Electric power for dummys......

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Grumpy Cynic
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I watched 1/4 of the 1st one and was very unimpressed by his knowledge.
I got the impression he was just dumbing down the video for general consumption. The rest of it didn't provide any more insight for those of us that have been researching this topic for a while.
 

Riggerrob

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What many owner/pilots want to know is which motor/controller/battery combination is compatible with their airplane when the current VW, Rotax, Continental engine quits.
Most of the first production batches will be electric retrofits to existing airframes ..... the same way that the new electric racers are based on Goodyear/Formula One airframes.
 

pictsidhe

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What many owner/pilots want to know is which motor/controller/battery combination is compatible with their airplane when the current VW, Rotax, Continental engine quits.
Most of the first production batches will be electric retrofits to existing airframes ..... the same way that the new electric racers are based on Goodyear/Formula One airframes.
Unfortunately, electric isn't yet suitable for powering draggy aircraft.
 

proppastie

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What many owner/pilots want to know is which motor/controller/battery combination is compatible with their airplane when the current VW, Rotax, Continental engine quits.
Most of the first production batches will be electric retrofits to existing airframes ..... the same way that the new electric racers are based on Goodyear/Formula One airframes.
I would think given the experience level with this new technology some of those electric installation will be quitting also. Is there anyone selling a proven whole system for our aircraft sizes.....and it seems like everybody wants a different capacity, or weight or power.....which makes marketing a complete "proven" system somewhat difficult.
 

pictsidhe

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A system to replace a 100hp engine just isn't possible without an extremely heavy battery or a very short run time. The batteries are just not there yet. So no, there are no drop in IC replacement systems and won't be for many years. If you want an electric aircraft today that won't make you a laughing stock, you must use a low drag airframe. Think motorglider, or wait another 10-20 years.

Numbers are always good to get the point across:

A pretty good (and very expensive) 1000lb battery could supply 60hp for one hour.

You can wait decades until batteries are way lighter for your aircraft designed around an IC engine, or work with you can get today. Purists may howl. But personally, I like the idea of a hybrid to provide a bit of extra oomph for a few minutes of takeoff and initial climb power.
 

Steve C

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You are spot on. I'm not even sure the Formula electric guys realize how much the battery is going to weigh. It's going to need about 300lbs by my estimate. That's not a huge problem for a new design, all carbon airframe, but for a retrofit that's tough to deal with. You'd just about have to put them in the wing for structural reasons, but for cg that's too far back.
 

autopilot

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I,m new to this thread, but some of you already know me from roadable aircrafr (note the spelling!). Perhaps some of you should download the owners manual from EMRAX. I made inquiries to several manfctrs and only Emrax responded and with info that is understandable and usable (I can repost to anyone who's interested.
Their motors are light and compact from 15Kw to 200. they are "stackable" and can also be used as generators (but you do need a power source for that)
I am investigating a hybrid system for my project and am currently waiting on confirmation of my figures.
My proposal is to use twin (not stacked) 288HVCC motors (50Kw and about 20kg cooled each) each continuous) connected through the (minimal) battery pck to possibly another of the 288 range or the 268LVAC (20kg) for electrical, continuous generation.
I am a novice at this and will let you know how wrong/right I am when I have a response from EMRAX.
As I've blown my weight target anyway I've just added more power and WA
 

BJC

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I am a novice at this and will let you know how wrong/right I am when I have a response from EMRAX.
As I've blown my weight target anyway I've just added more power and WA
If your initial weight target was close to reasonable, I encourage you to stick with it through another design iteration. Find a way to achieve your design objectives before giving up and adding mass.

Designing a good airplane is difficult. Designing a low mass car is difficult. Designing an electric energy source light enough and robust enough for flight is difficult. Designing a hybrid energy system is difficult. Combining all of those things into one reasonably performing system has never been done. You have undertaken a very complicated design build and test project. I wish you success.


BJC
 

autopilot

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A "low mass" car built as a "home-built" is not difficult for me, it's time consuming. Elec energy systems are robust enough, I'm NOT being 'Green" so I don't need 200Kg+ of batteries. My "car" already has an engine come generator.
Getting the whole thing to fly is only a matter of power and lift. The hard part is making it handle and perform well.
 
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BJC

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A "low mass" car built as a "home-built" is not difficult for me, it's time consuming. Elec energy systems are robust enough, I'm NOT being 'Green" so I don't need 200Kg+ of batteries. My "car" already has an engine come generator.
Getting the whole thing to fly is only a matter of power and lift. The hard part is making it handle and perform well.
Well that is good. When will you post some videos of it flying and driving?


BJC
 

autopilot

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At the risk of being wrong again, I hope to make a "full-size" start early in the new year. But I have said this before!
I will be using a Smart Roadster at this stage (time constraints), not the body you opposite, but using the same "flying apparatus". See roadable aircrafr
watch the spelling
.
The same applies to finishing and flying the model you see opposite.
 

autopilot

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I just heard back from EMRAX and they have confirmed (per side) 50kw/120Nm @4000rpm requiring 500V @ 115A.
These motors cost from Eu 2700 -3700. Now all I need is for them to confirm the generator motor size and specs.
 
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