Use the loft command between two mast crossections
Clever idea! We created holes through the foil and filled it with glue. It increases stiffness, but also stops delamination!
Yes the loft command, I´ve read about it but I´ve never done any real cad before, just tinkercad. But 360 seems great when you learned how to use it.
My mast is based on a E836 Eppler foil and I´m printing them in 100mm parts. My biggest problem is how to get the epoxy/carbon to really bond to the mast surface. I´ve heard the the bond is more mechanical than chemical between epoxy and PLA so therefore I designed it with small grooves. But now I heard someone mention that the 3M spray mount make a good bond between PLA and the first layer. So maybe I give that a try first.
Let me know if the spray works!
If you are in doubt about the adhesion, I would go through the structure with some fiberglass to link the sides. and form a multiple torsion box, like a snow ski construction.
I had no issue with adhesion between the glass and pla! The 3d printed mast is basically just for the shape, it has no structural integrity! All the strength is from the laminated glass and carbon !
Check out this post about how we build our own hydrofoils!
yeah i have basically done the same but without filling them with glue, still plenty strong.
I want to use the same solution for mast and plate.
how many layers did you use for the mast? and remained it stiff?
hey there, sorry for the late reply. I have bee away over Christmas.
I have currently used 3 walls 40% infill PLA for the mast, printed in 100 mm sections.
I then super glued them together and used filler to fill any cracks and warps and did 4-5 layers of fiberglass with extra strengthening layers around stress areas and joints.
I still havent finished mine but I intend to use two layers of Carbon, one at a 90 degree angle and one at a 45 degree angle for finishing.
hope this helps, David.
Hi David, thanks for your reply and informations, right now i’m starting to print some section and look for lighter solution that i hope to share soon to compare the results.
Hey David, really impressive what you are doing and I love the pics of your workshop. I’m based in CHCH last 10 years but as a young fella I did a lot of windsurfing on Tamaki Estuary spit and in the harbour generally, awesome place. I think your designs are looking good and love the foil and mast construction method you are using. I’m in the process of building a large high precision and high speed 3D printer and I had considered it for foils of all sorts, so you’ve proven this well for me and its given me great confidence its a good way forward towards low cost practical foil building. I have been mulling some plans for my own outrunner ducted turbines in my head , based on a halbach magnet configuration and initially I’ll use 3D printed motor parts too, although I may also try to machine up a mould and make a more beefy carbon turbine outrunner if it proves powerful and worthwhile. Keep up the good work I am watching with interest!!!
I followed Hiorths recommendation and it works like a charm. Take great care in making the “bag” airtight.
I had some small leaks and it has a huge impact on the end result.
I put a timer on the refrigerator compressor to make it shut if after the resin had hardened.
Thanks again Hiorth for the documentation.
Thank you for the interest, we have more or less finished the main components of the board.
#d printing and fiberglass works a treat, only part left to carbon fiber is the mast, once I have that done I will post pictures.
At the moment we are currently looking at a compact twin jet drive unit using mainly electric skateboard electronics to bring down the price. Because Eboards are becoming more popular the price is also becoming more affordable, we are also working on another water vehicle so hope to use the “modular twin jetdrive” for this as well.
Keep me updated on your success.
@DavidC the twin jet sounds interesting. Is doubling all components for a twin setup with eskate components still cheaper than the common SSS motor + gearbox set up?
Did you find a battery solution? It’s the final piece in the puzzle for me and I’m going to need it soon to test on the water.
No I have not found a resolved battery solution, I have two 6ah 22.2volt batteries that i will use for testing and gathering data. I will then buy a battery (china) that is adequate for the power I produce.
Yes, I am getting fed up of waiting and searching for a direct drive solution and there is currently a twin water cooled esc and 80mm water cooled outrunners on the market. i am thinking twin 80mm impellers. keep me updated on your build. are you in Auckland?
@DavidC do you know a good battery supplier that can ship to NZ?
Those 6ah batteries will be good for testing out of the water but can they handle 100A discharge?
Yes I’m in Kohimarama, Auckland.
The hobyking 20ah 6s ones should work fine I think. if I recall from the eskate forum the mulitstar lipos have like a max 4 or 5c discharge although it says 10c still at 5c that’s 100a. I’m also in Auckland. Buy them separately so they send them separately and you should dodge import tax
i might try this, i ordered together before and sent them back once i received the tax invoice of 300 dollars
I dont, have a look on alibaba and email a few suppliers giving them your request, shipping is stiil quite expensive.