I’m normally pretty careful about symmetry so in theory I guess it shouldn’t matter which point of reference I use. Still, I would like to know. I know some people measure their placement for a rail fin off the center and others work off the rail.
With a board that has a minor and unintentional difference in the template from one side to the other, is it better to measure for rail fin placement from the rail or in relation to the fin on the other side of the board?
I goofed and borked my centerline reference on a stringerless and wound up with a little deviation in the tail template on the last quad I made.
I measured my fin placement off the rail…it seemed most appropriate for that type of fin setup.
All things aside
rail fins are set off the rail
but
if you know the symetry is correct then from center will achieve the same end results
no matter what,, I go off the rail
off the rail...
my thinking is : the fins are interacting with the rail, not the stringer.
Off the rail, stringers are off when the cut for them is slightly tilted or even curved a little.
As mentioned, interaction is with the rail...
Off the rail for thruster side fins and quad fronts… between the fins for rears on quads.
…always from the centerline…no exceptions !
herb
…always from the centerline…no exceptions !
herb
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care to elaborate?
**supply some logic ,your thinking route, etc.
**
ya,it’s the only correct way to set sidefins.
if you’re uneven from rail to rail from the centerline measurements, ,it only means one thing…you’re shape is off.
you get a symetrically even fin set by using the centerline for your sides…plus you will know if your shaping is up to par…also it is far better to have correct fin positioning than it is to have one that only looks correct…but isn’t…trust me on this one…jimmy phillips has backed me up on this very subject before…right here at sways!
if you use your rails…and your shape is off…even a little bit…your fin set is asymetrical.
herb
But if it’s not… they won’t be.
ya,ya,ya,.
herb
Well thanks for the reasoning, cant say you sold me.
I’m as likely to have a finished shape being slightly off as I am towards total symmetry.
I just place off the rail where fin positioning relative to the rail seems most important to me.
Although I can understand a production guy where symmetry is a requirement and habit, sticking to your system
as part of the self verification process and shooting for idyllic symmetry all the way through and through.
This forum is getting tedious with some of the posters eh?
Thanks
otis,
do you use a sureform when you shape ?
herb
bingo!
machine shape , heavy finish work with sureform and sanding blocks,
lots of scrubbing.
otis,
i thought so.
got a tool here that will cut your time in half,and eliminate the sureform…for the most part.
you interested ?
herb
interested? yes
I havent been using a planer because I have an apt. garage that frowns on doing work
or projects in the garage-- a storage only kind of thing. As long as I’m quiet and discreet, we all get along.
No offence intended Herb, but I’d argue symmetry is way over rated.
Some things matter more than others.
let me put it to you this way,from a car racer’s point of view(excluding stock cars ,which are set-up for turning one way).
if your car frame is off/bent,and you align the wheels to the steering…what happens ?
it steers correctly in feel,but the car tracks a bit to one side or the other,causing drag and loss of speed/movement/control thru turns.
samething with a surfboard,man.
unless you are trying to go asymetrical… i don’t…at least in this case,
…your board will track in an off center pattern,causing drag.
even a little bit ?
yup!
herb
otis,
i wish i could post pics,three simple hand tools that i use that cut my time drastically.
one: is called a sanding board used in automotive repair.it’s about 18" long and 3" wide.cuppled with 36 grit paper it eliminates loads of work.
two: the next and most important is a metal holder for dragonskin.this little handy tool will easily replace any type rasp or sureform with more speed , control,and a cleaner net surface.
three: is a piece of kickboard foam approx.1" x 3" x 18" that is soft enough that you can literally rap it aroung the rail ,but stiff enough that you can sand contoured decks out with.
I HAVE LITTLE OR NO USE FOR A SUREFORM ANYMORE.
EXCUSE MY KEYBOARD…IT’S HAUNTED !
HERB
Thanks for replying Herb - For fun, and with the hopes of learning, I’ll keep arguing.
I think the race care stearing analogy is faulty - the board doesn’t turn, nor is it ridden (with little excepetion) flat. And, drag, as it is induced by the toe-in of the fins, would seem to have very little to do with how near or far the rails are from center in relation to each other.