Anyone have a look at “the simster”? Curious about the fin placement and toe/cant of the rail fins.
http://www.theswiftmovement.com/Catalogs/Hydrodynamica_Test_Pilots_2010_Brochue.pdf
scroll down a bit to “tri fin planing hull”
howdy pico,
check out the other simmons-centric threads here. i clearly remember seeing one particular thread within the past 6 weeks or so with the fin placement you’re after (except it did look like a quad setup ?). if i could only remember the thread title hmm
cheers,
been searching… no luck. twin keel (rocketfish template) and a trailer. I’m really only concerned with angles and placement of rail fins. The trailer will probably go at 3 1/4".
Ok well my thoughts are to put the rail fins @ 10.5" from tail, 1 1/4 off rail toe in 1/8, minimal cant, and the trailer at 3 1/4". Does this sound objectionable to anyone?
hiya Pico !!
" when in doubt , TRY it out ! "
and educate us with the results [and photos? ] , please ?
that [ well, to me , at least ? ] is what Swaylocks is all about ...let's learn from each other , EVERYONE has SOMETHING positive to contribute here !! ....
cheers !
ben
Here is the board in question. All my accurate measuring devices are in the shop so I can’t give exact measurements other than 5’6"x20.5"x2 5/8". options options.
wow!
those inner concaves remind me of the ‘suspended stringer’ setup i’m planning to do on my next HWS hybrid, a simmons quad. good to know the idea looks that good in 3D form " )
btw pico, the thread i recall having the fin setup you need is probably within the first 3 pages of the general discussion list, too bad i’m having senior moments lately tsk tsk
cheers,
woohooo cheers mate !!
.....you never mentioned anything about "wicked curvey channels" , you bundle of surprises , you !!
I hope , having posted that shot [THANKS mate !] , that someone with waaay more fin setting experience and clue than me , will chime in to help you ?
cheers !
ben ' I am just a tinkerer ' chipper
" when in doubt , TRY it out ! "
I think I’m gonna go with that! Wait till you see the fins chipper. I love making fins these days. Anyway, lots of ideas in my head waiting to be freed!
"Wait till you see the fins chipper "
...I look forward to it !
The first thing I thought when I saw the photos of those channels ...was...
....'Erle Pederson ... jet bottoms and fins !!!
I would LOVE to see someone else make some fins like HE made , on his jet bottom sculpture boards ??!!
1770 , I think , is his website ?? ...'pandanus' , you're near there , yes ?
do you ever see his jets around your neck of the woods ?
and those spacey , spacey fins ??!
cheers
ben
never seen anything like THAT anywhere!
got a pic of the fin?
hows the ride?
spaced out!!!
Hi Pico,
Check this one for jet bottoms and great fins:
http://www.surf1770noosa.com/erle_pedersen_jet_bottom_surfboards.php
Are you interested on some measurements on this board?
http://www.quivermag.com/boards/soul-power-2007-0
It’s a sort of twin with an option for center fin and 2 little quadish sidefins.
Take the waterflow in the channels into consideration with fin placement to not obstuct but increase and positively redirect it.
Check out how Erle has tackled this.
Remember to put the finished board in Quiver with a ride report.
Happy surfing
Sjoerd
Thanks Soulnpower. This photo is very interesting. No cant on the rail fins and all those little fins on the high spots. I’m glad I didn’t see this before I started shaping. My mind is blown, just trying to imagine the water flow against this bottom. Wish I could get a profile shot.
I have the same question in regard to the tri-fin simmons planing hull. I built a wooden one but I’m not happy with my fin set up. I used a small centre fin for a little bit of stability (the board is only 5 foot 6 inches so it thought it might be an advantage) and rasta keel copies for the outer fins. The board felt good but I felt like I was turning around the kees rather than turning the board! Can anyone share some numbers in regard to this set-up?
hi 'mitcho' !
what is the board's width , and thickness ?
can you post up some photos of the board and fins , please ? [is it fairly flat , with thick rails , for instance ?]
THAT will all help .... cheers , mitcho !
also , what size / kinda waves are you riding it in ?
lastly , what is YOUR size ? [ in inches and pounds , if you're not into kilograms and metres ?]
I've ridden cutaway keels , with a small trailer , in the wide-tailed Walden 'CD4' [a five fin option board] that I have . The size of the back fin , and where the keels were , made a big difference , I found , on the few surfs I had this setup on....
cheers !
ben , west oz
Hi Ben.
My Board is 5’6" x 23 x 2.5. (1 foot from nose 19", 1 foot from tail 19 1/2") Tail block is 10 inches wide. Rails are high and pinched at the nose going into 50/50 for the more parallel section of the board, into downturned and sharp for the last 20" of the board. She’s a bit of a classic Simmons inspired planer with a bit of belly in the nose, super flat through the remainder of the board with a slight concave through the tail. A few inches of nose rocker and very little in the tail. I’m 5’8" and weigh 75kg (metric AND imperial!). It’s a hollow wooden construction and looks a bit “back yard” but I’m really happy with her. She paddles FAST and duckdives really well. I think the mixture of volume and weight has worked out well as the ride is stable and not too chattery. I surfed her in sucky head hight French beachies last year and she flew. There’s a fair bit of tail volume too which really seems to help in catching waves. My problem is my turns. Once initiated, around she comes but because the fins are so far forward I feel I’m turning around them. It’s not the flowing transition of power and direction I’m looking for.
