Forum Wingfoil - Pimpyourride.fr

[Saamgil]

Est ce que quelqu'un a déjà testé ou entendu parler des mats project cedrus (https://projectcedrus.com/)?
Ils proposent un mat carbone avec des adaptateurs pour la pluspart des fuselages du marché. Ça peut permettre une upgrade de son foil en passant au mat carbone.

[ho-okipa]

Le mat en lui-même a l'air sympa, mais je me pose la question sur les jonctions car le fait d'avoir des adaptateurs ne doit pas aider à la rigidité. Mais je suis aussi curieux des retours.

[Saamgil]

surtout la jonction avec la platine qui a l'air petite. Pour ce qui est de la jonction avec le fuselage beaucoup de marque le font, tant que l'emboitement dans le fuselage est bon ca doit rester rigide.

[Project_Cedrus]

Bonjour, ca fait tres long temps que j'ai parle francais, et je suis desole pour l'ecrit:) Je t'assure que le mast Project Cedrus et le plus rigide du l'industrie. Il y a beacoup de reaction ici: https://projectcedrus.com/feedback/ et si tu comprend l'englais tu peux voir la critique de Gunnar ici:

Merci pour les questions, je suis pas ici a vendee les masts mais just pour dis bonjour parceque cet site et forum est tres chic!

Kyle @ Project Cedrus

[Saamgil]

My english is not perfect neither. I'am just wondering with the connection betwin the mast and the mounting plate. All the masts I have seen goes inside the plate, here it's juste flat to flat, is it enough to avoid movments?

[Project_Cedrus]

Here is how Project Cedrus connects to the plate mount. The two M8x1.25 screws provide more than enough force to prevent any movement. It is a very stiff connection.

[ho-okipa]

What surprises us is that this is a rather unusual type of connection in mechanics. The embossing is too short to participate in the stiffness (1), so the lateral stifness (red torque - 2) is given by the tensile work of the stainless screws (which are not the stiffest ones). I think that a lot of work has been done on the stiffness of the mast itself and seems to have been completed, it is a pity to lose some in the connection. A longer interlocking (3) would be better but more difficult to achieve because it requires tight adjustments and therefore good manufacturing accuracy, and a larger raw as the part seems machined.
Again, this is just a theoretical observation based on the design, not having tested it.

[Hadou]

Bonjour, ca fait tres long temps que j'ai parle francais, et je suis desole pour l'ecrit:) Je t'assure que le mast Project Cedrus et le plus rigide du l'industrie. Il y a beacoup de reaction ici: https://projectcedrus.com/feedback/ et si tu comprend l'englais tu peux voir la critique de Gunnar ici

Merci pour les questions, je suis pas ici a vendee les masts mais just pour dis bonjour parceque cet site et forum est tres chic!

Kyle @ Project Cedrus

Hi Kyle,

Really Happy to have you on the forum !
I 've been following your project with curiosity and saw Gunnar's video already.
I've been in touch with some brands like Takuma of Takoon who are currently working on carbon masts prototype.It would be interesting to see how the carbon cedrus project works with these foils...
I guess it's difficult to adjust things when you see the rake of some foils like the 2021 Kujira which is really angled forward (3 degrees). Curious to see how you can adjust this connection to the fuselage.

feel free to share any news about your project here. you 'll quickly see that lot of guys here are into "tuning" and Diy

[Project_Cedrus]

@ho-okipa I appreciate your theoretical observations. At this point I have 4 years of data on Project Cedrus, and trust the real world testing experience. I have also designed wings for Boeing and many products for Apple, so I can assure you a lot of engineering and design time has gone into this. Every single one of my 100+ customers has commented on the increased stiffness of the mast when compared to any carbon mast (Axis, Lift, Moses) and aluminum.

Yes, Project Cedrus is a different connection that other masts. I do not have a traditional collar at this time, because it is not good to impart bearing stress into carbon fiber. And as you point you, it does require tighter tolerances and will add weight and cost. Stainless steel is very stiff (200GPa) vs. Aluminum (68GPa) vs. intermediate carbon fiber (140GPa) so I'm not sure what you mean by "not the stiffest." Bolted joints are excellent for this application, as they give predictable strength and have a much more ductile failure mode than composites in bending. I have a lot of analysis on these materials and joint design on my blog:
https://projectcedrus.com/general/solid ... sites-101/
https://projectcedrus.com/general/new-w ... ard-mount/

That being said, stainless screws do have a tensile limit, and even though the joint is very stiff, there are some windsurfers and jumping wing foilers who have exceeded the STRENGTH of the joint and bent the screws. For this reason I introduced the new mount and screws, and may introduce a new mast design with a more traditional collar which does not bear into the carbon. So in closing your comments are valid, however I assure you that the mast and setup is extremely stiff. If anything, the strength limits are being pushed which would be the only reason to explore a collar. Under normal riding conditions, the collar is not providing support to the mast. Only under extreme hiked-out windsurfing or jumping will the collar contact, and remove load from the screws. For 99% of riders, this joint has adequate strength as well.

