I’ve read other experts here say it doesn’t matter that much, and I’ve played with far more than .5mm on boards, and I couldn’t tell. I’ll say big changes in cant are a big deal, for me, over 8-10o and I really find a powerful lift, but 4-6o… not much.
In the end - I love the fact that this to me proves there are still mysteries in this stuff… It sure plays within the tolerences of the laws of physics as we experience them in our surfboard designing and riding…
Thanx TaylorO, but i can assure you, adjusting toe-in or out 0.5mm makes a huge difference when riding hi-performance shortboards.
maybe those subtle adjustments on your bigger boards won't be as noticeable due to the "lag" created from the bigger surface area of your board.
I have been making tiny changes for the last 6 years, all of which make a noticeable difference in performance... but then again i am riding 6'0 x 18 1/2" x 2 3/16"
interesting nevertheless tho...
best regards
Deano
Thanks Deano - I’m sure you’re right about the difference in boards.
Plus, for fun, I’ll assume you get to have the best test track in the world… J-Bay… I’m often training on washy reef waves…
Thanks for replying -