The Audi e-tron e-foil

Is Franz Hofmann, the builder, a member of this group?

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I bet he is lurking the threads :wink:

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That is a tiny tail volume. I can’t imagine that thing being statically stable.

Design looks great, but since I e-foiled successfully too now…I know that this concept has some serious faults… And this impeller setup is just a wasting energy thruster… Look at the big cooling plate below the board, then you know that they will pull 100A+ . And if the don`t use the battery from the e-tron then I assume riding time is less than 10minutes :sweat_smile:

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The mast seems angled backward, so even if the tail looks visually smaller, it might be not so bad :slight_smile:

So true :yum: Mono body/fuselage Concept - #11 by x-jets - Foils & Boards - FOIL.zone by @x-jets

Airplanes have a tail for a reason. That thing probably has a small static stability derivative and probably requires a bunch of control input to keep it from flying away.

You can see the effect of tail volume in the section on static stability here.

I bet that Xjets foil doesn’t even work.

There’s also Flying Wings (Flying wing - Wikipedia),
but you need a special foil section for it to allow to be “flyable” or statically stable.
Since with aircrafts you set your CG once and control the plane via control surfaces, it’s hard to compare to the weight shifted control we do on our foils.
I personally don’t think a Flying Wing would be a good setup for a foil unless you have control surfaces (ailerons) and a processor/controller that helps you keep the foil level (which would be kind of an autopilot, or controller like they’re used in drones)

As for the Audi Foil, I’m not really convinced of the setup. The backward bend mast is just a design thing I suppose, and the tiny tail looks really small.
I’ve seen that thing in Kiel last year, I was there when they did a promotion run during “Kieler Woche”. Not sure how long they’ve been in the water, but it didn’t look to “smooth” and only starts foiling at quite high speeds I believe (i don’t have any data, just from seeing it)

Apparently will be brought to market by this company with some possible cross-branding with Audi e-tron: http://aerofoils.de

Pre-order is live. $15k USD with production starting in August 2021: Products – Audi e-tron foil by Aerofoils

Pros: safety (first commercial impeller), direct drive [looking forward to knowing the motor details (Kv, manufacturer, slot/pole number)], remote control, battery quality up to Audi electric vehicle standards, tbc’d…

Cons: price (15,000€ including taxes + shipping for EU residents), is 32kg really “lightweight” ? No information about ESC, tbc’d…

Questions: how much energy (autonomy) is lost in this impeller compared to a propeller system ? What happened since the 2018 prototype, the hull cooling system seems abandoned.

Audi e-foil 4x
High AR wing

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I’m not sure that a company like Audi would implement a standard water jet knowing it’s inefficiencies. Maybe they’re using something like this.

It is not Audi, it comes from Aerofoils Gmbh not Audi, they just use the Etron name for marketing purpose. I think in agreement with Audi

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I don’t think you really know enough to comment :thinking:

If you say so… :sweat_smile: and you know more about it…tell us :innocent:

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It’s finally available at the e-surfer Shop. The Audi e-tron Foil by Aerofoils. Shipping starts end of February and we will get our demo board this week, which we will offer for test rides in Berlin and later on other locations.

Audi e-tron Foil Highlights:

  • Fully shielded drive for maximum safety
  • Intelligent remote control with high-resolution color display
  • Minimal water resistance for maximum glide
  • 80 cm mast with low motor for maximum height
  • Highly intelligent battery of the latest generation
  • Two radio receivers for constant connection
  • Maintenance free gearless motor
  • All carbon fiber construction for maximum robustness with minimum weight
  • GPS & Gyro for maximum safety
  • Made in Germany
  • Free smartphone app

Audi e-tron Foil – Technical data:

  • Top speed up to 50 km/h*
  • Range up to 120 minutes*
  • Up to 40 km range*
  • 32 kg weight including battery
  • Tested for riders up to 100 kg

*Depending on setup, driver weight and conditions.

To answer the question above. Aerofoils is an Audi AG spin off. Audi is an investor and licensed the name to AeroFoils. Audi is also supporting Aerofoils with Know How and testing/manufacturing facilities.

I did ride an prototype in 2019 and the latest version in November 2021. It glides really very well and as you would expect from the Audi brand, it is using only high quality materials. It’s very well designed. Can’t wait to see the Avengers or 007 riding it :wink:

Andreas

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Then they should show a rider that’s 100kg and not a rider that is around 50kg in the video. Show the foil performing to the max of its ability and I will be convinced. However we all know that the jet, while safer than a prop, still has 30% less performance so it will just never topple the other players…

Hi @Jezza , it is not a jet propulsion. It is a fully shielded propeller.

At my test ride in November I had 92 kg plus 5 mm wetsuit, vest and helmet which makes it almost 100 kg. It had no problems at all to lift me up.

Spring is coming, so you will see some bigger guys like me riding the Audi e-tron Foil on video. Stay tuned …

That pretty much looks exactly like a pump jet propulsor which will have less efficiency than Lift and Fliteboard props.

Its by definition a jet. It probably has an impeller design instead of prop and definately uses an end nozzle to increase outlet velocity.
Try to post normal consumption in wh/km as soon as you can Andreas. It looks really sweet with jet, but the 30% extra consumption is quite likely…