Had light gusts of 8-10 knots today and got up easily, so my home made foil shim is at the right angle for my setup (0.0 degrees between fuselage and board/box), AFS Wind95 with F800 wing, Goya Bolt 135, Aerotech Freespeed 9.0 sail, and me 190 pounds with gear on.

Was nice to be able to tighten both foil box screws fully. In the past I was barely snuging up the rear screw, otherwise it would pull the mast back towards the tail about 1 degree, which really had a negative affect in light winds.

Thanks, was a little tricky making the shim with my fingers 1/2" or less from a spinning 12" miter saw blade! First shim was like 1 mm too thin, second shim I made too thick on purpose and then used 60 grit sand paper to fine tune the rake angle to 0.0 degrees. Will have to make some flat shims to see what a slight forward tilt of the foil does in light winds, maybe 0.0 is not optimal for the Bolt since with two stab shims the relatively narrow/thin tail sinks a little, but I straighten out the board by moving forward until I get up. Anything over 10 knots and it should be fine the way it is.

tonyk said..
I am not against using a shim, but I did notice that even a small shim to front or back meant that the head did not seat into tapper tight, in my case it did cause a slight side to side rock on the mast

Depending on the foil type another way would be to shim it at the fuse / mast connection point

Apart from that there are endless other options for tuning your ride

From experience is that what i think is the perfect settings today is totally different a few months later

My Foil mast is tight with shim, no movement, with mast head flange maybe 1-2 mm off the box. Can not shim fuse/mast on AFS Wind95 since the fuse/mast is one piece. Several knowledgable foilers recomended a 0.0 rake angle, and that is how I set it up before the shim by not tightening the rear screw.

Well if I seated the foil and tightened the front screw so that the flange touched the board in the front, and then tightened the rear screw it would pull the flange away from the board at the front maybe 1-2 mm. I think that is due to the play in the coarse threads and the fact that the rear screw has more leverage due to the barrel nut being deeper in the head. I also think the side walls of the box have some flex, and make contact before the head is fully seated. Bottom line is the foil head is tight and at the right angle. I think you are stuck on thinking of a DT box as a box for fins, this is a foil ready DT box and Goya made it strong for fins AND foils! It really should just be called a foil box that also accepts DT fins.

segler said..
You wrote: "Well if I seated the foil and tightened the front screw so that the flange touched the board in the front, and then tightened the rear screw it would pull the flange away from the board at the front maybe 1-2 mm."

This is exactly what happens when the top of the foil is "bottoming out" on the inside top surface of the finbox. That contact is preventing the front and back rounded tapers from completely seating. One or the other, but never both at the same time. The finbox is not deep enough.

The solution is either a different board, or you could trim the top of the fitting a little, making sure that you maintain good edge margin for the screw nuts. It would not take much since you are only 1-2mm too tall. Don't use a saw. Just grind it.

For the record I am not replying to your posts on this topic anymore.

So for everyone reading this topic, I will get back with an update on the use of the shim in the Goya foil box after more sessions. Now I did check the inside of the foil box, and deck above it, with a 3-1/4" diameter illuminated magnifing glass after my first session using the shim, there were no cracks or deformed surfaces.

With the current crop of greatly reinforced DT boxes in "foil ready" boards, all of my fears may be moot. I certainly hope so. Go forth and foil.

You will never catch me introducing point loads with shims or top fill-ins. Not worth the risk for a USD $2500 foil or a USD $2200 board.

A leash is cheap insurance. MFC makes leash bases, but I use zip-tie bases and replace the foam tape with the 3M gray stuff that MFC, and others, use. Zip tie bases and 3M tape at any auto parts store. A meter of coated kite line between the leash base and a rear footstrap (oh horrors, a windfoiler using kite stuff).

Maybe this is a better method for adjusting foil/board angle?
No fin box point loading problems introduced here.

Yes, I used the Seatex method to make my boxes.
Careful with the weight, my first version weighed 697gr.!!
Couldn't use that one, so mk2 was 564gr.
I've just done the latest at 400gr.
Part of the reason that Foil boards tend to be heavy.
My usual slapper finbox weighs 178gr.
I've weighed several foilboards and there aren't many under 10kg, ready to go.

Te Hau said..
Yes, I used the Seatex method to make my boxes.
Careful with the weight, my first version weighed 697gr.!!
Couldn't use that one, so mk2 was 564gr.
I've just done the latest at 400gr.
Part of the reason that Foil boards tend to be heavy.
My usual slapper finbox weighs 178gr.
I've weighed several foilboards and there aren't many under 10kg, ready to go.