The rear fin is 3 1/4 h x 3 1/4 base and is 1 1/2 off the tail.
Keels are large at 5"x5" and are raked back considerably. They are set (trailing edge of base) 15" from tail which I think is my problem. It’s an experimental board (for me) and I was looking for planing speed mixed with the manurivability of a thruster. I made a mistake in the build and set the wings too far forward (11 1/2" from tail) so in turn forced the fin placement forward! Another problem, I think, is the amount of toe in. I used the old addage of a couple of inches outside the nose for toe in, but as the nose is rounded and foreshortened in the traditional sense of a pointed nose, I now realise this was also a mistake. Looking at the board you can see how much drag must be induced by this amount of toe in!
My plan is to cut off the keels, extend the wings further back on the board and re-attach the keels (or refoil another set of smaller front fins with less surface area). Extending the rail line isn’t a bad thing on a board so short and hopefully by bringing the fins back and tightening the fin cluster I’ll be getting more towards the feeling I’m after.
I get 2 weeks in French beachies each year but the majority of the time I surf in UK waters. Sometimes it’s the sucky powerful stuff but normally less powerful and mushy surf, so this board is a real all rounder.
Based on all the above, do you have any thoughts?
Any input appreciated!
With Thanks,
Mitch
mitcho, use those same fins but move rail fins to 10 1/2" from tail, 1 1/8" off rail, 1/8" toe. 2 degrees cant. 3 1/4" off tail for trailer. we have similar dimensions and I love this set up.
Thanks mate. I have a little work to do. It’s going to be interesting to feel the difference the reconfiguration makes. I’ll get them fins relocated and post pics when I can. The interesting bit will be extending the rail line and pulling the wing a further 4 inches back! I’m glad I’m working with wood. Thanks for the feedback, it gives me a solid idea at least. It helps you have a similar board. What waves do you ride it in? What’s the characteristics of riding it?
Thanks so much for the info, it’s really useful and gives me a bit more confidence.
Good fun 'init!
Ex-Tassie boy.
Mitch
hiya Mitch !
[ at least , as a Tassie guy , the English water may not feel THAT freezing to you , eh ?!]
Thanks for the photos ! Interesting board . Nice wood.
It looks like it 'could' be a 'twin keel [or 'half-moon' fins ] simmons' , with that width and outline .....???
I'd be interested to hear your thinking on 15" forward fins , with a trailer almost on the tail .
And if you were going for kind of a thruster option , are you able to plug it now , or would it be too late ?
I ask , because with the wings 11" up , you 'could' always place the fin plugs there ?
and a couple of back plugs [? or probox ?] , or maybe even a small single fin box ? just a thought !] at 3 -3 1/2 up from the tail pod ?
just some thoughts ...I guess you need to work out if you want it to surf like a simmons [with that outline , it's a distinct possibility it WILL , anyway !] or if you are really wanting / expecting it to surf like a thruster [which it may not do , fully]
do you prefer / favour / surf with trim , glide , and more drawn out turns , or are you a more top to bottom , whack the lip hard , shorter radius turn , type of surfer ?
what [types of] board do you most often ride [eg: 6' thruster , midlength , mal , fish , or ....???]
cheers mate !
ben , west oz
Hi again Ben.
I was tempted to make a copy of the now classic casper but having ridden a quad fish for a while I wanted to get back to the thruster feel. So the Simster incarnation had obvious appeal! A wide Simmons outline with a good aspect ratio, a pulled in tail (maintaining the 10" width as per Bob Simmons) and a thruster inspired fin cluster seems like a good idea! Riding a lot of junk or weak waves meant that the planing quality was desirable. Having just turned 40, the paddling advantage and wave catching ability were a boon too.
The fin spacing was actually a mistake. As I said, I cocked up the wings by putting them too far forward and felt the side fins had to go with them. I thought the rear stabaliser should go on the tail for maximum benifit as the board is so short. Oh well, it was worth a try. You live and learn, and a practical lesson is best. This kind of tweaking is pretty cool I think any way.
If I put the fins right on the wings they would hang way outside the rail line of the board because they are swept back cut away keels. Not a good idea really as I’d constantly be injuring myself on them! That’s why I was thinking of foiling up some more, less keel like fins. That way I could move the fin base back without the fins hanging out past the rail. I think I’ll just extend the wings back where I designed them to be and reuse the keels as you suggested. They are set at 2 deg cant now and I’ll stick with that but your 1/8 inch toe in should work a lot better. She certainly will fly! Perhaps moving the rear forward will help with the more vertical (attempts!) turns by allowing the tail to dig in a little and scrub off a little speed? Just a thought.
I’ll stick with the glass on’s over boxes. Fin Boxes are a little tricky at this stage. I can always cut them off again!
What do I ride? Well, the modern quad fish. It’s fast and a good wave catcher but I can’t get it to do what I want. My old board was a Pacific dreams 6’1" thruster with a mad bonzer style bottom. It was the best board I ever owned but I’m just too heavy for it now. SO hard to catch waves and it’s really boggy in UK waves. I tend to surf as the wave allows. Flow and trim when I can but if a section looms I want to hit it. Carving cutbacks are a particular favorite. We’ll just have to wait and see how this rides. Like you say, you cant get away from that outline and rocker, it will plane! Hopefully there will be an element of that lose drivey snap too.
How about you (sorry to hijack this thread!)? How do you find the Walden?
Cheers,
Mitch