My new build won't fly

Hi all,

Noob here with a new e-foil build! But it just won’t fly so I would appreciate any advice. Can you spot anything I have done wrong?

Motor: Flipsky 6kw 65161 120KV w/ stock propeller

ESC: Flipsky FSESC75300

Battery: 52V (14S4P) EM3ev - LG HG2: ~35A Continuous, 55A Max Burst Current

Foil: Gong Allvator V2 X-Over ALU - XL

Board: Gong HIPE EVO

You need double that for the battery…
And I’m assuming the vesc is not set up correctly either.

Thanks for the quick reply! So I need over 70 amps? I repurposed the battery from my old bike with hopes that would do it. This setup will do 5mph.

I have the same motor and the slightly less capable 75200 vesc so that’s not the problem.

Your board has lots of flotation volume so I’m guessing if will easily float you so that’s not the problem.

The original Flipsky prop is too big. I tried it and although it would move the board OK it is a lot better cut down. Various threads on that here.

@Jezza is very knowledgeable and has pointed you in the right direction with regard to battery choice and vesc setup.

Flipsky has several setup videos that you should have a look at to confirm your setup

This one the motor type is wrong for you

And this one that has the correct motor type for you

Flipsky uses these to get you started, there are lots of individual parameters you can adjust once that base layer is in place.
For example my max current limit value from the “wizard” setup was initially too low. I changed it to match the capability of the battery I use and it worked much better.

Good luck and keep us posted. This activity is so much fun once you get things sorted!!

Depending on your weight, you want around 100a battery amps and about 150 phase amps. These can be set on the vesc, but you will need to upgrade the battery to handle that too. The takeoff takes quite a bit of power, but once on the foil you’ll use a lot less power.

Just for reference, the amps are a bit lower for a more lightweight rider. I weigh about 67kg, and I need about 55 battery amps and 100 motor amps to initially get up. This is at 14S voltage level.

It’s important to spec voltage, because with a 7S battery (for example) I would need to double the battery amps to get similar power output. This is an oversimplified comparison but hopefully gets the point across.

A lot of drag is added to a setup that is already too weak amp wise:
1- three cables along the trailing edge of your mast is a lot of drag before take-off,
2- the same three cables up and down along the fuselage between the mast and the motor is not flush,
3- your motor above the stab (rear wing) offers a 65mm disk facing the direction of displacement. It could be more flush by adding a 3D printed half sphere or cone.
We’ve never seen the two last points on working efoils for some good reasons… :wink:

On working foildrives, the cables are either hidden or out of the water…

image

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@ggarff

EDIT: I don’t know what I was thinking when I wrote this reply - very insensitive of me. My apologies.

I have removed the offensive section of my original post.

Would that motor position even work regardless of battery and vesc capability? Wouldn’t that position cause the foil to want to pitch up??

How can I address cable drag? Duct tape is my first solution to a lot of problems, but not sure in this case!

I don’t know much about 3D printing. I’ll either learn or I’ll make a metal wedge.

Thanks for all the advice!! @Jezza @Foilguy @jkoljo

I’ll look at VESC setup and cutting down the prop. I will probably invest in a second battery to use with this (and for a new bike build.)

Yes the board does pitch up, but I am able to correct that with my


weight forward.

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Based on your photo the board is at a steep pitch. To be able to even start to foil the board needs to plane off. The rider in the photo is almost hanging ten so it would be very challenging to shift any more weight forward.

Different battery is warranted but you should also move the motor so it is attached to the trailing edge of the mast.

There are lots of photos posted here about the various approaches to making a “clamp” for the motor mount. Some are 3D printed and if you don’t know how to make in yourself you can likely find someone who could print it for you. The “3D files” are frequently posted so all you need to do is download the correct one

Other “clamp” designs use metal to accomplish the same goal.

The “clamp” needs to be sized for your particular motor and the mast it’s attached to.

In addition to the clamp part you should also acquire a “nose cone” that goes over the clamp so that water will flow past your motor better. Every bit helps.

Some people have 3D printed wire guides for the mast trailing edge that improve the hydrodynamics to some extent.

Most users here route the wires inside the mast for this reason. Just as a reference point I started with my motor wires external and enclosed them with wire guides. I recently routed the wires inside the mast and saw a 30% increase in max speed and ride duration. The general ride handling is also much better but that is more opinion than a measurable variable.

Lots of good info here. Use the search function and do lots of reading.

It works since the principle is used by Waydoo and Manta. The pitch up is compensated by the rider standing more forth a few inches but is not comfortable if too far forward when speed builds up.

You’ll learn a lot here, one of the first posts of this forum. @Gobbla and @mkefoil have done a very good job at the end of the thread.

image

How do you try to get on foil?

if you stand up to early you won’t
I have a similar setup. hipe 110 L and battery strapped to the rear. mast back as it goes.

I start on my knees, approx. where the inserts for the footstraps are. As soon as the board moves I have to push down the nose or it won’t get any speed. I only stand up when the foil is close to lifting - on flat water it takes just a few metres

you could try to get on foil staying on your knees, you can curve as well in this position (I often use this technique when exiting the swimming zone through the boat channel as it is easier than standing up
against the waves)

of course a better prop should be on your list as well as reducing drag but without proper technique you still won’t get on goil, especially with a week battery

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PVC flexible skirting band looks like a possibility - definitely a step up from duct tape!

We were standing and cruising around at 5mph to play with balance. My HIPE is 145L. I don’t see the difference between kneel and stand since that changes nothing below the board. Am I wrong?

That should help to move mast back though - thanks!

I did a lot of nose up plowing through the water stuff when I first started. I had the same motor, battery and foil as I have now. The board would even start to lift out a bit but then the pitch angle up would get even more acute and I would have to let off the throttle and the board would slam down. NOT FUN AT ALL😀

I watched some more Tube vid how to stuff and then it finally sunk in what I was doing wrong. Not enough board speed on the water BEFORE trying to fly.

When you visualize or recall how a plane takes off it rolls flat down the runway until it gets up to speed and then the nose lifts up gently and your flying.

If the pilot tries to take off too early in that sequence or tries to climb too steeply bad things happen.

The learn to fly while kneeling before standing is how most people learn and is how they seem to teach it at “learn to foil school”
Less chance of falling off and getting discouraged or injured I think is the theory

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