Light Assist Season 2

[Bzhwindtalker]

After quite a few revisions but enough rides to justify it in season 1, I will make a new lightweight setup to use with my takon slate V2 surf foil.
My goal is to use this setup for downwind runs, so reliability, portability and light weight will be the main focus.

I am thinking about the following parts based on my experience with first gen :
321c camdenbox or smaller
VESC MKS 84100HP
MAYTECH remote, OR some other BT remote (vesc has BT and external antenna)
6374 or 6384 with 3 blade prop
New quick release pod

Previous setup and issues :
Big board with battery in deck, board too heavy at 7.5kg dry. The volume gives good safety if anything fails at sea, but weight is a problem most of the times.

With the big foil and this board, it is possible to start when cells are down to 3v, as it really does not need a lot of power to get up.

4.2 25lt Surfoil with 1050cm2, not enough power to get started unless battery is full

Small HA foil is great to carve and pump, but would require higher power to start with a small board. I do not know if a higher power setup would allow me to start even when battery is close to zero. My idea is to have a light setup, you ahve to be able to utilise the full energy of the pack.

My current setup was 7S4P 21700 with a 6384 motor, and the 100mm tall camdenboss box. That comes down to about 3kg for the box, plus another 0.75 for the motor. With some waves, upwind/downwind and PNG 1300, I get around 1h of run time, for about 400 wh of energy. With a well tuned setup and with enough wind/waves, I think 250wh would be enough to have a good time, and comparable to the number of starts you could get on a downwind board with a paddle and good training,

First step is the new pod, using the same principle as the previous version but based on this one Hybrid Foils Nano Pod DIY - #41 by foiling_moose?

Now printing begins…

[Foilguy]

@Bzhwindtalker

Big board with battery in deck, board too heavy at 7.5kg dry. The volume gives good safety if anything fails at sea, but weight is a problem most of the times.

Curious if you ever tried to use a paddle with this setup??

[Bzhwindtalker]

Yes, the volume is barely enough for me to stand on, and the flat board shape combined with my lack of technique means I just went round and round, without a lot of forward momentum. I almost got a gong cruzader 105 lt used, but the board weight is similarly heavy.

[lishine]

@Bzhwindtalker

0.75 for the motor

970gr for the Ali 6384
plus the weight of cable and pod

[lishine]

Are you aware of this option for downwind?

'Store — FIVE-O WindSports
'PARAWING – Boardriding Maui

[Bzhwindtalker]

Yes, I am following the tests on french forums.
But I feel like e-foil will give more possibility, with a small board.

[Bzhwindtalker]

Right about the weight. May have to consider the maytech for this build as I have it available.

Here is the box for future reference.

Very happy with the first print of the pod in petg-cf. I will need to find a way to hold the door without a screw to make it really tool-less.

The inside part is being printed in tpu now, I print it super slow but the results are strong as hell.

Update : Weight of tha maytech without pod

[Jezza]

@Bzhwindtalker

May have to consider the maytech for this build as I have it available.

It might save weight, but the performance is terrible. Mine stutters and goes all over the place over 70% throttle.
My Flipsky 6374 is smooth as butter at all throttle values.

[Bzhwindtalker]

Wich prop? I heard the maytech with a tree blades is quite ok. Mine was always troublesome with the two blade, the main issue before I stopped using it was cavitation more than the lack of power.
Actually I have to weigh it again without the tpu mount to have a more fair comparison.

[lishine]

So, the Flipsky waterproof motor that you use is 6374 140kv?
Do you think this 6374 is sufficient for assist needs, let’s say a demanding scenario with a 90kg person, a small board, and choppy conditions?"
And with 12s?

[Bzhwindtalker]

+1 on choppy. There is a zone where bumps are not enough to help start and too much to have a clean run-up to get on foil

[Jezza]

@lishine

Do you think this 6374 is sufficient for assist needs, let’s say a demanding scenario with a 90kg person, a small board, and choppy conditions?"
And with 12s?

Yes easily. I am 99kg currently and deep water start the Flipsky 6374 140kv.

[Bzhwindtalker]

With what kind of foil?

[lishine]

Look at his other posts linked here:
'Flipsky's new waterproof 6384 - #63 by lishine
(I just transferred the discussion to the relevant topic)
It is an extreme configuration of Veloce XL with 24L board while weighing 95kg

[Bzhwindtalker]

the print of the inner pod part finished OK, but with some underextrusion. Still feels adequately strong.

I have been thinking about a under foil setup a la foil drive V2, as my box placement on the takoon board was still a little probelematic.

Found some waterproof XT90 for that purpose, thinking about printed shell and fully epoxy casted controller and battery. That would split the cost of a failure between the pack and the controller, the 84100HP is only 80€. If I manage to get a good enough signal in BT, then I do not need a extra maytech receiver.

So the idea would be to have a cast shape with the 84100HP, XT90 in and MR60 out, ideally using the built in BT for remote.

The battery would have just a XT 90 and be potted, using some sort of balance board or BMS cast into the resin.

[lishine]

FYI I and a few others build flat box on top of the board .
1 - it will not add drag like fdgen2
2 - can be adjusted to be above the wing, above the center of lift
3 - still not modifying the board

[Bzhwindtalker]

Interesting. For me another important factor would be signal reliability. Moving my box from the back of the board to the front solved 99% of my issues in v1.
Having the receiver under the board, with a CF board, is probably a receipe for problems.

With the box under, you have a much cleaner Cable routing.

I will draw something to get a cleaner Idea of options.

I ordered a 1201 front wing should be a great addition to the 1300 for downwind and surf foil in small swell.

[Bzhwindtalker]

here is the idea, the bolt would secure the battery. 12S2P with P45B or P50B, waterproof XT90. MR60 for the phases.

I will think about ways to reduce the cast volume.
50mm thick by 500mm long, 120 wide.

[Larsb]

@Bzhwindtalker

Right about the weight. May have to consider the maytech for this build as I have it available

Do you think 200 gram will affect riding in a way that you will feel? A sip of water before you go out (or the horror : changing into a wetsuit ) would be equal/more.
OK, it’s three batteries but still?

[Bzhwindtalker]

Well, Saving kg starts with Saving 100’s of grams. I am undecided for now.

Getting ready for test for the New POD today, with the 1300 and the 4.2’

Also redesigned the 3 blade hub to have the correct angle for fully folded blades.