Forums > Windsurfing Foiling

Foil Mast angle

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Created by BSN101 > 9 months ago, 8 Oct 2021
SA_AL
304 posts
24 May 2022 10:49AM
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SA_AL said..
I recently got IQ foil SB 95 cm mast and try to fit into FMX foil race board. IQ foil has a cutting guide line but even after aeroegnr said..



Also, you guys having the bolts loosening up: are you using tefgel? It helps....


I have been using tefgel only for the fuselage connection to the mast not for the mast going to the DT box. I will try that!

Grantmac
2317 posts
24 May 2022 12:26PM
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segler said..
Wrong, Grant. ONe of my foils is a Moses Race 105-900 which I mount into a Roberts GT 32 foilboard. The board has a regular DT box without a roof, and the foil is non flanged. So, I rock. I really don't like loose screws, either on the board or in my head.



That's only an 81cm wide board and from what I recall you had the straps moved forward because you couldn't get small sails to work on it.

That's hardly a course racing setup using a 9m in +25kts. Don't need shims for just putting around.

WillyWind
579 posts
24 May 2022 1:13PM
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Sandman1221 said..
Well all I can say about rocking a carbon mast head back and forth in any box, and tightening the screws and repeatedly rocking and tightening, is please send me a good photo of the inside of your box, because I would not be surprised to see cracks in the box tapers and walls! Carbon masts (sail or foil) certainly can flex, but "I do not think" the tapers and side walls of a DT box (carbon or glass) were designed to flex and the rocking and tightening routine described by some would certainly flex the box and could crack it.


That is how starboard recommends to set the mast into the box. There is a long video where Gonzalo Costa Hoevel shows how to do it but I cannot find it. I'll post it if I find it.

FormuIa
105 posts
24 May 2022 5:31PM
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Here's how Starboard recommends it:
Starboard IQ mast into the IQ board, rocking it back and forth, etc.



Starboard recommendations for setting the mast rake


They've got the videos published on their foil assembly website (but are unlisted on YT, hence hard to find):
iqfoil.star-board.com/guides/

Not that current SB recommendations are 1.7-2 degrees of mast rake for racing (VMG) and close to 3 degrees for slalom. This info is from Remi Villa.

Why don't companies move to a flat ceiling foilbox on race boards, instead of having an angled ceiling? Wouldn't this allow easier shimming and offer better cross-brand compatibility without having to cut the mast? Like with the IQ mast and IQ board, you know it's going to fit okay, because both the mast DT head and the foilbox are straight.

Subsonic
WA, 3354 posts
24 May 2022 7:37PM
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Sandman1221 said..
Well all I can say about rocking a carbon mast head back and forth in any box, and tightening the screws and repeatedly rocking and tightening, is please send me a good photo of the inside of your box, because I would not be surprised to see cracks in the box tapers and walls! Carbon masts (sail or foil) certainly can flex, but "I do not think" the tapers and side walls of a DT box (carbon or glass) were designed to flex and the rocking and tightening routine described by some would certainly flex the box and could crack it.




its not a violent rock back and forth.

Using/relying on tensioning the bolts to tow the head of the foil into the box can lead to snapped bolts, and bolts loosening whilst foiling which can gain you the same result. trust me, i've been there and done that.

if the foil head damages the wall/tapers of the box, then there is something else wrong. Rocking the foil in back and forth won't do that damage.


Im interested to hear what technique you think people are using when seating the foil properly, that you think they are going to damage the foil box? You do go off on some strange tangents sometimes.

Sandman1221
2776 posts
24 May 2022 10:28PM
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subsonic

Im interested to hear what technique you think people are using when seating the foil properly, that you think they are going to damage the foil box? You do go off on some strange tangents sometimes.




Well first it is not necessary to rock foil back and forth, while tightening first the front screw and then the rear screw, and repeating that several times or more, if you use a shim! Just seems a lot of work to do that since after every rock of the foil, you have to turn board on its side to tighten one screw then return board to upside down position to rock foil again in opposite direction, and on and on for what 5 times according to one person!

With a shim, I just insert foil, turn board on its side and tighten front screw and then back screw and I am done!!, no loose screws even after several hours on the water foiling.

So where is the strange tangent, first paragraph or second paragraph?

Sandman1221
2776 posts
24 May 2022 10:32PM
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FormuIa said..
Why don't companies move to a flat ceiling foilbox on race boards, instead of having an angled ceiling? Wouldn't this allow easier shimming and offer better cross-brand compatibility without having to cut the mast? Like with the IQ mast and IQ board, you know it's going to fit okay, because both the mast DT head and the foilbox are straight.



