How thick is it ? The standard for efoils is in the 15mm region. If above 20mm, it will become a source of drag.
Beware that the leading edge (LE) insert and the trailing edge one (TE) are usually not identical. TE is sharper and longer, 1.5x on the Gong mast. Since you print them, it would be interesting to test both configurations though: TE = LE and TE = 1.5 x LE.
Hey SoEFoil,
The Extrusion is about 18mm thick, I checked it beforehand and it shouldn’t be too much drag.
My first test will be with TE=LE for simplicity, I guess/hope it doesn’t make a huge difference.
I know that my setup is not the most optimized but considering its full DIY I try to do everything as good as I can/have the tools and hopefully get a decent result.
as for charger:
there are several chinese CC/CV 12S chargers but they get quite expensive really fast and you don’t have any control over them. I looked around amazon and found this:
https://www.amazon.de/gp/product/B074FXPPLK/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
This is a DC/DC boost converter with 0-60V input and up to 120V output (claiming “600W”, 
)
It has:
- Current limitation 0.01 resolution
- adjustable voltage
making it a perfect CC/CV charger for the foil.
I power the charger with a 24V 150W MeanWell power supply I had laying around.
currently printing a case for the charger:
and the best: its only 20€ and since you can power it with ANY power supply (<60V) this is a no brainer for me.
PS.: I checked the output Voltage with my Fluke and the calibration on this thing is quite good (<0.05V difference between voltage displayed and voltage measured with calibrated Fluke Voltemeter)
That’s a clean battery build! Two questions: can you post purchase links for your parts (box, connections, etc.) Also files for 3D. Your bus bar prints look great.
Sure:
Finding the right batterybox was a huge pain.
Battery box:
https://www.reichelt.at/kunststoffgehaeuse-300-x-230-x-86-mm-ip65-rnd-455-00203-p193417.html?&trstct=pos_1&nbc=1
18650 space holder:
https://www.amazon.de/Lithium-Akku-Verbinder-Batterie-Halter-Bracket/dp/B071ZMJRSP/ref=sr_1_3?__mk_de_DE=ÅMÅŽÕÑ&dchild=1&keywords=18650+halter&qid=1587504935&sr=8-3
Batteries:
https://www.nkon.nl/rechargeable/li-ion/18650-size/k-tech-inr18650p-2500mah.html
Busbar Cover (with insertet 2.5mm² copper wire, from house installation):
Single cell fusing wire:
Fuseholder midiOTO with 125A fuse
Used generic 10mm² copper wire for the main current line
As for connectors I used 2 XT90S female plugs with a 3D-printed panel mount (epoxied the panel mount and sealed everything up with Inotec Powerbond sealant, tested 30 mins in bath tub → no leaks)
Sealant:
XT90 panel mount:
https://www.thingiverse.com/thing:3606959
I also fused every wire to my charging BMS (not yet photographed) with 5A 6x30 fuses and also added an extra 10A fuse for the charging input.
The two XT90: one is to the ESC the second one is for an XT90 loopkey, to start the foil up (anti-spark)
Hello and what about desbalancing cell. Low voltage is the mean cell voltage. But you can have one very low cell…be carefully
Thanks! Yes, battery boxes are tough. Ended up making mine out of acrylic. I especially like the bus bar holders you made as I soldered up ladders. Your box is a bit too thick for my board, but I’ll incorporate some ideas into my battery 2.0.
Hey Vincent,
I made other 18650 batteries before and with high quality cells there should be no drift of the individual cells. And since there I have a BMS for charging after every charge my cells should be balanced out again, so no worries there.
I replied in another old thread concerning my motor 
but i want to post it here aswell:
I forgot how the 80100 assembles together, everything looks fine but I got 2 washers and I only know where to put one of them, or do both belong here (picture) ? Anyone rememebers?
DIY-Foil Progress:
my foil is currently under construction so to say:
This is how everything comes together:
Big-Wing:
Small-Wing
Mast:
Wow! I’m going to follow this. Great work. We are working on a data-logging system with an end goal of using machine learning algorithms to tune parameters like propeller diameter and pitch. We can modulate these parameters because we can 3D print propellers quickly. This is really exciting for me because your method allows for making hydrofoils quickly. It would be incredible to have the algorithms also optimize metrics about the wing not just the propeller.
its hollow but quite thick, ist 20x20mm profile and has 2mm thickness. I think it will hold up nicely, can say more after my tests 
and the screws are palced on the wall thickness, or squeezing the profile? Nevertheless, I am sure it will bend. Please keep us updated.
You need a other Prop 
Greetings Frank
For your reference; a Gong fuselage is 30x30 solid aluminium. The 20x20 hollow profile will get you up on foil but is way to twisty to hold you stable when flying.
What is with your build?
Last weekend I was foiling in Seekirchen
Hi Strassa I liked your charger idea so much I bought the same one. Do you have the stl file for the case your printed?
Hello @strassa I m in the process of printing my foil as well and plan to laminate with fiber glass and carbon. Did you design this foil yourself or found it online ? Did you print it full or what % infill ?
I m doing some test using this foil :
Already printed it once at 100% scale, it’s around 54cm wide close to 60 “unfolded”,
I m now printing at 150% on 2 axis (wingspan and thickness) and 120% on 1 (chord).
That will give me over 80cm of wingspan (I want to start surf/sup foiling before moving to kite and efoil in the future) so I figured bigger is better as a beginner.
Tried 15% infill on the first print and it came very sturdy, I moved to 5% infill on the bigger version and its a bit weak (I can feel it creeks when I pushing on it, I hope it won’t crush once I vacuum and fiber my wing 
we will see !
I have also thought of printing at 0% and fill the parts with expending foam to give them a foam core… that will probably be my next experiment.
I m pretty new to the forum but don’t see much printed foil and can’t really find successful build with that tech, I hope I m wrong and that we will be successful.
I ll make my own build thread soon once I have enough progress, hope we can share and help each other.
Cheers
