Messages

151

Foil SUP / Re: Is GoFoil the Only Option?

« on: February 20, 2017, 08:33:40 AM »

the issue would be the turbulent surface region on wind chop, makes control quite difficult and can demand some fairly large weight movements on your feet let alone on your ass while trying to paddle
if the foil is within 200-300mm of the surface you are affected quite alot by the waves and then add to that the weight and leverage of a ski swinging round out there infront and you will see why it hasnt been done. something like this is extremely hard to fly on your feet, now try sitting down!

152

Foil SUP / Re: Diy sup foil

« on: February 14, 2017, 09:28:17 AM »

How much pull is on the rope?  The strain on the rope should be directly proportional to the Life/Drag of the foil.

For example a Lift/Drag ratio of 10:1 would be a relatively low performance Airfoil. This would suggest 85 KG of lift producing 8.5KG of drag or 18.5 lbs of pull on the rope.

Given that 'you' appeared to be using 1 hand this would seem accurate.  (excluding form drag which might still be low at 3 - 8 knots).

I'd say more like 10-12kg+ with the new foil, mainly cause it is horrendously unfair on the underside and has a leading edge like a golf ball... i like to structurally test things before getting carried away with finishing  the old thin foil at around 8mm thick had next to no drag on the rope once you got up at maybe 7-8kts, the tow line was slack most of the time even behind a 10ft dinghy with no wake to speak of.
in light of petrol prices here in NZ we are now conducting tests under sail, much better with no prop wash

153

Foil SUP / Re: Diy sup foil

« on: February 13, 2017, 12:28:10 PM »

Looking good! Man that machine would make life easy. Do you set stainless into the Tuttle box for tapping into or just straight into the carbon?

154

Foil SUP / Re: Diy sup foil

« on: February 01, 2017, 06:45:36 PM »

I don't have the foil with me but at a guess the main foil would be over 5 but less than 10 degrees, and the stabilizer about 7 at the root washing out to about 2 or even 0 degrees at the tips. There is a lot of room for improving here so I am making a new adjustable stabilizer with more area and a nicer section shape

155

Foil SUP / Re: Diy sup foil

« on: February 01, 2017, 07:01:00 AM »

yup its mint, no flex in this puppy. super thick is the way to go the lift this thing produces is unreal although 10kts is about as fast as you can go before you really notice the trailing edge separation. heres a couple of vids first one is after about half an hour of riding it and second one is my 85kg brother taking off at 3kts the next day. I weigh less  (75)and was getting up even slower but unfortunately no one got it on film

156

Foil SUP / Re: Diy sup foil

« on: January 31, 2017, 12:49:59 AM »

well its not a sup, and it was behind a boat, but she will fly at 3kts(!) with 75 odd kg onboard! now we just need 30kts to try it out on the sup.

157

Foil SUP / Re: Diy sup foil

« on: January 24, 2017, 10:21:28 PM »

anything piercing the surface suffers a drag penalty, especially an adverse pressure inducing foil!

158

Foil SUP / Re: Diy sup foil

« on: January 24, 2017, 08:45:26 AM »

flexi foils is what we need! shaped with wash in at the tips for extra lift in the pump, then when your weight comes back on it will flex to have wash out.
this was the idea with my whale tail foil but i may have built it too stiff, stand by for results!

159

The Shape Shack / Re: 25 1/2" x 13' flat water board

« on: January 20, 2017, 08:27:57 AM »

supuk throw up some pictures!
the whale tail is just hand shaped polystyrene/carbon. currently the foils have female sockets and a long threaded rod that goes through the front foil and into a nylock nut set into the socket on the rear foil, this worked great but without a vacuum pump my sockets are too resin rich and they have worn out somewhat so this new one will just be glued together.

160

Foil SUP / Re: How to..

« on: January 20, 2017, 07:31:13 AM »

why wouldnt a standard board be ok for a foil?

161

The Shape Shack / Re: 25 1/2" x 13' flat water board

« on: January 15, 2017, 07:56:58 AM »

moulds would be the way, are you hand shaping yours?
heres my latest foil, huge with flexible outboard sections for ultimate pumping power... thats the idea anyway . the current one on the sup is way too small to work on a downwinder. a 13ft board is quite a bit harder to fly than a 6fter so we have found!

162

The Shape Shack / Re: 25 1/2" x 13' flat water board

« on: January 14, 2017, 02:27:49 PM »

cheers, mast has an 8mm foam core. those bumps look cool but i think they are nothing but drag

163

The Shape Shack / Re: 25 1/2" x 13' flat water board

« on: January 14, 2017, 06:46:14 AM »

and yes of course its got a foil it is 2017 after all!

164

The Shape Shack / Re: 25 1/2" x 13' flat water board

« on: January 14, 2017, 06:44:40 AM »

couple more

165

The Shape Shack / 25 1/2" x 13' flat water board

« on: January 14, 2017, 06:43:15 AM »

thought i'd share the board my brother and i recently built for flat water/ downwinding. decided on 13' as we have found 14' is too long for the short harbour chop we get here and the extra length over 12' 6 is nice in the flat stuff. full carbon construction with an as yet unfinished steerable fin set up for those cross wind days