[ho-okipa]

Hi Kyle, I am impressed by the quality of your explanations on your links… As you say, we must be wary of forums and for the moment I answered too quickly on a theoretical aspect without pushing the investigation to the end. I saw the work on the screws and the connection. I agree 100% that for the majority of users it is enough, but it is the fault of engineers to always want to improve , sometimes forgetting that there is a price in front and that if your solution brings a sufficient stiffness, it also allows to have a controlled cost.
So after having read more in detail, I am only more curious and hope that Hadou will have the opportunity to test them and convert us
I really like the concept to have a compatible mast for all kinds of wings, just by changing the adapter...

[Project_Cedrus]

Yes, I have had some very frustrated experiences on forums with people who do not understand basic solid mechanics and materials science. This is why I get a bit defensive at times, because I have literally spent 15+ years of my career focusing on this stuff! But it is clear you understand so I appreciate the dialogue and feedback.

I would be happy to send a mast for demo/review. Unfortunately I am back ordered 20+ masts at the moment, and must deliver to my customers before I send demos:) but if you tell me a length you’d like to review, I can get one in the queue. Thanks again, Kyle

[Saamgil]

Thank you Kyle for the explanations, it's really interesting. And a good idea to have an universal mast.

[ho-okipa]

Yes, I have had some very frustrated experiences on forums with people who do not understand basic solid mechanics and materials science. This is why I get a bit defensive at times, because I have literally spent 15+ years of my career focusing on this stuff! But it is clear you understand so I appreciate the dialogue and feedback.

I would be happy to send a mast for demo/review. Unfortunately I am back ordered 20+ masts at the moment, and must deliver to my customers before I send demos:) but if you tell me a length you’d like to review, I can get one in the queue. Thanks again, Kyle

It is funny because my company (Ascent Aerospace) also received a JEC awards in 2018 (but in asia) for the HyVarC molds (mix of Invar and cft)
https://www.jeccomposites.com/press/12- ... r-15-2018/
https://ascentaerospace.com/products/to ... d-tooling/


Yes for sure we will be very pleased to test your mast and I think that 85cm lenght is the most commun one. But I prefer to let Hadou discuss of it and test it as he is more experienced and skilled than me... but it will be a great pleasure to test it also.
Thanks for this discussion because it is very interesting to see a such technical and durable concept, which avoid to change the mast with each new generation of wing

[Project_Cedrus]

Want to make my next set of molds?

[ho-okipa]

Want to make my next set of molds?

Could be... but it is not the best way to reduce the price of your mast

[Project_Cedrus]

I thought you would be excited to see my new mast design
https://projectcedrus.com/general/intro ... lydesdale/

[ho-okipa]

I can only be won over by this new development… even though I understand that there is a marketing game to convince customers (like me ) but I see that the price increase is controlled. As you say, I think these few percent increases in stiffness will only be usable by a few people but will satisfy the majority.
It is a beautiful product with a real R&D approach behind. To be transparent, being with Gong foil, I think it’s a shame to pass on this mast because the Gong fuselage is very heavy , but otherwise I think I would have tried your nice product. Well done for the development of your mast! Wish you a great success.

[Project_Cedrus]

Thank you:) Just to clarify, this new model is not much (if any) stiffer than the Classic Cedrus. However, it is stronger. People still mix up stiffness vs. strength, which are two independent mechanical properties. In some cases, stiffness is actually inversely related to strength. For example, high modulus carbon fiber has lower strength than standard or intermediate modulus fibers. With this new mast, it is a stronger connection to the board as a couple users were bending the top screws of the Classic design. Same stiffness, more strength.

[Loic]

bon j'ai craqué ..... y a plus qu'a attendre qu'il arrive! Ca va bien allégé mon foil Fanatic HA qui est super bien mais super lourd!
Et le fait de pouvoir utiliser le mats avec pleins de marques différentes est super intéressant car beaucoup de mats carbone sont pas encore a la hauteur question rigidité !

[Saamgil]

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