Question Profile Go Foils ?

[kostantin]

Greetings,

I have serious doubts about this possibility.

Scanning, I don't believe that the scan is accurate enough, when it comes to the profile. We are talking of less then a tenth of a millimeter. There
a profiles that are extreme sensible at specific points.

Printing,

No material I know is even close on stability to carbon. You have freaking bending and torsion forces on a wing. A printed wing with a profile thickness between
8-9% will make all type of fancy things when you edge the foil.
It is not even good enough to use the printed parts as a platform for profile testing. The plastic is too weak.

Infill
Usually you print with infill. That means that the printed parts will fill up with water in the areas where no plastic is.

Putting carbon or glass on a printed wing. None of the resins I know stick well neither on PLA, ABS or worse Polycarbonate. You will loose any benefits of
a correct printed profile.

Where I see sense in printed parts for a foil are mock ups to pull molds. Either as positive or negative, but only if you are aware that the plastic is getting weak again at 43°

tks

Kosta

Just had a closer look on the picture. The wing is made as a three part. A middle section and two tips, left and right. The middle part is pure white, the tips blueish.
How do they have fit together when printed ?
You can do a a quick reverse engineer on this using the guys fingers to find the profile thickness. To keep it simple use a profile thickness of 10% No way !

When you have a closer look you can see the milling lines from a CNC.
Sounds a little fishy to me.
By the way a wing with such a high rake will have torsion on the wing tips high as Trump tower.
As long as there are no other pictures I would call this story bogus.

[TomW]

The wing is 3d printed and those "milling lines" are the layers of material laid down by the FDM printer.
I bet those wing tips are glued on with some internal rod or bar.
I'd be surprised if it held up. But an interesting tool for testing and interations.

[kostantin]

The wing is 3d printed and those "milling lines" are the layers of material laid down by the FDM printer.
I bet those wing tips are glued on with some internal rod or bar.
I'd be surprised if it held up. But an interesting tool for testing and interations.

Greetings Tom,

Lines of the FDM, hm I would say nope, He must have been printing flat. Means tons of support. Terrible surface.
Anyway, this is the mok up before pulling the mold
It shows the only thing that makes sense when it comes to printing foil stuff. My point of view.


https://imgur.com/SKyW4jU

The mold is finished but as long as the first wing is made I don't know if the pieces fit.
If I would knew what I know today I would say screw it.

tks

Kosta

[Europ2]

When you have a closer look you can see the milling lines from a CNC.
Sounds a little fishy to me.
By the way a wing with such a high rake will have torsion on the wing tips high as Trump tower.
As long as there are no other pictures I would call this story bogus.

After a closer look at the article, I have to second you overall.
First, those conic patterns can only be got when you have a curved surface (conic surface) milled into a multi layered material like G10. I can count 22 layers on the intrados of the midle part. Then, Javelin promised a lot of further reading on their blog that hasn't been published 11 months after the article was released.
Then, FDM prints parallel to the bed. This is obviously not the case on the picture, at least for the central part.

Nonetheless, even if they are probably cheating on the final result (the picture):
- we have never been so closed to a fully printed kite hydrofoil solution as J foils (America's cup ones) are now built using 5 or 6 axes articulated arms (the amazing video is around) applying carbon bands with fast hardener resins.
- we could imagine a 50/50 mix of technologies: the center arrow part that has to bear the strongest strain is in G10 and the wings in polycarbonate (the 450 3D printer working surface is only 1' x1' (30cm x 30 cm)

[TomW]

Hi Guys,
Not to get into a heated argument over this- But i dont understand why you think those are milling lines- when the information on the blog clearly states its printed.

the photo is showing a 3D printed part - Those marks on the surface are created buy the 3D FDM printer laying down the layers. the parts are printed with the layers parallel to the print bed.
I print out stuff regularly at work and see this every time on a FDM printer.
They have printed them out this way because the layers are oriented in a way to avoid delamination. It results in a poor surface- but they apparently took that trade-off.
The part is probably not that accurate, strong or light weight.
The wind ends probably are attached with some carbon or fiber tubes/rods inserted into the parts.
The support structure can be easily removed- as this kind of highend FDM printer has different materials for support structures and can be washed or dissolved off easily.


I agree that there soon (2-5 yrs) will be 3D printed wings - Look at MarkedForged X7 Printer- it has too small build volume at 330x270x170, but it prints both plastic and CONTINUOUS fiber carbon and Kevlar reinforcement into the part.
Check it out: https://markforged.com/x7/
This will allow rapid prototyping and faster development without tooling.
Plus it could disrupt the current production supply chain by allowing local production- something like the Adidas Speed Factory.

The robotic tape laying machines are a way to speed up and increase accuracy using traditional mold technologies. Reduces labor costs and waste. But you still have to have that high quality mold ( $$$$) and amortize it over time/quantity.
Still need a centralized factory. Still have a process of: make prototype- test- interate- THEN make expensive mold- sell parts until I have paid for mold . then i can start new development cycle. Too slow...

I think masts are very difficult- but see a future where we have a standardized mast ...

Be exciting to see what happens.