My 2018/2019 model year Goya Bolt Pro 135 L board came with an impact-proof foil ready DT box that has a flat top, My 2019 AFS foil came with a DT mast head (so angled), and AFS is still making them that way!, I guess for capability with standard DT boxes?

segler
WA, 1656 posts
24 May 2022 10:48PM
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The rocking that Gonzalo shows in the first video is what Sailworks does as well. It's what I see all the time on the beach in Hood River for those foils without a flange. When you buy a foil from Sailworks they demonstrate the assembly into the board this way. When I bought my AFS-2 (non-flanged) foil from them in 2017, I kept getting loose screws after being on the water. They said to simply rock it more and tighten it more. That solved the problem. I never have loose screws now, and have never broken a screw. Also my boxes don't have any cracks in the tapers, and the boards do not take on water. I use one of those tiny illuminated probe cameras with a cell phone to inspect inside the box. Use McLube to help with the friction. Preloaded screws that do not move will perform better than loose screws that get pulsed.

You notice that Gonzalo's board has those screw chimneys. That means that there is an inside roof in the box.

In the second video the use of the "spacers" to set the rake obviously means that the top of the foil is pushed up tight against the inside roof. Good example of brand matching.

That little ole finbox is carrying the entire 250 pounds of rider, board, and rig. Always and forever, this stuff is intended to prevent failures.

Sandman1221
2776 posts
24 May 2022 11:01PM
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segler said..
The rocking that Gonzalo shows in the first video is what Sailworks does as well. It's what I see all the time on the beach in Hood River for those foils without a flange. When you buy a foil from Sailworks they demonstrate the assembly into the board this way. When I bought my AFS-2 (non-flanged) foil from them in 2017, I kept getting loose screws after being on the water. They said to simply rock it more and tighten it more. That solved the problem. I never have loose screws now, and have never broken a screw. Also my boxes don't have any cracks in the tapers, and the boards do not take on water. I use one of those tiny illuminated probe cameras with a cell phone to inspect inside the box. Use McLube to help with the friction. Preloaded screws that do not move will perform better than loose screws that get pulsed.

You notice that Gonzalo's board has those screw chimneys. That means that there is an inside roof in the box.

In the second video the use of the "spacers" to set the rake obviously means that the top of the foil is pushed up tight against the inside roof. Good example of brand matching.

That little ole finbox is carrying the entire 250 pounds of rider, board, and rig. Always and forever, this stuff is intended to prevent failures.




Point is you can avoid the time consuming task of fitting the foil your way, Sailworks way, if you use a shim! Just because everyone is doing it at Hood River does not mean it is the best way. There are lots of examples from history about everyone doing something the wrong way, but not realizing it, because they were trained that way.

You are checking the box to make sure it is not cracked because that is a potential problem with the way you mount the foil, I do not need to worry about it.

RuddeBos
136 posts
24 May 2022 11:25PM
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Rumours from the IqFoil Europeans
Some sailors were fixing in their masts into their boards so tightly, that the barrel nuts were pulling through the head of the Tuttle box.
Used sacrificial bolts to pull the foil mast in, then replaced with new bolts for the racing .
Sebastian Kordel may have lost his chosen race foil, when the bolts / barrel nuts failed.

to get the racing edge, it's all about getting the right mast angle angle and setting it so it doesn't move.

FormuIa
105 posts
24 May 2022 11:34PM
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Speaking of that... Innovation Quality :)





Sandman1221
2776 posts
24 May 2022 11:45PM
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FormuIa said..
Speaking of that... Innovation Quality :)






Front screw hole, back screw hole, or both like that? I use a metal washer on top of a hard plastic washer to spread out the load and provide some shock absorption.




FormuIa
105 posts
25 May 2022 12:21AM
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This was the back screw. Front one was okay. Not my board though, found a photo online.

I also use large A4 316 stainless steel washers to distribute the loads, both on front and rear screws. Have also upgraded them to TX30, which can be tightened more easily and don't strip as quickly as PH3 ones.

FormuIa
105 posts
25 May 2022 12:25AM
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Sandman1221 said..
My 2019 AFS foil came with a DT mast head (so angled), and AFS is still making them that way!, I guess for capability with standard DT boxes?


