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Ornithopter challenge

3,875 Quercon  9 months ago
109 downloads

Deadline: 15 April

PLEASE READ DESCRIPTION, IMPORTANT TECHNICAL INFO HERE!

Hello, as you might have expected ornithopter challenge is out. Here i gave you a set of 8 wings with all software necessary to make them flap in the exact way they need in order to generate lift.
IMPORTANT:
If you want to modify wings in any way that changes their weight or shape, you must read technical description.

Technical description:

General remarks:
The wings are only producing upwards thrust, if you want to have a source of forward thrust, you need use normal engines.

Recommended wing loading is below 100kg/m² (20.5 lb/ft²)

Wings edition

Basic

Inside the variable editor you can find 4 variables on the very top that let you change various parameters of the wings, as shown on the image below:

wingTravel controls how wide the movement range of the wings is, this also affects how much lift is generated: more range = more lift.

staticSpread controls how much wings are separated from one another when wings arent flapping (a.k.a. airplane mode), useful primarily for esthetics

dynamicSpread controls how much additional separation wings gain when they start flapping (useful for preventing them from hitting each other).

frequencyCorrection can only be used when editing wing shape or mass, more on that in a second.

Advanced

Warious wings have different optimal flapping frequencies (meaning amount of times they flap per time unit). If wing is flapping at its optimal frequency, it can produce most lift from this motion.

The exact value of this frequency depends on wings mass, length and shape, and its a very complex relation, so sadly i cannot give you a ready equation for it. However the general rule is that bigger wings flap slower, and smaller wings flap faster.

frequencyCorrection is the variable that will allow you to change your wings flapping frequency. If you want to change the shape of the wings (which i very much encourage you to do), you will also need to fine-tune it untill you find the right value. Easiest way to do that is to set value of the frequencyCorrection variable to Throttle in variables editor, as on the image:

Now when you turn on the wings you can find the optimal frequency just by sliding your throttle up and down. When you are done just convert the % value of your Throttle input into a number from 0 to 1, and put it back into frequencyCorrection variable.
For example 85% Throttle converts to 0.85
or 43% converts to 0.43, and so on.

Also important note is, that the wings with higher frequencies do better yawing.

Challenge rules

Only requirement is that the main device to produce vertical thrust on the craft has to be the set of wings i gave you.

I also heavily discourage using gyros.

Troubleshooting

If wing movement induces gradually growing left and right fuselage oscilations, it means that wings move at resonant frequency of the fuselage. To fix it you need to change the frequencyCorrection to a value for which the issue does no longer occur, usualy it means decreasing it. (Sometimes changes as small as 0.005 are enough - and sometimes not.)

When roll is inverted and aircraft acts weird, it means that your frequencyCorrenction is set way too high.

Good luck, have fun!

See ya

Spotlights

General Characteristics

  • Created On Android
  • Wingspan 83.8ft (25.5m)
  • Length 21.0ft (6.4m)
  • Height 5.5ft (1.7m)
  • Empty Weight 30lbs (13kg)
  • Loaded Weight 30lbs (13kg)

Performance

  • Wing Loading N/A
  • Wing Area 0.0ft2 (0.0m2)
  • Drag Points 736

Parts

  • Number of Parts 4
  • Control Surfaces 0
  • Performance Cost 145
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  • Profile image
    3,875 Quercon

    If any issues arise, please comment about it, i will put them in the troubleshooting section in the post.

    Pinned 9 months ago
  • Profile image
    27.1k ToeTips

    @Quercon
    Dragon Flies are hard to make. Cool, but difficult.

    6 months ago
  • Profile image
    3,875 Quercon

    Seems like this project turned out to be a bit too complex

    7 months ago
  • Profile image

    Wow, I’m gonna say this I can’t build but I really want to see everyone’s creations

    9 months ago
  • Profile image
    3,875 Quercon

    @KenzarAircraft Well funny thing is: i didnt. Didnt even know this channel

    9 months ago
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    10.8k Kenzar

    you watched the found and explained video, did'nt you?

    9 months ago
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    3,875 Quercon

    @Hahahahaahahshs Oh yeah, thats a sign that your frequency is way too high for those wings

    9 months ago
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    6,419 dabestsock

    @Quercon that's funny

    9 months ago
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    @Quercon yes when I put frequencycorrection up it made it so that my roll is inverted when I did nothing to the roll

    9 months ago
  • Profile image
    3,875 Quercon

    @dabestsock Its a wild coincidence, i learned about this channel first time through other people talking about it in this exact comment section, lol

    +1 9 months ago
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    6,419 dabestsock

    @Quercon you a Found And Explained fan or this a coincidence

    9 months ago
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    31.1k TunderTunder

    Cooomee, geeet your dineeeeeeeeEr!

    9 months ago
  • Profile image
    3,875 Quercon

    @OkaNieba Yes, no problem, just read the description, as you may need it if you want to adjust the wings to your heli fuselage.
    Also no problem if you publish it, as long as you give credit.

    +1 9 months ago
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    Damn, Cool Orni Mechanism !

    Btw May I Borrow This System (For Experiment Only, Not As Challange Submision) ? I Want To Test By Slapping It Into My Heli Fuselage

    9 months ago
  • Profile image
    3,875 Quercon

    @Hahahahaahahshs Did any more significant problems arise?

    9 months ago
  • Profile image
    3,875 Quercon

    @Hahahahaahahshs you need to find it out yourself, i recommend hooking up throttle to it, as in instructions

    9 months ago
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    @Quercon so yeah that’s the problem other than the wings don’t hit each other but the problem is if I need to decrease or increase it

    9 months ago
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    3,875 Quercon

    @Hahahahaahahshs depends what kind of shake you mean, if its shake of fuselage from wing flapping alone that starts small, and gradually increases into wobbling left and right untill wings hit each other, then it means that your wing frequency matches the resonant frequency of the fuselage you built. To fix that you just need to tune frequencyCorrection to a different value. (Sometimes its a difference of just 0.005, sometimes it needs to be more significant.)

    9 months ago
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    @Quercon Question how do I make the damn thing be able to not shake

    9 months ago
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    3,875 Quercon

    Decription updated

    9 months ago
  • Profile image
    3,875 Quercon

    @STENDEC if you download this craft, you will get the set of wings you need to use for this challenge

    9 months ago
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    3,875 Quercon

    @Noname918181 Good point, when making this thing, the challenge aspect was the thing i forgot, lol. I guess something standard like spotlights and upvotes for various places, but im unsure how i will judge yet, guess i will take a look at other challenges, and draw some inspiration. I also plan to mention and reward all crafts distinctive in some way or another (which would be not so easy task i imagine, as ornithopters are distinctive in and of itself).

    +1 9 months ago
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    3,875 Quercon

    @EnglishGarden You can, but you dont need to, if you follow the instructions, you can change the size without the need for xml scaling it, and also i am not sure if xml scaling wont change wings in a way that would change their frequency. So i encourage you to change the wings in an usual fashion. (You can change the size of the control bases without consequences though)

    9 months ago
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    @xYoshii_ bro same

    9 months ago
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    I've read the description, it's nice, and helps a lot especially for those who are not very experienced in making these things, but it seems it's a bit lacking on information about the challenge itself
    .
    What are the rules? How will you judge the participants? Prizes?

    9 months ago
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