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All Electric Proof of concept Prototype


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The link works …. It’s just it’s a link to THIS post so not useful. 
 

as this airframe has been knocking around for 6 yrs and has been through company mergers and a lot of money and two motor providers I’d like to know if the post was for something new. 
 

it never really added up when I read about it

- only 200kg payload so toothbrush and credit card if you have a passenger.

- never clear how much battery capacity they actually have to give the claimed 3.5hrs and at what actual cruise/reserve the system was 
 

 

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I don't understand how an electric aircraft is going to be used for pilot training? If a pilot needs to get somewhere, he needs to be able (and trained and licenced) to drive an IC-engined aircraft.

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Still around as of August last year.

eFlyer

 

Company Website

 

3hrs endurance @ 73knots, or 220nm range, I'm guessing range reduces at higher speeds.

204kg payload - remember, no fuel has to be added. 2 x 85kg passengers leaves 34kg for baggage.

 

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ARTICLE QUOTE - "Bye Aerospace has been working on its electric aircraft concept since 2007 and is still in the process of delivering its first airplane".

 

I don't think I'll be holding my breath waiting for a sales-ready electric aircraft from this mob. As with many public companies, as long as the company coffers are regularly replenished by suckers with a few million to throw away - and the money is still there to pay executives salaries, the leases, and replace the corporate Beemers and Audi's - then the CEO and his minions are generally very happy to keep things trundling along at that rate, with no real pressing, fixed timeline, to deliver the goods.

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56 minutes ago, RossK said:

Still around as of August last year.

eFlyer

 

Company Website

 

3hrs endurance @ 73knots, or 220nm range, I'm guessing range reduces at higher speeds.

204kg payload - remember, no fuel has to be added. 2 x 85kg passengers leaves 34kg for baggage.

 

😂 😂 

oh bless - you honestly believe the average Joe n Jill are 85kg.

 

and I followed this development for years and never heard of any flight more than a couple of circuits so I believe nothing about it’s claimed endurance or range. 

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1 hour ago, kasper said:

😂 😂 

oh bless - you honestly believe the average Joe n Jill are 85kg.

 

Well, I'd consider my wife and I average, neither of us are skinny or short and we're 165kg combined

Add to that, everyone I know who flys regularly has lost weight for the sole reason of fitting more baggage or fuel in the plane.

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At least all these weasly idea’s give us a source of entertainment!😂 I just did 450nm in 2.4 hrs, 70l, wake me up when I can do this in some EP fairy machine for just a few cents😂😂

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14 hours ago, red750 said:

Sorry guys. Looking for more aircraft to profile, I came across the link and thought it was more recent.

All good Red, still current

Latest eFlyer 2 Article

 

Yes, its likely to be just hopes and dreams, but if it can do the numbers they claim and continue to improve that range, it starts getting practical - where to charge it however???

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I'm wondering if the technology is being pulled from the wrong places.

there is a large growing market for electric motorcycles. Ducati release their new electric race bike today.
all the emphasis on a motorcycle is weight - not really a concern with cars and trucks
 

"According to Ducati, the MotoE racer has an output of 110kW (roughly 150 horsepower) and 140Nm of torque. As for the battery pack, it’s comprised of 1,152 cylindrical 21700 type cells – the same cells you’ll find in a Tesla. It weighs 242.4 lbs. (110 kg) and has a capacity of 18 kWh. What’s interesting about the pack is its orientation – tilted back within the chassis – and the fact it’s not a purely rectangular shape but rather a complex shape meant to fill the void within the middle of the bike. Naturally, it’s housed in carbon fiber, and like the Panigale V4 production bike, it’s attached to a front subframe, making it a stressed member of the chassis."

probably take 30-40kg off for wheels, tires, frames. makes it look alot better to strap in an aircraft.

plus its built with air cooling in mind.


the idea of using the battery as a stressed member also helps lighten the complete package.
my take away from this is that the best possible way to make it viable is a ground up build. not a conversion of existing aircraft.

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31 minutes ago, spenaroo said:

...  As for the battery pack, it’s comprised of 1,152 cylindrical 21700 type cells – the same cells you’ll find in a Tesla. It weighs 242.4 lbs. (110 kg) and has a capacity of 18 kWh. ...

