How far are we from the perfect electric "homebuilt" ?

Discussion in 'Hangar Flying' started by Speedboat100, Aug 20, 2019.

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  1. Aug 26, 2019 #141

    stanislavz

    stanislavz

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    It basic glider, used for studens. The Designer had a long line of them in many shapes. But they are calculated for max 70kg pilot. And have rather poor glide ratio. Here you have full list of his constructions. Columns translation ( yours is bro-18):

    Name, targed/category, year, wingspan, wing area, lengh, empty weight, glide ratio, minum descending ? , minimum descending speed, how many builded, whom build it.

    [​IMG]
     
  2. Aug 26, 2019 #142

    Speedboat100

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    Last edited: Aug 26, 2019
  3. Aug 26, 2019 #143

    12notes

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    I did no such thing. That video is complete and utter crap.

    You've shunned the opinion of many experienced engineers on here already, people who have actually accomplished things with real aircraft, and somehow you think a video of an inexperienced, just-started-university, student building an aircraft that has never flown is proof everyone else is wrong? Particularly one whose frame is poorly stick welded out of galvanized pipe that he's planning on covering with fiberglass? Built in contravention to pretty much every material guideline and building standard for aircraft out there? With a main spar behind the center of lift, and a front spar that's not attached to the fuselage at all? That wasn't designed, that was kludged together based on what an airplane looks like. No engineer would build, approve, or get anywhere near anything like this. That is a suicide machine, not an aircraft.

    Also, it fails to mention ANYTHING related to any of your arguments. Not that it would've helped if it did, the person in the video, while enthusiastic, does not know anything about aviation design.

    Seriously, get a clue. You don't know anything about aircraft at all if you think this video is how aircraft design or construction is done. Your opinions are completely uninformed, and worse, you refuse to learn to correct them, but are extremely vocal in regurgitating these incorrect opinions here. Stop making this board worse.
     
  4. Aug 26, 2019 #144

    Speedboat100

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    Is the designer still alive ? Is there any way to get to know what he was after with that wing solution ?
     
  5. Aug 26, 2019 #145

    Speedboat100

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    If I sum it up...I have designed pair of floats that are 10 kg together. Here we see that before innovation of some seriously light materials...gliders were even 35 kilos empty. We now can easily squeeze 10 kilos of one..so we have 25 kg air frame with 10 kg floats. That makes 35 kg...we load engines in it...lets say 3 kg worth electric ones..we still have 32 kg left for batteries and we hit 70 kilos...empty. Ok..let's be reasonable 2 kilos for struts, propeler and mounts etc. 30 kg left for batteries. If we have semiclosed cockpit and glideratio 1:20..it cruises at 2 kw.

    Ok I counted using Tesla batteries that it ought to cruise 2 hr 36 minutes with 30 kilos of batteries. Possibly the pilot ought to be under 80 kg to reach this..250 lbs dude may only fly 1 hr 30 minutes.

    This is my target !
     
  6. Aug 26, 2019 #146

    Tiger Tim

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    It sounds like what you need is a gofundme or a Patreon account if you’re just building an airplane for yourself.
     
  7. Aug 26, 2019 #147

    Speedboat100

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    Yes good idea Tim. I am also developing a pitch controlled H-darrieus wind turbine (3rd proto)....and it seems I am getting a big back up for that project....and small plane like this is created with just vapour of the money that goes to a real 4th test model of the turbine.
     
  8. Aug 26, 2019 #148

    Speedboat100

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    Ok...I try to behave. I am slightly ADHD so I cannot always absorb everything everybody is saying...ok ?!
     
  9. Aug 26, 2019 #149

    stanislavz

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    Nope. RIP [​IMG]

    But his ideas of basic gliders will live long.

    Anyway - from my point, it is not bedt frame for conversion. Please look better at Rutan designs. Like global flyer etc...

    Just long wing span, load distributed across wing span..
     
  10. Aug 26, 2019 #150

    Speedboat100

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    Bronius Oskinis is my hero R.I.P. !

    I understand the long span efficiency...but I kinda think Bronius was a master of low cost fun for everybody kinda thinking in aviation.
     