No idea really. You can't put a square head mast into a sloped DT foil box, but you can do it the other way around.

It's just the shimming is more complicated in this case, but since the DT angles are known from the drawing, it's not exactly aviation science to create a triangular shim to fill the space between the (sloped) mast and flat foilbox.

WillyWind
579 posts
25 May 2022 1:35AM
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Sandman1221 said..

Point is you can avoid the time consuming task of fitting the foil your way, Sailworks way, if you use a shim! Just because everyone is doing it at Hood River does not mean it is the best way. There are lots of examples from history about everyone doing something the wrong way, but not realizing it, because they were trained that way.

You are checking the box to make sure it is not cracked because that is a potential problem with the way you mount the foil, I do not need to worry about it.


even with shims some masts require rocking because of the relatively tight fit. Rocking is better than tighten the screws to pull the mast in. Notice that starboard recommends rocking to set the mast and they also use shims.

aeroegnr
1731 posts
25 May 2022 1:50AM
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FormuIa said..
This was the back screw. Front one was okay. Not my board though, found a photo online.

I also use large A4 316 stainless steel washers to distribute the loads, both on front and rear screws. Have also upgraded them to TX30, which can be tightened more easily and don't strip as quickly as PH3 ones.


There's an additonal full screw tunnel sized washer, about 1/4", oval shaped for my back screw that the serrated washer fits over. They started handing these out to the new boards last year. Was it an older setup before they did that?

FormuIa
105 posts
25 May 2022 1:55AM
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Possibly it was an older setup, yes. I'm using large washers 20-25 mm in diameter, because the holes in my foilbox are circular.

Sandman1221
2776 posts
25 May 2022 2:53AM
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WillyWind said..


Sandman1221 said..

Point is you can avoid the time consuming task of fitting the foil your way, Sailworks way, if you use a shim! Just because everyone is doing it at Hood River does not mean it is the best way. There are lots of examples from history about everyone doing something the wrong way, but not realizing it, because they were trained that way.

You are checking the box to make sure it is not cracked because that is a potential problem with the way you mount the foil, I do not need to worry about it.




even with shims some masts require rocking because of the relatively tight fit. Rocking is better than tighten the screws to pull the mast in. Notice that starboard recommends rocking to set the mast and they also use shims.



Sailsworks warned me that using the screw to pull the foil mast head into the box would result in stripping out of the barrel nut in the AFS mast head. When my foil was new had to rock the foil back and forth a little to get all the way in, but never did the alternate screw tightening routine. And now with the shim I can just rock the foil a little with one hand when board is on its side to get mast head all the way in, <1/4" at the front has to get settled in the box using one hand to pull/rock mast towards the front. Once front is in, back is in too, so no rocking for back screw.

Subsonic
WA, 3354 posts
25 May 2022 5:29PM
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Sandman1221 said..

subsonic

Im interested to hear what technique you think people are using when seating the foil properly, that you think they are going to damage the foil box? You do go off on some strange tangents sometimes.





Well first it is not necessary to rock foil back and forth, while tightening first the front screw and then the rear screw, and repeating that several times or more, if you use a shim! Just seems a lot of work to do that since after every rock of the foil, you have to turn board on its side to tighten one screw then return board to upside down position to rock foil again in opposite direction, and on and on for what 5 times according to one person!

With a shim, I just insert foil, turn board on its side and tighten front screw and then back screw and I am done!!, no loose screws even after several hours on the water foiling.

So where is the strange tangent, first paragraph or second paragraph?


Depends what you mean by necessary. Not all shims close the space up before everything is locked in. I used to use a shim very similar to yours on my f4 set. Still rocked the foil mast in to make sure it was completely seated, and to prevent wear and rear on the threads of barrel nuts, and not strain the bolts which i later rely on to keep the foil from detaching. I've seen more than one bolt snap whilst being tensioned up. Imagine stretching a bolt right before you reach the point where its locked up. Then go out foiling on it.
think of those bolts as retainers, not as tensioners.

FormuIa
105 posts
25 May 2022 7:38PM
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That's a great thing with otherwise crappy Philips footstrap screws, the heads will get round long before the bolt will snap :) With TX30 for foils, this normally doesn't happen and something else will break first.

Gwarn
245 posts
25 May 2022 9:12PM
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Bolts are easy

Sandman1221
2776 posts
25 May 2022 9:38PM
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Gwarn said..