Goya Bolt 135 is under 7.6 kg, can hold it with one hand by the top rail.

I think most boards have proper box angles so that the foil will start to fly when the board speed is enough.

Look at what happens when an airplane takes off. It rolls down the runway coming up to speed. When it has reached the correct speed, you notice that it rotates up before it actually lifts off the deck. The pilot (or computer) has to do this intentionally or the plane will never fly. The rotation adds angle of attack to generate lift.

Same for our foils. If the combination of finbox and foil have the correct angle relative to the bottom of the board, it will have enough angle of attack to come up into flight by itself when the board speed is enough. We don't have to "rotate" to take off. We hope so anyway. Actually we can rotate. I do it all the time, but it is not necessary.

So, if the foil points down relative to the bottom deck of the board, you have to really back-foot it to get it to lift.

If the foil points up relative to the bottom of the deck of the board, you have to keep your weight forward to control the lift that happens all by itself.

Again, I believe most boards and foils have already figured this out. Since board manufacturers install deep tuttle boxes generally to the design spec of tuttle, the foil manufacturers have also molded their deep tuttle tops at the correct range of angles for doable control of angle of attack and flight. Same for the flat dual-track tops.

By the way, all this presumes that you already have the front wing balanced at or near the midpoint between your feet.

Sandman1221 said..

Paducah said..

Sandman1221 said..

Te Hau said..

Maybe this is a better method for adjusting foil/board angle?
No fin box point loading problems introduced here.

The AFS Wind95 foil mast and fuselage are one piece, so can not shim the mast/fuselage junction.

In order to have a 0.0 degree foil rake angle I had to leave the rear screw just snug (not tight), with the shim I make it tight, I am a lot more comfortable with that. The new generation of foil ready boxes are constructed much stronger all around (including the box top and the board deck) than a normal DT box, just look at the seatex video on how they make a foil box.

Wait? Zero degrees fuse/board angle? If that's what you meant, you want more like 2.5-3 degrees - ie the board should be angled up from the foil (think nose high). AFS got the angle right when they molded their flange. No need to shim a different angle unless something strange is going on. If I misunderstood you, sorry.

Thanks for getting back about the rake angle, posted in another topic but no one responded. So using a buble level app on my phone the rake angle for AFS Wind95 foil with the flange seated was 0.0 degrees, so I made the shim to get that same rake angle. Now an issue for me is the Goya Bolt 135 board, because it has a relatively narrow/thin tail compared to a foil board the tail sinks especially with 1 or 2 stab shims in light winds, so what I do is move forward on the board to level it out until I get up, that works great just have to be careful moving back into the front foot strap. So is it really at 0.0, according to buble level app it is, now my local shop owner Britt at North Beach Windsurfing and Pascal at Goya both said it should be at 0.0 degrees. I saw in one video for Phantom foils it should be like you said, at least 2.5, but maybe that is for a foil board?

Are you measuring the wing vs the bottom of the board? or something else?

In theory, and what I thought many years ago, it shouldn't matter a few degrees here or there because the board is in the air, right? Actually, it helps in a couple of ways. It helps when taking off especially those of us who take off before the board is actually planing. In that case, the tail is sunk a bit and you run the risk of the foil having too high of an angle of attack to take off efficiently.

Another important point where it matters is when you touch down, especially at speed. If there is a postive 2-3 degree angle, then the board touches flat run of the tail first and skips back up a bit easier. If it's flat or even nose down, then the nose or front part of the rocker is likely to hit first and slow you down more.

marseille.glissattitude.com/blog/reglages-windfoil-le-rake.html (Google translate or Chrome/Chromium is your friend if you don't read French like me)

I think it's been mentioned here by those closer to the pointy end that course racers tend to favor shallower angles and slalom greater ones (say 1.5-2 vs 2.5-3)

There is also the issue of it moving the CoL forward/back which I'm not sensitive enough to notice. ymmv

Having said that, I've never measured/tweaked my AFS and we get along just fine.

WillyWind said..

Sandman1221 said..

Paducah said..

Sandman1221 said..

Te Hau said..

Maybe this is a better method for adjusting foil/board angle?
No fin box point loading problems introduced here.

The AFS Wind95 foil mast and fuselage are one piece, so can not shim the mast/fuselage junction.

In order to have a 0.0 degree foil rake angle I had to leave the rear screw just snug (not tight), with the shim I make it tight, I am a lot more comfortable with that. The new generation of foil ready boxes are constructed much stronger all around (including the box top and the board deck) than a normal DT box, just look at the seatex video on how they make a foil box.

