eFoil build Document

EFOIL.builders Builds
1

Hello eFoil community, this post is to just be a statement on my upcoming project. I plan on creating an in-depth document that will contain all the necessary information for a person to read and build their own eFoil. This document will contain all CAD files and code for the different systems present on the board. The document will be highly technical but easily comprehended.
I am almost a newly graduated mechanical engineer, where I focused many years on system design and improvements. I have extensive training in CFD and CAD software as well as data analysis from the electrical components present in an eFoil. I also have built many surfboards of all shapes as i am lucky to live close to a surfboard supply company. I have wanted to start this project for many years now but am limited to funds due to the current world situation(COVID-19). But in a positive point of view this time for me is the best time due to all the FREE time available. Therefore…

For my efoil my plan is to create a highly engineered platform in multiple phases.
Phase 1: design time! this will take a long time. 3d model all physical aspects and create electrical diagrams.
Phase 2: will be the development of the electrical system, as there are many on the market I will utilize the many tools I have obtained to create a system that is easily adaptable to specific riders and conditions. For the battery system I will be consulting other engineers who have knowledge in the field.
Phase 3: remote. I will develop a completely new efoil remote that will utilize 3d printing and some craftmanship to obtain waterproof/shockproof remote. ( all files and PCB boards and code will be provided)
Phase 4: Board building time due to my experience in this sector will be the fastest. CFD software will be utilized to help find redundancies in the physical design. A prop will be machined out of aluminum.

This document will most likely be a couple of hundred pages long composed of many figures and illustrations.
I want this document to help the community in the long run and will make it available to all who wish to use the information that will be provided. if you wish to follow my build please be patient and most importantly PROVIDE feedback or advice anything really.

Best,
Dave

7 Likes
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This is quite the undertaking! I support the initiative though, I think it would be useful to have a very detailed document that any beginner could read.

I suggest you start by reading this forum in its entirety or at least skim through all the different builds. You will find A LOT of information on all the different parts you might need in your build! I personally have like 6-7 days of reading time on this forum lol (FYI, you can find yours in your profile summary). You don’t need to go to this extent though.I am looking forward to see your remote solution. I’ll be following along! Good luck :blush:

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Thanks !
I am mostly doing this project because I take a lot of enjoyment in creating detailed documents and in hopes of giving it to friends so I don’t have to ride alone !!. Also because to me it would be a product of what I have learned throughout my education and how I will apply it to my hobbies. I will definitely read it all through and take notes really appreciate the help!

2 Likes
4

Very nice initiative. There is so much work for a solo man and in perpetual evolution that I have a suggestion. Why not using a mind map tool or a huge WIKI ? The writing could be parallel. A few people could help you out. You could create commits… in a pdf format if you like.
Best solutions have emerged like the forced flow watercooling through a pod nose inlet that cancels the pump need thus simplifying the wiring diagram thus the electric case (see @michion v2 board simplicity)

Then there is the matrix of options not easy to translate into a single pdf
1 - Board fully home-made or modified existing board ? Electric box: external plastic case or internal ? With or without hinged lid ?

2 - Electrical aspects
2.1 Wiring diagram: the minimum setup is: a motor, an ESC, a remote receiver, a battery and a protection system (fuse or ). A switch can be added to disconnect the battery during the transport. Possible sensors: temperature, water detection, etc
2.2 Wires and connectors tbc
Wire gauge AWG8 or AWG6, … 8mm connectors, AS150 (AS = Anti spark), XT90,

3 - Drive train,

  • 3.1 motor: we have a wide choice of possibilities today
    Inrunners : sold waterproof: Flying Rodeo or 6516x 100 and 120kv from Reacher / Flipsky / Maytech?
    Outrunners : need DiY waterproofing : 80100 replaced by the 63100 (both APS) …6384 from FLIPSKY
  • 3.2 propeller
    3.2.1 Fixed or folding
    3.2.2 DiY (3D printed, cast) or commercial (Flying Rodeo, Russian manufacturer, Solas, Chinese, new comers)

4 - ESC:

  • 4.1 position: above the mast for simplified electric box (FliteB, Pegasus, Mantafoils, Waydoo One, …)
  • 4.2 VESC or non VESC, max voltage 6, 10, 12 or 14s ? ESC with included BEC and anti spark solution
    Lowcost Flycolor 60usd type, middle cost Flipsky 12s waterproof VESC, or SEAL 300A 14s non VESC, quality: Trampa 75/300 or TeamTriForce , high end MGM Compro 500usd+, …
  • 4.3 ESC programming + modes (BDLC, FOC, ) + main brand user-guide links
    _Non VESC
    _VESC (motor-batt-ABS current, throttle calibration, ramping time, stator compensation, …)
    Trouble shooting guide: symptoms/error code and solutions in a esc/motor use-case matrix (see @User1 10 - Trouble Shooting guide below )
    As your esc/motor/wire length /connectors setup is unique, rerun a motor detection in suitable conditions : unloaded motor, so no lip seals; cable lengths in final configuration
    non VESC: …
    VESC: list of error codes with solutions, list of symptoms with solutions see ch 10 - Trouble Shooting guide below )