Hmmm  I'm using LIFEPO4 chemistry which is not the lightest lithium battery (but quite a bit less flammable) and I have a 14.5kwh battery setup for the Sapphire that with the BMS weighs in at 88kg before I start slotting it around the airframe. 

Prorata for the capacity difference my setup is exactly the same kg/kwh as Ducati get ... maybe I am on the right track. 

 

Admitted my 88kg does not include the battery boxes I've built into the new wing and behind the seat but they are all vac bagged carbon and very light so my system is stacking up so far.

 

My concern with the Eflyer is that they are going to be using a lot of power even in economical cruise to stay up there so they will need lots of battery ... and these things are still heavy per kwh. 

 

Just think

- Eflyer has 110kw motor,

- guessing it uses 30-40kw to fly at endurance

- they claim 3hrs endurance

- they need around 90-120kwh of battery

- LIFEPO4 systems weigh 6kw/kwh

This would imply a battery pack of around 540-720kg

That is not believable.

 

Even if using really good (very flammable) lithium batteries its not much better - the current Tesla 100kwh lithium pack comes in at 625kg.

 

I just cannot see how they can possibly get the performance they claim out of the available technology.

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https://www.motorcycle.com/features/world-exclusive-ducati-v21l-motoe-prototype-first-look.html

 

is the article I quoted from, worth a read to see just what the obsession with weight entails.

and better specs, and how its all designed together to achieve it.

I misread, your right it is 110kg is for the battery (I only skimmed the article before work) the total bike weight is 220kg, a Panigale V2 is 200kg kerb weight (closest performance specs).
probably take 20kg out for a race bike for around 180kg (no lights, weight fairings and exhaust)

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And the reason this is all terribly hard to do ... energy density and conversion to work.

 

I have an electric motor and control system that is VERY efficient in taking kw in the battery and converting it into rotational kw at the prop ... I'm looking at around 90-95% efficient.

 

That means my 14.5kwh of battery can be converted into 13kw of work ... and that 13kw of work weighs 88kg.  That 13kw will keep me up around 2hrs.

 

A small two stroke petrol engine to do the same work runs at 9lph in cruise ... and that engine is approx 9kw of power in cruise to the redrive which as a belt is around 90% efficient so its near 8kw of work.  So 2 hrs of petrol is 18L ... and that is 13kg.

 

Battery system is 6.76 times the installed weight of the petrol equivalent ...  and believe me working out how to shove nearly 90kg of weight into an airframe that is only 90kg AND keep the CofG in an acceptable location AND still have room for my well padded body has been interesting.

 

Yes the electric motor is lighter than the IC engine but at the low power end of aircraft the saving on motor is not really helpful to offset against the battery weight.  This is why small power systems will be very low endurance for a long time in my opinion.

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52 minutes ago, kasper said:

Just think

- Eflyer has 110kw motor,

- guessing it uses 30-40kw to fly at endurance

- they claim 3hrs endurance

- they need around 90-120kwh of battery

- LIFEPO4 systems weigh 6kw/kwh

This would imply a battery pack of around 540-720kg

That is not believable.

 

Hi Kasper, you know what your talking about, your numbers are close!

they claim a 92kWh battery pack, with a mass of 353kg.

eFlyer

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18 minutes ago, RossK said:

Hi Kasper, you know what your talking about, your numbers are close!

they claim a 92kWh battery pack, with a mass of 353kg.

eFlyer

Yes BUT they are not being fully honest ... 353 kg is the bare mass of the cells themselves not the weight of the assembles battery packs. 

 

There will be additional weight in the airframe that is required to assemble a useful battery pack even an air cooled system like the Ducati or my system.

 

The thing that was interesting to me in the linked youtube video was the clear discussion of how a battery capacity more closely matched to the draw is supportive of an aircooled/low weight battery pack compared to high draw packs that really will need liquid/active cooling etc.

 

It was one of the reasons I chose a relatively large capacity battery pack as a starter for the airframe install system ... I ran a test setup of the motor on a small capacity test battery pack and was not impressed with how quickly and how hot the pack got ... and even less happy with having cooked a new battery pack so badly it was scrap.

Edited by kasper
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