Wait? Zero degrees fuse/board angle? If that's what you meant, you want more like 2.5-3 degrees - ie the board should be angled up from the foil (think nose high). AFS got the angle right when they molded their flange. No need to shim a different angle unless something strange is going on. If I misunderstood you, sorry.

Thanks for getting back about the rake angle, posted in another topic but no one responded. So using a buble level app on my phone the rake angle for AFS Wind95 foil with the flange seated was 0.0 degrees, so I made the shim to get that same rake angle. Now an issue for me is the Goya Bolt 135 board, because it has a relatively narrow/thin tail compared to a foil board the tail sinks especially with 1 or 2 stab shims in light winds, so what I do is move forward on the board to level it out until I get up, that works great just have to be careful moving back into the front foot strap. So is it really at 0.0, according to buble level app it is, now my local shop owner Britt at North Beach Windsurfing and Pascal at Goya both said it should be at 0.0 degrees. I saw in one video for Phantom foils it should be like you said, at least 2.5, but maybe that is for a foil board?

What are you measuring that gives you the 0.0 degree reading? Is it the bottom of the fuselage? in my starboard foil, I was told to measure the angles right behind the front wing, with the board upside down (of course). In that position, the ideal angle is between 1.5 and 2 degrees compared to the bottom of the board. But I am measuring the top of the fuselage in comparison to the bottom of the board. I am not sure what the actual rake of the foil is.
i wonder if different companies use different ways to measure the angle at which the foilS should sit. My guess is yes.

What I meant in the last paragraph is that companies might use different way to instruct us on how to measure The angle of their foils.

WillyWind said..

Sandman1221 said..

Paducah said..

Sandman1221 said..

Te Hau said..

Maybe this is a better method for adjusting foil/board angle?
No fin box point loading problems introduced here.

The AFS Wind95 foil mast and fuselage are one piece, so can not shim the mast/fuselage junction.

In order to have a 0.0 degree foil rake angle I had to leave the rear screw just snug (not tight), with the shim I make it tight, I am a lot more comfortable with that. The new generation of foil ready boxes are constructed much stronger all around (including the box top and the board deck) than a normal DT box, just look at the seatex video on how they make a foil box.

Wait? Zero degrees fuse/board angle? If that's what you meant, you want more like 2.5-3 degrees - ie the board should be angled up from the foil (think nose high). AFS got the angle right when they molded their flange. No need to shim a different angle unless something strange is going on. If I misunderstood you, sorry.

Thanks for getting back about the rake angle, posted in another topic but no one responded. So using a buble level app on my phone the rake angle for AFS Wind95 foil with the flange seated was 0.0 degrees, so I made the shim to get that same rake angle. Now an issue for me is the Goya Bolt 135 board, because it has a relatively narrow/thin tail compared to a foil board the tail sinks especially with 1 or 2 stab shims in light winds, so what I do is move forward on the board to level it out until I get up, that works great just have to be careful moving back into the front foot strap. So is it really at 0.0, according to buble level app it is, now my local shop owner Britt at North Beach Windsurfing and Pascal at Goya both said it should be at 0.0 degrees. I saw in one video for Phantom foils it should be like you said, at least 2.5, but maybe that is for a foil board?

What are you measuring that gives you the 0.0 degree reading? Is it the bottom of the fuselage? in my starboard foil, I was told to measure the angles right behind the front wing, with the board upside down (of course). In that position, the ideal angle is between 1.5 and 2 degrees compared to the bottom of the board. But I am measuring the top of the fuselage in comparison to the bottom of the board. I am not sure what the actual rake of the foil is.
i wonder if different companies use different ways to measure the angle at which the foilS should sit. My guess is yes.

I measured at the bottom of the fuselage right behind the wing and the bottom of the board next to the foil mast flange.

never mind, could not delete post so wrote this.

segler said..
That's right. Once you are in the air, it doesn't much matter. When you are still on the water, it can matter. You need to get the angle of attack for flight. The board should help with this, not hinder it. I think the angle of difference between fuselage and board bottom will be what you can measure. Yes, of course, some fuselages are tapered and such, but you get the idea.

If things are just right, the foil is already applying uplift even at subplaning speeds. This makes it really easy to get the board planing before rising into flight. You don't even have to haul it up there. This is important for formula boards with their massive nose rocker. Just sheet in or pump to get the board planing, then quietly add a touch of back foot or back sail rake to rotate for takeoff.

Agree, always read about guys pumping to get up in light winds, but I do not, just focus on getting the board planing and then either sheet in a little or pop the tail with my back foot and I am in the air.