Surffoils. Were you thinking of an insert something along the lines of this sort of thing?
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/INTERNAL_FIN_GROUP.JPG
Or something like this where the water flow actually exits on the deck of the board?
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/INTERNAL_FIN_GROUP_2.JPG
I’m loving this thread!
This kinda stuff keeps me motivated.
Remember,
If you are not innovating,
you’re probably imitating.
Keep it up guys!
It would be easy enough to 3D print an insert like this to add into the bottom of a board.
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/INTERNAL_FIN_GROUP_3.JPG
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/INTERNAL_FIN_GROUP_4.JPG
Hi Rohan, yes that’s real close to what I had in mind. Last time I did all of this I learnt several things…
Keep the ‘holes’ as small as possible, width doesn’t work. Gouging big holes in the bottom takes away from the planing area that’s critical near the inside rail.
Stagger the holes / slots with the central a Drive ones closer to the stringer and further back, and move the Pivot slot up and out near the rail.
Inside the slots use hardware to moderate the flow and let it exit out the deck.
Heres mine from a few years ago… still ride it on fun days … get some great looks when I have a couple of jets of water flying out the back!
How’d it go.?
Here’s what happens with a foamy with the fins removed and water squirting up the holes !
Edit…Unable to post pics today for some reason ??
i know that it is not going to be the same feeling as riding a thruster , but we ll see, that feeling come with the vertical fins clawing water …FIRST CUT IS THE DEEPEST
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/innovation%20control%20sys.png
Surffoils is always a breath of fresh air. Find his port/vents thread from a while back; really interesting. And those surf mats…
Glad everyone’s trying stuff, but any sort of hole in the bottom is doing exactly that, putting a hole where there should be planing surface. Just trouble… and no fin to help at all…
I’ve always wanted to do a nearly symmetric board with a very kicked nose and tail. It’d have a preferred direction, of course, but it would maybe be more complaint to be ridden backwards. A very kicked tail into an otherwise flat rocker would make it really easy to pop 180s, ollies and whatever else. Channeled nose or twin nubsters on the nose would facillitate more control when backwards, as would a kicked nose rocker. That might help the rear fins stay out of the water a bit more too. It’d be wide, short and sort of straight, like a wakeboard, or skateboard. I’d love to take my small wave surfing as close to skateboarding as possible. It’s fun.
And this is coming from somebody who, I guess considers himself as part of this generation who doesn’t care what direection the board’s going. I’m 22 and been skateboarding since first grade. I can easily do fs airs, fs 360s and lipslides and such, and I’d love to easily be able to translate it to the water, especially small beach break waves.
Go Cut ! How did you decide on the dimensions or are you having a guess ?
Wildy, sure mucking around with the hull to any degree is going to have effects.
A Shortboard has a planing area of 800 sq in and even on a steep face there’s still about 400 sq in of planing area.
Hopefully if I can keep the altered area at around 2-3% it shouldn’t make too much difference.
Rohan, I cant post pics because the IOS 8 upgrade is shite but I will get some drawings together. I think the best way to go is to focus on getting a single module working and then it can be altered with different cant and toe.
guess, and i try to match the inside of the holes with the area of a thruster set up ,plus more ,to start with, that board got a lot of planning area in the tail ,i have seen that finnless design loose a lot of the vertical top to bottom surfing , it would be great not to loose that type of surfing with this design or any other, i can add little fins and make it a hybrid …by the way look what i found, this guy is a legend https://www.youtube.com/watch?v=_rGZjMk80ao&index=1&list=UUD7J3esg7INov7k2aVg0A_Q
Cut, have you got a name or a www for that guy please ? Very interesting designs !
here is him surffoils https://www.facebook.com/marcelino.junior.31?ref=ts&fref=ts, from brazil and his mentor is homero naldinho one of if not the first shaper in brazil , very cool design , the shaper of the quad inductions is stiga surfboards, did not find website , i like the simplicity of the design , i think there is a design out there that can be pushed more vertical surfing , liking your design surffoils makes sense the angles of the outside internal fins, you could make those internal fins stick a little and act like regular fins , just a my impression.
this vid is from 2010 look about 3 mins in to see the vent set up!
Thanks Cut and Foamhack, that guys got something going on with his finless / ported boards !
Here’s that pic of a foamy with the screw in side fins missing. You can see two jets on either side shooting vertically. Volume doesn’t equate to grip.
Just to backtrack with pics…
Here’s a 6’4" with an indicated water contact line leaving about 400 sq in of planing area.
What I’ve found is that a slim, longer port is better than a wide hole because it’s all about the water that interacts with the edge of the port rather than the volume of water that passes thru the port. Chanelling flow into an inefficient port doesn’t increase its effectiveness.
Internally there’s a consideration that the angle between the hull and the water rising up the wave face is around 17 degrees… So a port needs to accept a minimal internal flow angle of 17 degrees…
Actually you all probably don’t want to know the tech stuff so I might post pics with a few words.
I’ll position them in a similar arrangement to a standard thruster except that the tail ones will be on either side of the stringer rather than routing out the stringer. So I suppose it’s actually a Quad.
The effective dimension is the side length. A longer port will create a stronger effect without taking away too much planing area.
The area of the slot is similar to the area of a 3 in diameter circle.
Internally the sides are flat but angled and the back wall can’t be square because of the unwanted drag.
I’ve done this successfully a few years ago with triangular ports.