Light assist Season 3

[Bzhwindtalker]

Hey all, here is the topic for season 3 developpement of light assist system.

Season 1 was when I sarted to foil, after trying a GONG wingfoil starter pack during the summer.

The Assist setup was a camdenboss 321, with maytech/ markerbase vesc, 7S4P battery and external motor pod. I learnt to foil/efoil with this system, along with pumping training. At the end of season 1, I passed 1 min pump time in pure dock start.
Highlights :
Starting with a 1050cm2 foil and 24lt board

First waves with chopped windsurf board and inset box

Season 2 was working on a under board setup with even smaller battery (12S2P 18650), for DW and pump assist. The first version had an external pod, and lasted around 1 year before having water ingress issues. The second unit has an integrated pod, and is now in operation. The files for the fist version have been shared to around 15 people, and at least two I know of completed the unit.
Tested and validated a 3D printed alu prop, in use since January 25.
Highlights :
Lake DW with the assist

Small swell with DIY 7’2 board

Super glassy session alone on the spot

Integrated pod

SEASON 3 = Middle class flite AMP

Goals and use case
Pump assist and wakethieving 40%
Surf 40%
DW 20%

12S1P 21700 with option of 12S2P pack

Able to start guys up to 80-90kgs (I’m 67kg)

Focus on reliability and serviceability over cheapest cost (lost sessions are a pain)
Swappable POD to experiment further with motor options and jet drives for safety

Save as much weight as possible while meeting project objectives (Season 2 = 3600gr all incl

Status
Ordered the parts (VESC, RX, nickel/copper strip) and have about 5 hours of CAD in this version.

This is not and efoil, and on the very light side of the spectrum for assists, as far as power and range goes. So I would compare it more to the flite AMP concept than say a foildrive GEN 2, apart from the slim FD.

12S2P option

12S1P option

latch integration needs a bit of,work

Internal layout

Cut out

Pod clearance could be a problem with some base plates

[Bzhwindtalker]

RESERVED FOR SHARING AND COLLABORATION DATA/LINKS.
reserved

Controller item	material / name	vendor	PRICE
vesc	HarryM BWESC - 80V 220A	Easy foil	167€ shipped
RX	MAYTECH	ALIEXPRESS	25€
Controller housing	Printed alu	CRAFTCOULD	176€ shipped
Connectors	MT60 and XT90	ALIEXPRESS	5€
Potting	BLUESIL RTV 1523	BLUESTAR SILICON	expensive
Latch	TBD (model SK3-002A)	TBD	TBD

POD item	material / name	vendor	PRICE
POD	PA12	CRAFTCLOUD	29,72€ shipped
Motor	6384	ALIEXPRESS	45€
PROP	Printed alu	PCBWAY	113€ shipped (probably cheaper at craftcloud)
Hub	PA12 PRINTED	WEERG	15€ (probably cheaper at craftcloud)
Screws	M4x12 *8, M4x35 *3, M5x60 *2 ,M4 stop nut * 3	ALI	15€
Connector	MT60	ALIEXPRESS	2€

Battery item	material / name	vendor	PRICE
Housing	home printed PETG	OVERTURE PETG	21€ per kg
Cells	P45B, P50B, 50PL	My company	5-10€ per cell
POGO Connector	RTLECS 7X2 POGO 2.52 pitch	ALIEXPRESS	9€ for a pair
Connector	XT90S	ALIEXPRESS/AMASS	2€
Potting	DIPOXI AMAZON CASTING epoxy (deep pour)	AMAZON	15€ per KG
Copper/nickel srip	21.3mm picth 165A rated	ALIEXPRESS	3€ per 12S1P

Misc item	material / name	vendor	PRICE
Remote	MAYTECH	ALI	85€
BALANCER	12S Capacitive balancer	ALIEXPRESS	25€
CHARGER	DESKTOP PS	Up to you	60-XXXX€

[Bzhwindtalker]

RESERVED FOR SHARED ORDERS/PARTS ORDER LINKS
reserved

[FoiledBySpoil]

Awesome. How small and light motor are you planning to try? I think the Amp Jet is only 25-28kg of thrust for 10 seconds (initial 3 second timeout before ramp-up) and it seems weight distribution and overall balance is a noticable feature.

[Toto44]

Nice idea. How do you place antenna? If the receiver is under water, signal will be very weak

[Bzhwindtalker]

Something like a 5065 or 5055 to get started, this has been proven to work in the past. Also interested in doing a jet pod, or a EDF style. Toutch down drag will be important to consider for this to work.

Safety factor is the main reason I am interested in jet. When things gets hectic out there in the waves, or just accumulating hours on the system, the risk of a prop ingury gets further and further away from acceptable levels.

@Toto44

How do you place antenna? If the receiver is under water, signal will be very weak

There is a antenna on the top of the unit, with fiberglass boards the signal comes tru the board, with full carbon boards you need to tape an antenna extension that stays on the board and goes to the deck.

Just having the unit antenna and the extension close together with no water in between is enouth to conduct the signal.

