A really (too?) small & light micro-bipe STOL project (hybrid maybe)

Discussion in 'The light stuff area' started by Xanadrone, May 26, 2017.

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  1. May 26, 2017 #1

    Xanadrone

    Xanadrone

    Xanadrone

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    Just a few words for now: I tried to imagine an even smaller Cri-Cri, in biplane form (Mitja would say... topspeedish-small at just 9 ft. 6 in. long), but also less complex, expensive and time-consuming to build.

    ...Woud it fly though, despite its span of 16 ft.? And how good? - This would be the major point of debate, being a real theoretical nightmare at a first glance (prone position of the pilot, sesquiplane, inverted V-tail... or sort of, electric and/or IC-propulsion etc. etc.)

    P.S: The pilot in the scale-image is... sort of me also, being 30 years younger and - more important - 30 lbs lighter :gig: than the actual Me.

    DSCF1353.jpg
     
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  2. May 26, 2017 #2

    cluttonfred

    cluttonfred

    cluttonfred

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    It's a neat concept, but you are right that it's a lot more complex than it needs to be. At first glance I'd say the wingtip "feathers" are unnecessary and the "reverse tricycle" landing gear would be very short-coupled and twitchy on the ground. You might want to check out the Hovey Whing Ding, not as an actual project tackle since it has a reputation as a fairly complex build despite the size, but for some idea that are proven to work. A simpler design inspired by the Hovey Wing ding with a modern paramotor engine and your twin tails might work well.

    hovey-wing-ding.jpg
     
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  3. May 26, 2017 #3

    vtul

    vtul

    vtul

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    Wonderful drawing!
     
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  4. May 27, 2017 #4

    deskpilot

    deskpilot

    deskpilot

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    Hi Axandrone, I'd like to see top and front on views, if you have them. BTW, do you really have a hook hand, if so, how do you have permission to fly?
     
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  5. May 29, 2017 #5

    Xanadrone

    Xanadrone

    Xanadrone

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    First of all thanks for your input! I was initially tempted to post this idea in the Motorcycle Of The Air thread, or Flying With 14 HP (only in level flight though), or, or..., but I thought finally that it deserved a separate topic, because it includes some new and combined solutions serving the main interest of it - and the point of start for me: to maximize the... minimalising simplicity and affordability of the flight for a single guy (it can be married also, but some would say not.) :grin:
    More seriously speaking, this micro-bipe is intended to be a ludic (and cheap to build) object and not an utilitarian flying device - baptizable as an air-toy methinks, so I am waiting also for some possible name proposals from you, my already imaginated names being a bit too laughable for now - thats why I do not mention them.

    Anyway, until refining the other 2 views of my micro-bipe Ride-And-Glide project (it might take a couple of weeks), it is necessary to clarify some basic details to correct a few explainable confusions:

    - The landing gear would be a classic tail-dragger and not inverted, with two fully shock-absorbed 25 cm (10 inches) main wheels fixed on the lower wing (1 foot 4 inches chord, 10 feet span); just the little bit advanced position of the lamellar spring suspended tailwheel is somehow peculiar, because...
    - ...the ampenage IS an inverted V-tail, but a non-classic one whilst supported by two small oblique pseudo-stabilizers - a more draggy solution for sure, but the only feasible keeping in mind the... 2D fuselage (with a saddle - do not forget the prone position) and its original (I guess) and very simple command by feet, without any mixer.
    - Those strakes of the upper wing (2 feet chord, 16 feet span) seem to be a good solution for STOL-style flight, since a number of old and not so well-known studies claim to reduce the L/D at high AoAs and also increase the stall limit; claims that I’ve got to verify on a 1/2 scale model though - yes, 1/2 whilst the real airplane would be tiny enough to allow such a good scale-ability.

    Oh, and that hook of the scale-pilot in the drawing is just a graphic joke ...with the secondary purpose of a readers’ attention check - congrats for discoverig it!

    Many other details must be revealed anyway (including the type of materials intended to be used - it would be mainly wood/ply for the sake of affordability - some better suggestions?), so I will deliver them to you in some other not-too-long-to-be-boring posts.
     
  6. May 30, 2017 #6

    Xanadrone

    Xanadrone

    Xanadrone

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    A simple (and just preliminary) napkin-sketch would be more clarifying than words about its inverted V-tail and landing gear:
    DSCF1374.jpg

    A few other details: this hybrid version with permanent IC-engines propulsion and e-motors used only for climb / take off is only one of three possible variants, that could be also:
    - either pure electric -- maybe with a more glider-style span and A/R, lets say 19-20 ft for the 2 ft chord
    - or only IC-motorized; this one could be lighter without the batteries and with greater... but riskier autonomy, implying also another position of the wings (further backwards). The STOL-favorising effect of the four small e-motors placed ahead the upper wing would dissapear too.
    A Screamer Veloce ;) 50 HP two-stroker could be tempting though.

    The hybrid and/or electric versions have the implicit advantage of an advanced CG/CP by positioning the relatively heavy batteries upfront, thus resulting a not so short-coupled geometry for such a tiny air-toy.
    Second advantage: the possibility to optimise the permanent functioning IC-propellers for cruise (level flight) and those folding e-props for climb (lower pitch.)

    Please correct me if I am wrong - even like a friend of mine (he IS funny, albeit being an aerospace engineer) that asked me if I did not choose these micro-dimensions by lacking A3-format millimetric paper. :gig:
     

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