Grantmac said..
I have an RRD with slight toe out in front.

Woah...bless ya!
Made-on-Monday or after-extensive-R&D-and-rider-input

Yes
Firstly lets ascertain if everyone needs toe on every waveboard

R1DER said..

Taavi said..

Taavi said..
What an interesting and heated topic.

But my production thruster has nearly no toe-in, and it works beautifully in my real-world conditions, with stock fins.

Mentioned above that my Quatro Pyramid 77 (thruster, year 2020/21) does not have any toe in. Measured the new Pyramid 81 L now, and it has ca 1.5 degrees of toe in. Haven't sailed it yet, because of no wind and waves. Can't wait.

Probably not intentional, just a bad day for the little worker who made a bit of a mistake. I've repaired a Goya with toe out in the front. 1.5 degrees is a tiny angle an easy mistake.

Sounds more likely that the board you repaired had a problem with the boxes. On my boards (and I have had many, too many) I have never seen such an issue. I'd say it's not that difficult to measure correctly, perhaps with a precision of +- 0.1 degrees, but that's enough to give a general idea what the intention has been (to have toe in or not to have toe in).

Probably not intentional, just a bad day for the little worker who made a bit of a mistake. I've repaired a Goya with toe out in the front. 1.5 degrees is a tiny angle an easy mistake.

Many problems start when someone tries to measure boards such as fin box placement for example, especially in production boards and they are not few. This also applies to sails. If you think all comes perfect ..........

Snapfigure said..

Probably not intentional, just a bad day for the little worker who made a bit of a mistake. I've repaired a Goya with toe out in the front. 1.5 degrees is a tiny angle an easy mistake.

Many problems start when someone tries to measure boards such as fin box placement for example, especially in production boards and they are not few. This also applies to sails. If you think all comes perfect ..........

I have measured boards with a slight toe out as well. Which off course isnt good. But it probably was just 0.1 degrees, which is not really noticable compared to paralel. As long as the intention is to put the right amount of toe, which off course is always an average as the flow deflection varies depending on many factors. But if you set them at this average amount of toe, you are never far off, even if there is a 0.1 degree mistake. It is the same with everything, even basic things like sail and board size, conditions and situations always vary so often the choice may not be totally optimal but if you aim for the average, you are never far off either.

Gestalt said..

Bouke-Witchcraft said..

Snapfigure said..

Probably not intentional, just a bad day for the little worker who made a bit of a mistake. I've repaired a Goya with toe out in the front. 1.5 degrees is a tiny angle an easy mistake.

Many problems start when someone tries to measure boards such as fin box placement for example, especially in production boards and they are not few. This also applies to sails. If you think all comes perfect ..........

I have measured boards with a slight toe out as well. Which off course isnt good. But it probably was just 0.1 degrees, which is not really noticable compared to paralel. As long as the intention is to put the right amount of toe, which off course is always an average as the flow deflection varies depending on many factors. But if you set them at this average amount of toe, you are never far off, even if there is a 0.1 degree mistake. It is the same with everything, even basic things like sail and board size, conditions and situations always vary so often the choice may not be totally optimal but if you aim for the average, you are never far off either.

good to see you're finally adjusting your position. gone is, 0.1 deg toe is a game changer and water flow direction is constant which are ideas you have claimed for many years.

can I encourage you to go the full distance and accept that water flow )at the board surface) is not an average of varied flow. water flow is random, as was proven with the paper i linked way back in the beginning of this thread. that paper really proved that any talk of toe angle with respect to water flow (at the board) is not backed by science and as an extension, something else is goin on. (i also posted a video about this earlier in the thread).

You are mixing up different things. Yes, flow varies but in any case to find the best set up, you have to find the average flow, then you are never far off or as close as possible to what works best in a given situation. The flow certainly isnt random as you claim. Maybe the first mm may have turbulance but not more, as we could see by our underwater flow filming. With the tiny airbubbles in the water and watching them in slow motion, this was pretty well visible. We started off by finding the flow at an average speed, with an average weight rider without any side ways pressure on the fins. When the fins are set up ideally like this, the side fins need to be pretwisted as the flow varies over depth moving away from the centre. And from that point on, any sideways pressure, leading to an angle of attack, the change in the angle of attack is the same on all fins. Off course if all fins have the same profile and flex/twist properties. You are not going to put different tires under a race car either.

Mark _australia said..
Bouke you have done it again!
You said way back that 0.1deg changes are felt and you tweaked boards by that much and tested. You said: "A good shaper will tweak toe by 0.1 to 0.3deg"

Then today you just said 0.1 deg is not important and its ok to have a 0.1deg mistake. Well it makes a difference or it bloody doesn't.


I have said all that before, it is the size of a grain of sand in the fin box that moves the fin by 0.1deg.... it is 0.17mm toe at the end of the box!!!! (and you just ignored that then posted videos of your sponsored sailors tearing up waves as some sort of proof)

God help us all if rocker line varies by paint thickness.


(Good call, Gestalt)

You are misreading things I havent said. I havent said that 0.1 degrees can be felt. But by CFD it can be measured and since my CAD/CAM system allows me to adjust the toe by 0.1 degree, I do so. In fact, since it was made by a mathematical (theoretical) expert, I can type in the degrees to 1/100th of a degree. The CNC files are put out to the 1/1000s mm. Which is pointless of course but it is what it does and it does not bother me in any way as I dont have to calculate it, the program does it. That it is pretty accurate allows me to measure the box width and the amount of glass I want around the box so it is a tight fit with virtually no tolerance when mounting the boxes. And 0.3 degrees can sure be felt though if you have clean light wind laboratory like conditions and bigger side fins like I use. Probably not with a 8 to 11cm shark tooth fin. Which I suppose is why they use them.

Mark _australia said..
Bouke you have done it again!
You said way back that 0.1deg changes are felt and you tweaked boards by that much and tested. You said: "A good shaper will tweak toe by 0.1 to 0.3deg"

Then today you just said 0.1 deg is not important and its ok to have a 0.1deg mistake. Well it makes a difference or it bloody doesn't.


I have said all that before, it is the size of a grain of sand in the fin box that moves the fin by 0.1deg.... it is 0.17mm toe at the end of the box!!!! (and you just ignored that then posted videos of your sponsored sailors tearing up waves as some sort of proof)

God help us all if rocker line varies by paint thickness.


(Good call, Gestalt)

This is like a discussion about the existence of god. As nobody can scientifically prove that god exists, it is all just a believe thing.....
But I know when I say this, that the prophet will start again and will show his fancy colourful pictures telling everybody that there is proof...

Yeah FFS don't look for an answer in this thread....

Sheesh, I thought slalom sailors were the nerds.

Subsonic said..
Sheesh, I thought slalom sailors were the nerds.

How much toe-in are you guys using?

Mark _australia said..

How much toe-in are you guys using?

0,1 o to left side and 0,2 o to the right side and only 2 mm nose rocker for speed slalom wave board

Might be able to partially answer this in a week or 2.

A colleague built a Paulownia fish and one of the boxes is toed in a few degrees more than the other. Not sure what it will surf like.

check those angular measurements..this is how it was cast in stone on the boards of the Nile for an assymetric thruster, 4000 years ago

sheddweller said..

The red are the old RTM fins they have 1 o of toe I think and fit WC boards (2o toe in the box) . WC boards use 3o of toe in Inverted V (like Mono) or double concave boards.
The new orange SR fins have 2 degree angle to suit other non WC boards with zero to 0.8? toe-in angle in the box