The antenna extension is just a lenght of coax wire with proper exposed lenght on both ends.

This has proven very effective, tested it for 1 year already.

[FoiledBySpoil]

For a Jet, and less drag, I would (and am) consider shaping a board with a «FD2» recess. Many of those these days, they get good reviews as well.

[Bzhwindtalker]

Adam Bennetts on Instagram: "This is the reason I never bothered with the SUP...

Inspiring!

[salomon]

I also just saw this board on another Instagram post and came on the forum to post it, but then I saw you already posted it.
This looks awesome!

[nekitesurfing]

Your versions and improvements made over time are great.

I spent a while working on a light SUP foil set up and if I had a choice between my prone foil assist board, tow boogie and the sup it would be the SUP every time. It’s just an easy session in waves. It uses a 6354 120kv motor and 12s1p and as an assist, it works very well. I love the reduction in weight.

My prone board is a stronger construction / heavier and uses 12s2p which is noticeable compared to 12s1p. On this board I normally Efoil onto the wave. I enjoy riding it but not as much as the SUP.

I’ve spent the last 12 months learning to prone foil without lithium. Probably about 50% of the time going out without batteries and enjoyed the challenge even though the wave count is far less. On small days it’s fun. On bigger days, I switch to lithium.

I would be keen to paddle into the wave more with my lithium assisted prone board but am more reluctant to do this with my hands and feet being so close to the propeller during the pop up at full throttle. I’ve slipped my hands a few times on the pop and had to react pretty quickly to take my finger off the throttle as I’ve fallen. The motor position in your version 3 looks pretty close to the rear of the board which would make me nervous. Is it as close to your feet as it looks? It could just be the angle of the photos.

A light weight jet style board like the amp with a hands free remote that gives you a quick boost but allows you to focus on the pop up would be awesome. I really like the look of the amp for my style of riding. It looks really well thought out. I look forward to seeing if your version 4 evolves into something like that.

[Bzhwindtalker]

Thanks for your insigths!

@nekitesurfing

The motor position in your version 3 looks pretty close to the rear of the board which would make me nervous

Yes, it is closer than I would like hence the concerns. Also had a close call during the holidays, that reminded that I like all my 10 fingers attached to my hands.

During the pop up on the prone, I can feel the prop wash in my back foot before it gets on the the board.

On the 7’2, this is lees of an issue for sure due to the longer tail. I feel it is actually less dangerous, as the prop is closer to the board and further away from hit risks.

The 7’2 is less than 5kg, and the takoon prone is 2.75kg. As my use case involves a lot of pumping around, and reconnect while pumping, I will probably use the prone more. The beauty of such system is that you can use whatever board you like.

What is the weight of the 6354?

Regarding the jet, I made some research and so far, I can not see how to get correct efficiency and > 25kg of thrust out of such system. Research continues.

[FoiledBySpoil]

A friend downsized a 3D printed scuba jet from Printables or similar page, and got decent thrust before the project halted. Model is Probably still out there.

[nekitesurfing]

The 6354 is around 500g from memory. Approximately half the weight of the 6384. It is good as an assist but It doesn’t have enough power to efoil though for me.

[Bzhwindtalker]

Do you flat start with the 6354? If so, body weight and foil size?

Flat start with 25lt board down to 25% battery would be a goal for this new system.

That is with a fast mid susrface foil like a 1201/new L+ barracuda (1300cm2)

In bad conditions, where you have a lot of chop, the power requirements gets much higher with a small board, I think this is why you prefer the mid lenght?

[nekitesurfing]

I can fly water start with it on the SUP but only by paddling hard and using either the 1300 png or the 1180 spitfire (big foils!). I don’t think the 6354 is what you are after. Saite make a 6364 and can customise the kv if you contact them. That might be the one.

[jbfoiluk]

Great pics and progress chaps, thanks for sharing!
Ive always preferred small boards for more dynamic manouvres & thought if you can loose 2kg with a prone instead of sup board and double or even tripple the size of the battery, this should make up for worse starting efficiency
depends if you prefer paddling or pumping i guess!

[Bzhwindtalker]

Made some more mods and simplification, then pulled the trigger for an order in alu printed for the controller part and SLS for the pod. This was the best solution I could think of to get the desired shape, strength and ease of potting/waterproofing.

Hopefully I did not do any critical mistakes

The controller part should come out at 410gr, I removed as much material as I thought possible. I will fill the gaps in the controller box with foam to reduce the water weight, and also try to design some printed parts inside to organise wires and reduce potting volume.

Received the copper/nickel strip for the battery builds, the first test housing is printing now for 12s1p

Edit : battery mock up 1, need more space in lenght and height, but width will work out.

[Bzhwindtalker]

12s1p P45B as 1st test pack for this new system. Lunch break battery build

[sat_be]

If you have space, it might be a good idea to put an additional fishpaper between the returning busbar and the cells.

[FL40]

Beautiful job Adam. You are always on the invention side! congratulation…