Hi Craig, thanks for the question and suggestions, so far the best improvements have come not from me but from others so I welcome everyone’s help and ideas.
I’ve tried using 2 struts, one behind the other and also side by side. On big foils Ive even used 3 struts but in the quest to reduce weight drag and complexity I’m trying to keep the number of struts as low as possible.
As for strut flex, I never knew or suspected that the struts were flexing ! It was only when I saw the video of the longer struts that I saw what was happening. I don’t think the flex is a bad thing for performance but it does bring up the exciting possibility of getting more speed and projection. The flex from the struts isn’t vertically up and down like a surfboard but sideways and more like how a fish moves thru the water.
The best future design I can see will include several elements that seem to work smoothly in all situations and at the moment I think it will have 1 or 2 struts, shorter rather than longer struts and more than likely the struts will be made of aluminium just like the struts that Laird uses. Or maybe a compsand Carbon layup down the track…?
The overall depth of the foil is crucial and dependant on the strut length and the foil design itself. Looking at the last yellow foil the struts are 12 inches but the foils active surfaces are 16 inches deep which keeps the rider higher and experiencing a better ride.
Thanks for the idea of connecting the perimeter stringers to the outer flanges.
Craig, I’m always happy to chat here or back and forth thru PM’s as a lot of guys are doing or email. surffoilsmail@gmail.com
I showed one of your clips to my eight year old son, who is more interested in tennis and skateboards than surfing at this point, and he immediately asked if we could make a board like yours. Thank you for giving me an excuse (other than my own selfish pursuits) to spend more time tinkering in the shed and playing in the water!
I believe rider weight must enter the foil size equation. Surffoils is still experimenting. But I suspect foil shape, number and placement could create different effects on performance. I think average board velocity will determine foil specs and performance also.
Don’t think this is a one size fits all type thing.
Surffoils, when I’m not working I am in Australia, Tweed area of NSW. I can think of a few waves around here that would probably suit this kind of surfing…
yes it DOES 'sound' complex ... lots of variables , eh ? [without even factoring in every WAVE being different , too , of course ?!]
I guess the more you test them in a consistent wave , the more you will get the idea[s] of what does what ...
How it FEELS while surfing is about all I have to go on , testing my 'normal' fins on [pretty much ] the same board[s] , all the time .
keep up the mad science ! It is interesting , 'outside the box' , and entertaining , all at the same time .
I'm glad you have taken photos and footage of the process / progress so far .
It's always nice to be able to SEE what's going on , as I learn / keep interested with VISUAL input , mainly . [Which might just be why I too take ...er... "the occassional snap" , myself ?!]
probably where a long[ish] finbox to somehow attach it to , will be a help , yes ?
I eagerly await THAT day coming , and shots of it being stand up surfed ...do you think it is time yet , or do you want to keep researching the foils more , first ?
I guess you will need a longer bracket out the front of the board , to get all the wave , the foil , and the [upright] rider in the picture too .
How are you progressing on the surfboard to mount the foil on , any luck ?
the plan is to keep foil, s are a little widr too the yellow foil in some tThis gives the work on with the front working main and th more lift andu turns.
Bwd, a member here, suggested rotating the delta fin around and I tried it. With the wide arms at the front it stabilised turns and held in better thru bottom turns. It was a good lesson to try things in all ways. Thanks Bwd !
Even after a few surfs, its clear the thinner arms are better because they ride within the wave better.
Also any connecting arms are better being more horizontal. Any surface provides lift at 90 degrees to the main axis so vertical arms “lift” sideways , whereas the more horizontal arms lift vertically.
The outline dictates how it orientates to the face of the wave, a narrow nose shape sits with its nose turned into the wave, whereas the wider nose foil turns more away from the face.
I think a slightly wider nose like this is the way to go for the next prototype.
Long thin arms, reduce the number of connecting arms to the central beam and the central beam needs to be changed.
And of course, all of this will need to be changed when I move to stand up.
