Boards for eFoil


#21

as its my day job If I can be of help in creating a cad file on shape 3d and the g code for people to cut it on there cnc for personal use I have a full licence for shape3d which is a board shaping software I’m happy to do draw up a basic design and file that people can down load.

bellow is just a example of what I normally cut


#22

That is very nice! I have a question. How do you line up the blank when you flip it over to machine the other side?


#23

I have a center line machined down the table and then just a line on each end of the blank.


#24

What are the consequences of using a larger board? I have an old windsurfer I am considering using. I assume greater stability but also greater drag until airborne. Or perhaps there is less drag because of increased buoyancy? Increased weight. Anything else?


#25

I wonder myself. Since foiling is a physical challenge on its own, I want to make it easy to learn.


#26

probably the biggest thing is swing weigh, having a smaller lighter board means it is easier and faster to react, the odious benefits of less to have to lift. Having a bit of width will also hep a lot when you make a unscheduled landing and offer a bit of stability when taking off or going at sub foiling speeds.


#27

Another factor in the volume consideration is if you have to paddle back to shore in the event of no power.


#28

This is such a great place for the DIY. My project started from scratch in August with building my board.My idea was to create a hollow medium sized wooden surfboard. First goal was to float👍.

As you can see, my mast was pretty amateur and the foil the same. I’m currently reworking the mast- I will post when I have it updated.

I was pretty happy with outcome of the board- sealed it with teak oil and then marine spar urethane. I tried the board/ foil in early September as a tow behind the boat before the boat was put away for the summer. I believe the mast was my downfall - I could stand up on the board but no matter how how far back I was on the board, it would nose dive with slight increase in speed. I believe I had too much drag on the mast. I’m also improving the foil now that I’m finding more information out there to go on. I have a video on the water- just can’t upload.


#29

@Dave, Hopeing this will help, if it does, see more videos on youtube from Delta Hydrofoil Pro Tip. :smile:


Good work tho…


#30

So the guy in the video confirms my theory in the „lets make the optimum wing first” thread. In the first 2min he explains how the kite creates a large moment. We don’t have that moment with the motor pushing close to the wing. So we probably all should modify our back wing for less downforce.


#31

Oh definitely helps - thanks for the response and video link.


#33

Hi just thought i would start to post after following this site for a while. Below is a pic of a board and foil , the board is am old SUP with high density foam layed in for the mount and it’s my second wing the first failed in the fuselage, we live and learn.


#34

today i‘ve planned an cut out a prototyp in the size of 30% from the original. the final one has a size of 160cm65cm13cm, so i think i have enough volume.


#35

I completed the first of at least 4 lamination cycles. The bottom is far from smooth, but should be very strong. My vacuum bag ripped, so I couldn’t apply enough pressure to keep it flat. It will probably remain uneven. Hopefully the top will be smoother!


#36

Progress on the board so far. Now ready for glassing. Going to use 2 layers 6oz glass top and bottom with an extra 6oz patch where the foil goes. Didn’t have a hot wire cutter so I had to block sand the entire bank.


#37

Looks very nice. Sanding it by hand must have been messy. Here is what I learned from the glassing job:

  • I probably mixed 20 batches of epoxy in total. A coat hanger wire can be bend into an L-Shape to use it as a mixer in a cordless drill. Well worth it.
  • I used 35 pairs of gloves.
  • Put your scale in a plastic bag.
  • Taking your time to cover all surfaces with plastic is worth it.
  • Any air bubbles underneath the glass will become holes during sanding.
  • Bags filled with water help pressing the glass into the electronics cavity.

#38

thanks for sharing @maxmaker. @goldy nice job!


#39

Thanks Max. Yea it was really messy, not the best way to do it. Great, thanks for the tips, I will use the plastic bag filled with water for the electronics cavity, was thinking about what to do to press the sides in. Cheers


#40

I vacuum the compartment by itself and then the board


#41

Not the best way to mix epoxy with a drill (high speed) unless you use a degass chamber on the epoxy, it creates load of bubbles. Slow with a “paddle” will give lot less bubbles.

Vacuumnagging is not that hard, and will give really good results compared to hand layup, especially in corners and other complex geometries. Your fiberglass/epoxy will be lighter and “stronger”(higher tensile strength) as well, due to a better ratio of resin and cloth, the fact that almost all air is removed and the cloth sticking well to the foam below.