Flea style "Piojo Flying MiniBike"

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by FritzW, Oct 26, 2015.

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  1. Aug 24, 2019 #361

    Victor Bravo

    Victor Bravo

    Victor Bravo

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    My vote is that the Piojo, if and when it becomes a real project, is absolutely the right candidate for tab and slot construction (if it has to be built in wood). And no round, laminated, or complicated "fiddly bits" should be necessary whatsoever. If a builder wants to add rounded laminated tip bows, and a leather stitched interior, then he or she can do that, but it's totally optional. A Piojo airframe should be able to be put together in a month or so using T-88 glue, and using Oratex the covering would take about a weekend. Another month MAX of engine mounting, misc. systems and control runs, fuel tank,etc. and you should be able to start taxi testing.
     
  2. Aug 24, 2019 #362

    FritzW

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    I'm still confused by the flea wing vs. free wing. So a free wing doesn't have, or need, any control? It's just free to pivot and find it's own "happy place" AoA? And the split Spraat wing is a free wing that's split on the center line and has independent pitch controls?

    If you can control a free wing why don't they use them on fleas so you don't have to hold back pressure on the stick all the time?
     
  3. Aug 24, 2019 #363

    Victor Bravo

    Victor Bravo

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    You have to hold back pressure on the stick in a Flea at all times??? That would geet old pretty fast, speaking only for myself.
     
  4. Aug 24, 2019 #364

    FritzW

    FritzW

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    I saw it on a youtube video so it has to be true.
     
  5. Aug 24, 2019 #365

    erkki67

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    I can’t follow you, I’ve been flying with a Balerit, the HM1000, hands off.

    Power on and up it goes, power down and down it goes, with the wheel or stick you only ctl the speed.
     
  6. Aug 24, 2019 #366

    Tiger Tim

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    I guess logically it makes sense that on early fleas you must have had to hold a little back pressure at all times. Henri just had a single cable on the HM.14 controlling incidence and something had to have held it taut (there was no return cable, no spring, and no counterweight). At some point the plans changed this cable to a rod and all fleas thereafter used rods which makes it harder to tell when, if at all, this need for constant back pressure went away.
     
  7. Aug 24, 2019 #367

    FritzW

    FritzW

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    For some reason back in 2017 (on this thread) I knew that all fleas except the HM-1100 needed back pressure on the stick all the time. (it's a short thread with some good info, it's worth thumbing through)


    From post #46 on that thread:
    "The HM-1100 is the only "per the plans" flea that I'm aware of, that doesn't need back pressure on the stick. The wing was designed from the beginning to be controlled with tabs and there's no direct control linkage."
     
  8. Aug 24, 2019 #368

    erkki67

    erkki67

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    In fact, the Corduan or HM1100 had a Freewing controlled only by tabs.

    The HM1000, the Balerit had pushrods like almost all the fleas before.

    The first HM14 had only cables to control the incidence of the fwd wing, this feature and the overlapping caused in flight flip overs, which where not recoverable due to the cable control of the fwd wing.

    After the mod with separated wings and a new airfoil and pushrods instead of cables healed the bad habits of the Flea.

    Backpressure is only needed to achieve a certain airspeed, with all the fleas, except the HM1100.

    So a Piojo with split fwd wings would give it the cross wind capability and most probably, one of the safest little 3-axis flyer.
     
  9. Aug 24, 2019 #369

    Sockmonkey

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    Does it need all three though? Fixed tailfins still leave it with pitch and roll control via the fore wing, which is enough and eliminates the control runs.
     
  10. Aug 25, 2019 #370

    plncraze

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    Sounds like a Spratt Piojo with split wings.
     
  11. Aug 25, 2019 #371

    FritzW

    FritzW

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    I don't think it's a question of "need", it's purely a "want". Ercoups fly fine, I just think they'd be a lot more fun with 3 axis control.
     
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  12. Aug 25, 2019 #372

    FritzW

    FritzW

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    Is the hassle of splitting the wing less than the hassle of putting ailerons on the back wing? Would the split wing be positive control (linkages) or controlled with servo tabs? (maybe Bowden cables).
     
  13. Aug 25, 2019 #373

    Hot Wings

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    Here is the Spratt patent. Looks pretty simple to me:
     

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  14. Aug 25, 2019 #374

    FritzW

    FritzW

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    Compared to a regular 'ol aileron setup?
    Spraat.jpg


    And the wing pivot relying on the threads of two rod end bearings screwing in and out every time you move the stick. ...I dunno
    Spraat2.jpg
     
    Last edited: Aug 25, 2019
  15. Aug 25, 2019 #375

    plncraze

    plncraze

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    The plans for the Spratt Controlwing are free on the internet. There are quite a few parts on it that you really don't want to fail. Even the Fleas have some "Jesus bolts."
     
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  16. Aug 25, 2019 #376

    Hot Wings

    Hot Wings

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    Yeah, that does 'look' more complicated but it is combining a V-tail style mixer with pitch and trim all in one mechanism. Separate out the needed functions and it looks simpler. But the part count may actually go up?
     
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  17. Aug 25, 2019 #377

    Sockmonkey

    Sockmonkey

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    The wing doesn't have to do three axis.
    Pitch and roll is fine.
    Look here.
    [​IMG]
    Most fleas have two rods controlling the fore wing so splitting it doesn't mean adding another rod.
    The Horten elevon setup would work fine for this.
    [​IMG]
     
  18. Aug 25, 2019 #378
  19. Aug 25, 2019 #379

    Speedboat100

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  20. Aug 25, 2019 #380

    FritzW

    FritzW

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    And here's a recipe for banana nut bread. What does that have to do with the Piojo?
     
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