Bolts are easy




"Bolts are easy" to over tighten! Philips head was designed to prevent over tightening, since it will cam out when tightened enough. Though the SS PH3 screw driver I have has serrations on the tip that help to keep tip from camming out easily.



Subsonic
WA, 3354 posts
25 May 2022 10:11PM
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Sandman1221 said..

Gwarn said..



Bolts are easy




Bolts are easy to over tighten! Philips head was designed to prevent over tightening, since it will cam out when tightened enough. Though the SS PH3 screw driver I have has serrations on the tip that help to keep tip from camming out easily.


Not if you use a spinner handle. Not sure if that's what they call them where you are, but essentially a screwdriver handle, with the right size socket on it. no slipping out and destroying the head and screw driver, but no over torquing either.

Gwarn
245 posts
25 May 2022 10:34PM
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Ya I use a 1/4 drive spinner.
This is not a problem for me.

WillyWind
579 posts
15 Jun 2022 7:44AM
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Paducah said..



I am not trying to revive the discussion about whether the mast head should sit on the roof of the box or the tapers (if you are interested about it, read-reread the prior four pages). I only want to know: for those using shims, especially the thick ones, the front taper might not even contact the front of the mast head, right?

FormuIa
105 posts
15 Jun 2022 8:26AM
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Possibly it's without full contact, yes. If I shim it to 2? or more, it will be about 3 mm outside of the box at the front end, but there is full contact with the DT foilbox "ceiling" with a proper (custom) shim. Also the bolts stay tight even after a couple of hours (and there's no creaking or other sounds going into the jibe).

Sandman1221
2776 posts
15 Jun 2022 8:46AM
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WillyWind said..

Paducah said..




I am not trying to revive the discussion about whether the mast head should sit on the roof of the box or the tapers (if you are interested about it, read-reread the prior four pages). I only want to know: for those using shims, especially the thick ones, the front taper might not even contact the front of the mast head, right?


With those shims on the far left for sure, but the shim I made sets foil fuselage at 0.0 degrees and so the foil mast head contacts the front and rear tapers while the top of the mast head is seated up against the inside top of foil box.

SA_AL
304 posts
19 Sep 2022 4:20AM
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Paducah said..
It's the "wing" angle - angle of attack (AoA) that matters. Fortunately most manufacturers design their fuses to be inline with their fuses so we usually just measure flat part of the fuse compared to the board bottom instead. You can use a cheap digitial level or a cell phone app. Almost all manufacturers bake in an angle from 1.5-2.5 degrees. That is the board points that much higher than the fuse

There have been extensive threads on here. Search for "mast rake". It does make a bit of a difference in things like take-off, touch downs and rotating the rider more or less forward over the wing and you definitely don't want 0 degrees but, again, this is ultimately determining wing angle not just the mast itself.

As thedoor suggests, getting the mast properly seated in and even will get you most of the way there. More experienced riders and especially racers are more sensitive to mast rake which is why shims that sit on top of the mast head are available to fine tune the angle.


I am not sure what is required for early flights: is it the mast rake or back wing shim provides effective earlier flight. Many of the racers seems to be using 3.4 degrees in their set-up but I feel more comfortable with 2.2 on my SB IQ foil. I am thinking mast rake is better for flying easier with touch downs but back wing shims (i.e. +1) may provide better lifts for foiling-up. Could someone comment on these factors?

FormuIa
105 posts
19 Sep 2022 5:47AM
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Racers don't use +1 because it's too slow (quoting a pro racer I spoke with).

Mast rake puzzles me, Phantom recommends more rake for stronger winds and VMG sailing, while Starboard recommends LESS rake for stronger winds. My take is you'll fly earlier with less rake (eg. 1.5 degrees), but more rake (2-3 degrees) offers softer touchdowns, though this also means more lift from the (stronger) wind.

Rolz
QLD, 169 posts
4 Mar 2023 4:38PM
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hello all, been learning all about mast rake to improve my faster foil sailing... I don't race or anything I just want to learn to foil faster...
for me at this stage the rake of my mast sweet spot is about 3.5deg.

I'm waiting for my electronic level to arrive to be 100% certain, I'm not overly happy with my mobile app because the buttons or the raised part for the cameras might be added in consistencies when I calibrate on the board and then balance on the foil.

I had tried F4 supplied spacers, but found the 3d print density to low and they were being squashed, I printed my own at 100% density and now I minimal squashing of the spacer... and now more consistent start mast angle and finish session mast angle.



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"Foil Mast angle" started by BSN101