Author Topic: Add on board stabilizers...  (Read 12029 times)

Board Stiff

  • Peahi Status
  • *****
  • Posts: 615
    • View Profile
Re: Add on board stabilizers...
« Reply #15 on: November 06, 2015, 07:45:28 AM »
Another design consideration is what happens when you fall off your board...  Do you risk an awkward landing on your outrigger or its arms?

Sent from my VS980 4G using Tapatalk


blueplanetsurf

  • Site Sponsor
  • Teahupoo Status
  • *****
  • Posts: 1896
  • Hawaii's SUP HQ
    • View Profile
    • Blue Planet Surf
Re: Add on board stabilizers...
« Reply #16 on: November 06, 2015, 08:49:37 AM »
I have thought about trying to make a foil SUP for downwinders, like the Flyak but I think the foils are only efficient if they are big enough to lift the whole hull out of the water. 

https://www.youtube.com/watch?v=uO54ZvDwt18
Robert Stehlik
Blue Planet Surf Shop, Honolulu
Hawaii's SUP HQ
http://www.blueplanetsurf.com

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #17 on: November 06, 2015, 09:17:06 AM »
Yugi.. I've had center fins, front steering, rear steering, stepped chines, 22" to 32" in width, and up to 20' unlimiteds. This goes back to 7 or 8 years ago. Narrow is fast. Bigger fins cause noticeable drag. This is just going out of the box a little.

Pono.. I'm thinking a small amount of lift is what I'm looking for, don't think my little single foiled 5" side bites will work. They would be the easiest to modify. I'll look for some cheap 7"ish straight double foil fins and grind a single foil into them. Should I go flat or concave a little? I don't see the concave in the foils I've been studying. Some of them look like a double foil?

Stiff.. Shit happens. This is just a little R&D.

Robert.. I ran through all those scenarios. I will try mounting it towards the nose just to see what happens. My feeling is any amount of real lift will just make the board unstable. I'm just trying to stabilize the board. We're talking 6 mph tops. DW speeds are a whole other story.
 
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #18 on: November 06, 2015, 09:38:19 AM »
After watching Roberts video I realized they were using a 50/50 foil. They used a very wide foil to stabilize the surfski. Here's what I had pictured first, but now I think I need a 50/50 foil. Those will be easier to find and/ or make.
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

marcioferrari

  • Waikiki Status
  • *
  • Posts: 42
    • View Profile
Re: Add on board stabilizers...
« Reply #19 on: November 06, 2015, 10:44:14 AM »
What about installing two fins horizontally somewhere in the front part of the rail, like shark pectoral fins? Probably at zero angle to avoid drag, or at a small angle to create lift (increasing drag). It may help stability without compromising turning ability. With fin boxes you could change fins sizes as well.

Pierre

  • Sunset Status
  • ****
  • Posts: 300
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #20 on: November 06, 2015, 11:55:58 AM »
After watching Roberts video I realized they were using a 50/50 foil. They used a very wide foil to stabilize the surfski. Here's what I had pictured first, but now I think I need a 50/50 foil. Those will be easier to find and/ or make.
Awesome idea. Thanks doig the test I'm dreaming about since years ago :D
\HF/- Hi-Fun Hydroworks / custom boards,BZH, since 1982  /  *Link Removed*

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #21 on: November 06, 2015, 06:11:18 PM »
After studying a bunch of wake boarding foils I decided to go with something like a 90/10 foil. So it's almost flat on the bottom side. I grabbed some scrap foam and free handed some curved opposing foils. I glued them to pieces of divinycell. I figured that would make a better mounting base that I could screw to. Any comments regarding the foils would be welcome. I can still fine tune them. As I glued them I check both of them to make sure they were on a neutral plane.
« Last Edit: November 06, 2015, 06:13:09 PM by TallDude »
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25864
    • View Profile
Re: Add on board stabilizers...
« Reply #22 on: November 06, 2015, 06:17:51 PM »
Probably too big, but what the heck.  give them a go. I'd probably grab a model airplane wingtip and cover it with carbon. One of those foam gliders. Maybe PM great dane and see how far they took the effort.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #23 on: November 06, 2015, 06:31:43 PM »
They're about 21 sq inches, but I figured I'd set it for maybe only 60 % submerged to start. I will be able to adjust them up or down, in and out, fore and aft, and lift angle. Do you think they should be thinner? I'm in the range of what I was seeing.
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25864
    • View Profile
Re: Add on board stabilizers...
« Reply #24 on: November 06, 2015, 08:26:10 PM »
Start with what you've got. Most angled wing foils use a lot of tape to the wing tips, the reason being that the amount of lift per inch of submersion changes quicker than a straight wing, so if you tip the board you get a bigger stabilizing force--the side coming out of the water loses more lift, and side pushing down gains faster.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #25 on: November 06, 2015, 08:35:46 PM »
They get a little thicker the closer to the mount. That will probably just slow it down, but it's a starting point.
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

jrandy

  • Sunset Status
  • ****
  • Posts: 489
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #26 on: November 07, 2015, 05:11:02 AM »
TD-looking good, thanks for sharing. I hope we get more pictures and a ride report. This reminds me that I have a kayak skeg that I should rework from thin and flat to thicker and foiled. -J
http://pushheretosavealife.com/
Be safe, have fun. -J

SUPflorida

  • Peahi Status
  • *****
  • Posts: 720
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #27 on: November 07, 2015, 07:27:50 AM »
Wouldn't something along this design path provide a practical solution...scaled down to fit your unlimited...maybe not as exotic...but certainly would get the job done. Four windsurf foot strap insets to fasten to the board and it would give a strong/secure attachment to your board that would easily enable you to take it on and off at will.

http://www.huki.com/index.php?page=Gull_Wing

 
« Last Edit: November 07, 2015, 07:37:59 AM by SUPflorida »

TallDude

  • Cortez Bank Status
  • *****
  • Posts: 5714
  • Capistrano Beach
    • View Profile
    • Email
Re: Add on board stabilizers...
« Reply #28 on: November 07, 2015, 08:15:27 AM »
I had actually thought about that years ago and talked to Jude from Huki about those dragon outriggers. Jude was in the process of designing some SUP race boards, and he was looking at an old unlimited I designed at a race. It would have to be a very small version and would probably feel like and anchor when they hit the water. Might even throw you off? These foils would be in the water constantly so there immediate change in drag. Eventually I am planning on adding some screw attachments like the ones for windsurf foot straps. 
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25864
    • View Profile
Re: Add on board stabilizers...
« Reply #29 on: November 07, 2015, 09:10:16 AM »
Yeah, it would be horrible. Doesn't work that well for the boats, and people are sitting in them. I know a guy here on Maui who tried one because he was struggling with his surfski, but took it off after one day.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


SimplePortal 2.3.7 © 2008-2024, SimplePortal