5 - Battery : commercial or DiY so far Li-Ion but Supernova should unveil their much awaited LTO cell based solution on the 2020/06/18 - probably 6s

6 - Hydrofoil front wing choice:
Commercial OR DiY : which surface, footprint and airfoil section?
Trend: new large surface high AR low thickness ratio (UniFoil / Windfoil wings / RL efoil wing / Gong Veloce 8%) should open a new way to low consumption drive trains using 6s batteries and low cost 6s ESC’s (see 8-Budget efoil here below).
7 - Remote control:
Commercial (MAYTECH, Waydoo (possibly August ) ) or DiY (Yahef, samisin, yours, new to come, …
8 - Budget efoil chapter (sub 1000USD) : a summary of the best practices

  • The 6s phylosophy by @JetboardCologne (60kg rider): set up for E Foil under 450usd :
    Motor: waterproofed outrunner Flipsky 6384 120kv (avoid APS)
    ESC: 6s 150A Flycolor boat: FlyMonster,FlyMonster Series,Boat ESC,Products,飞盈
    Battery: Turnigy 6s 12Ah x2 in parallel = 6s 24Ah
    DiY Propeller: 2 blades, 170mm (instead of 140-150mm in 12s with a 100-120kv inrunner)
    Source @V_S 140mm increased to 170 and z-axis multiplied by 1.3
    Amps and power drawn: take-off / flight: 80 A / 32 - 35A - Power: 1775 / 720W
    Ride time: 35 - 40min
    Speed: 25km/h
    Front wing: Bic Techno windfoil 85cm span, 1300cm2 (Kerfoil design)

  • for heavier riders needing 120A to take-off who want to keep amps low:
    a foot push rod along the mast to lower a flap to double the lift (at constant speed) and trigger a board take-off at 40A instead of 120A ? Should allow the use of a low cost 6s 60A ESC or 70A MK3 VESC ? The wing must be flat see Taaroa iUP thread.

9 - Buiilding and using your battery charger

10 - Future developments
IMU - Artificial Intelligence for which use ?

11 - Trouble Shooting guide
Motor-ESC use cases.
(1) User1 use-case VESC ESC figures for 65162 motor + Flipsky FSESC 200A VESC
(…)

(2) List of issues and solutions that have worked in the past
With Flipsky FSESC 200A waterproof
Reminder: as your esc/motor/wire length /connectors setup is unique, rerun a motor detection in suitable conditions : unloaded motor, so no lip seals; cable lengths in final configuration
Error 1 (Err1): ABS_OVER_CURRENT
Sol Err1.1: Abs Max current has to be a lot higher than motor current. Set Abs Max current to 200A and max motor current to 160A. Enable slow abs max current.
Sol Err1.2: install no_HW_limit driver if available
Sol Err1.3: check … increase

Error 2 (Err2): R0 is 1
Sol Err1.1: tbc

Issue 1 (Iss1): motor cogging and stalling during startup
Sol Iss1.1: check that motor is running on 3 phases instead of 2
Sol Iss1.2: Modify “Stator Saturation Compensation” from stock 0% to 10%, from 10% to 0%

12 - Advanced Trouble Shooting guide
Structure of a MotorConfig.xml configuration file

… and so on.

[Revisions]:
200621: added 9 - Buiilding and using your battery charger

13 Likes
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Thanks for the info , will definitely look in the implementation of a mind map.
I Am currently looking into Flipsky 300 A 60 V ESC and Direct drive 120kv motor.

Direct drive is the goal as it will hopefully with proper sealing and preventative maintenance will be less of a headache through out its life span.
Do you know of any threads where others have put it to the test? I haven’t looked at the other ESC options yet.

And for the foil that would be awesome if we all can find a way to incorporate Fowler flaps into a foil . I haven’t seen it done yet on a hydro foil of this size yet. This will definitely be a tough design to achieve and will be needing outside help

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We could do it as Moths do, between the wing body and the flap they mainly use a SikaFlex gasket with strong binding properties. DiYers sometimes use kevlar fabrics.
The first flapped front wing will be on the market very soon, designed by the French from iUp - iUp Page | TAAROA
Taaroa iUP, surf/sup foil with GBS, IA driven - Info for the DiYer - Foils & Boards - FOIL.zone

200401 iUP 02
200401 iUP 02672×672 52.3 KB

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I definitely think this is possible on a diy level, but major concerns would just be the time frame and development of the system.
I just quickly watched the video provided by the company and it seems they used the configuration of standard flaps. This design keeps the system simple and effective but you are sacrificing drag for more lift. Also, this design is to help the maneuverability of the foil.

From an initial standpoint, I think implementing a fowler flap design will create a more stable foil with significantly less drag if placed correctly when a rider is in a start-up mode. Then after startup and at a stable speed, the flaps would be retracted to form a standard foil shape.

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This link allows access to a document worth reading on propellers

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You propose a ESC: 6s 150A Flycolor boat with a 6s battery on a 120kv motor…

That should be a theoretical max 25.2 * 120 = 3024 rpm (too little for anyone heavier than 70ish kg?)