How long does your battery works?

I keep hearing that some can drive more than an hour …?
To my situation, my battery has 30.000mAH (14S Samsung 30Q) and I use the Flipsky 65161 120KV…
My battery is empty after a maximum of 40 minutes, if I push little bit more gas after 30 minutes. My GPS shows a distance of 8.5-9.8 kilometers till its empty…

My question, is that normal, or how do you drive that you can drive more than one hour???

What foil are you using?

This one:

https://hydrofoil.de/collections/foil-sets/products/hydrofoil-the-bullet-kitesurf-set

Thats why you only get 30-45 minutes…

Move to a high aspect or more efficient foil and you’ll possibly double your time.

So 14s10p 30Q , when you charged to know how much you put in or the voltage when you said it is empty ?
What average speed do you fly at 20-25-30km/h? ( with this type of wing for best range it is below 25km/h )
What prop to you use and esc you use ?

You can get at least 2.2A/cell so average:
3,7v x 2,2a x 10 x 14 = 1140wh

If you take 10km for 30 min : 20km/h average

It a little high : 114wh/km that speed with that foil even

So : falls ? Prop? Weight ? Low voltage end for the battery ?

Ok my charger shows at the end 14% -16% … (power to drive but not enough to take off).
ESC = ZTW Seal 300A
Prop: Maytech MTSP0504 7 1/4x5-A … but scaled down on the lathe.
Yes I think I drive with max of 20-25km/h… always with 60-72% percent of maximum speed.

Maybe its the foil… so I’ll try a different setup … Gong Allvator or which one do you recommend?

You can only use about 85% of LiIion capacity in our application since we cant foil well below 3,4v.
You should be at 60-80w/km @25kmh.
In the end you should have about 20km range since you have 1,5kw/h battery.

Use Metr and try modern foils to optimise.

And change prop now. I tried a couple of lathe’d down boatprop and they were 2x consumption vs FR and Flite.

normally i wanted to buy a flying rodeo prop , but i never got a response to any of my inquiries…

I think there is some potential in your setup, with a more efficient wing and a better prop. Then it also depends on your skills. When I started, I could only fly for a couple of seconds, therefore my logs showed between 100 and 120Wh/km, as a big part of my battey energy went into takeoffs. It also depends on the speed. Now I’m down to 76Wh/km with the 1600 cm2 RL wing, 83100 outrunner (no duct), Flite prop and a speed of around 25. I think I can get lower with slower speed and a 1.5 degree shim on the rear wing which makes the setup even more efficient with lowering the drag of the back wing. This of course also decreases stability and requires more skills. Your weight also has an influence, especially for takeoff.

I’ve ordered the FR Props here:

ATM they’re sold out but should be available soon again…

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thanks, i tried to write directly to the manufacturer … it is compatible /fixed with the motor 65161 (version with front thread) because when when i look at the drawing, there is no “rail” of the rear split pin…

David is a super busy guy. Let’s be happy he still produces stuff for the DIY scene…

His prop fits 6516X motors with threaded shafts:
“Sutiable for mytech and flipsky motor with M8 threaded shaft.”

ah ok, and do you have a tip how to get a propeller? I tried it last year but received no answer as written.

Patience, just patience.
It will probably become available again soon in this online Shop I’ve posted above. Just check every now and then…

The Flite propeller is readily available here https://www.custommotorsfrance.com/product/propeller-complete/

However, the shaft hole must be enlarged, but it has the following advantages

  • it is the cheapest in the EU
  • it’s probably the second most popular on the forum
  • in the summer it will be tested on my profi measuring device (I will publish the results), then I will make a small grinding of the blades, which will increase the efficiency (about 1 to 3%), which will allow to increase the speed of the e-foil or extend the battery life
  • it is designed to drive the Fliteboard e-foil, which is considered the best in the world
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Thanks a lot!

just ordered.

Here is a cross section of the propeller with dimensions


(the picture is from somewhere in the forum - I am not responsible for the dimensions)

It is clear from the picture that the hole for the motor shaft will have to be enlarged. However, enlarging the hole cannot be done by hand and with an ordinary hand drill - it would certainly create a crooked hole, which would cause the propeller to oscillate.

Therefore, enlarging the hole must be done by a professional with experience and equipment (reamer, bench drill, lathe, …), you can certainly find one in your region.

Thanks! will do it on the lathe

Focus your next effort on wing selection. You can rely on the above posts to help you choose, they are all very experienced e-foil users.

I would assume that the wing contributes about 20 to 25% to the overall efficiency of the drive. This range is further affected by how high the motor axis is positioned above the fuselage. The ideal placement can therefore be considered for the e-foil Fliteboard (https://cdn.motor1.com/images/mgl/1M9bK/s1/fliteboard.jpg). Placing the motor in the plane of the wing is ideal from a hydrodynamic point of view and brings a further set of design advantages.

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