  11. Aug 26, 2019 #151

    stanislavz

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    Not only. Cheap and mass produced by local group of kids to make first step in aviation.

    But back to topic - you really are forced to have glide ratio of 15 at least, and high payload ratio. And if not carbon spar - then wooden flying wing, like kasperwing or similar, loaded with you at the center of wingspan, and batteries on wing tips...
     
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  12. Aug 26, 2019 #152

    litespeed

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    The abomination aircraft is well known down here in Australia.

    It was never going to fly nor did he really expect it to.
    The young bloke was a refugee and wanted to have a go building and have some fun. He desperately wanted to learn how to fly.

    The local flyers organised free lessons for him and and he infected them with his enthusiasm.
    At this stage I expect he has his wings and probably at uni.
     
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  13. Aug 26, 2019 #153

    Speedboat100

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    Yes...I have to have something here..it is a bit secret. By making it really lite like Bronius...I can achieve pretty good glide ratio with wings that are now only spanning 6.3 meters...I am considering fixed slats...but there is something else too. I have to make a 1/3 scale model to see the efficiency that I am after...and definitely 2 electric engines..if not 4.

    I have been rehearsing this now for 12 years.

    My themes have been.

    1. Ground effect
    2. Low drag
    3. Lite weight
    4. High lift ( and lite ) wing
    5. Very cheap to make ( which is relative )

    I think I can fit inside..at my 6 ft 3 in torso. Still the plane is with floats is only 3.8 m long and 3.4 m without them on nose wheel configuration.

    It has got aggressive looking twin rudders ( but one boom ).
     
  14. Aug 26, 2019 #154

    Speedboat100

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    I have been thinking about that kid...all the things he has been through..it may not be the easiest thing to start building high performance aeroplanes right away.

    He possibly never went through the rubberband => r/c control phase in his life.
     
  15. Aug 26, 2019 #155

    stanislavz

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    I am getting old, and not believe in 6.5 span.. 2 and 4 are mutual exclusive, 3 - i'd better lost 30 minutes of flight, than 1 g from rated load :)

    It is good idea to try model !
     
  16. Aug 27, 2019 #156

    Speedboat100

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    One thing I have tried in 100s of my sketches to seek is the lift also from the fuselage...and this time I assume I did hit the jackpot....it gives 20 ( 25% ) % more lift to the thing in flight and 30% at take off. So 6.5 m is not bad....as they remain light....and flutter free.
     
  17. Aug 27, 2019 #157

    henryk

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    -see BKB1-A story =low cost, tailless club class glider...

    AR=10 , L/D= 30 !

    + super aerobatic possibility (ultralow radius !!!) =

     
  18. Aug 27, 2019 #158

    Speedboat100

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    Since I have morized aeroplane with tapered wings the calculations for performance are a bit difficult.

    First and foremost I am concentrated on the range more than flying time as I want to go somewhere.

    So my plane has to cruise slightly faster than the part 103 planes top speed is...yet is has to land safely at very low speed..this is a demanding task...with limited power.

    https://www.fzt.haw-hamburg.de/pers/Scholz/OPerA/OPerA_PUB_DLRK_12-09-10.pdf
     
    Last edited: Aug 27, 2019
  19. Aug 27, 2019 #159

    stanislavz

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    Ok, i will put your on the ground, but it was done before.

    https://en.wikipedia.org/wiki/Westland_Dreadnought

    Or this one https://www.secretprojects.co.uk/threads/lisichkin-rentel-lk-1-niai-1-«-fanera-2-».19416/

    [​IMG]

    Later one is more interesting as comparison base, because it used same as Po-2 biplane (empty/max 770/1030) and sh-2 flying boat (680/970). And have highest speed and empty max weight with of 652/1160kg..
     
  20. Aug 27, 2019 #160

    Speedboat100

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    Yes here lies the answer. How to arrange the pods you talk about...wing and the fuselage in a very compact single seat electric aeroplane with SEVERAL engines. I can also assure you I do not have anything like Burnelli or any other lifting body engineer had in the past on my design..it is compact and attractive..in a very modest way like in BrO-18.
     
    Last edited: Aug 27, 2019

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