f5soh

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #120 on: July 22, 2017, 09:51:15 am »
The only videos with the real one only show hovering or i didn't found a video while doing cruise flight...

Do you find the stall speed according to the wing area you have in your Rc model ?

zipray

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #121 on: July 22, 2017, 10:31:58 am »
The biggest characteristic of this structure is stepless Smooth transition。Because of the existence of half a rotated flight mode。

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #122 on: July 23, 2017, 02:41:15 pm »
Great to see you back Zipray :)
Yes, get those tilt rotors in there and it will be amazing to see what will happen.
I do know the other successful amazing builds you made before, so keep it up, and show the way :)

zipray

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #123 on: July 23, 2017, 05:45:17 pm »
karla,glad to meet you.Are you still in Beijing?Because  the problem of  network and language I don't often come here,But I'm willing to share with you my findings.Some of fluid mechanics and flight control parameters of the specific issues I can only express clearly in my native language,Maybe your Chinese level be better than me.First of all, you need to do a bicoper,then let it along the CG rotated and Consistently maintain the CG same as the wings.It should be pointed out that tilt rotor shaft and thrust vector is not the same thing.

(modified by cliff to change it to youtube.com for better viewing)
« Last Edit: July 25, 2017, 04:37:56 pm by TheOtherCliff »

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #124 on: July 24, 2017, 06:38:32 am »
Yes, still in BJ. Thanks for sharing the video Zipray.
No need to explain, just good inspiration to see your builds.
That looks like a bi-copter with setup to use the gyroscopic forces to assist stabilization and control, an OAT (oblique angle tilt).

Do you intend to put that in and combine it with a fixed wing frame later on?
That would be interesting.
I have not seen anyone do that yet.
I considered it for a while, but could not figure out how to do it and put it aside.

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #125 on: July 25, 2017, 03:57:11 am »
... I guess if you add another motor dedicated for forward flight when using the wings, then it will work similar to video by f5soh some posts back (multi rotor + fixed wing). But making the same OAT rotors (have 450 angle) change in to some thrust vector style for forward flight, might be doable but require some complex mechanic solution?

zipray

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #126 on: July 25, 2017, 02:17:29 pm »
Yes, use a single forward motor is a simple solution.However,The plane was inspired by the Augusta westland ProjectZero.Prototype aircraft using variable cycle/collective pitch.And I think the OAT bicopter can replace it.Doing so requires complex CFD analysis and airfoil design.In fact,you can be understood as the wings rotate relative to the OAT Bicopter.


« Last Edit: July 25, 2017, 05:01:50 pm by TheOtherCliff »

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #127 on: July 25, 2017, 04:45:13 pm »
karla,glad to meet you.Are you still in Beijing?Because  the problem of  network and language I don't often come here,But I'm willing to share with you my findings.Some of fluid mechanics and flight control parameters of the specific issues I can only express clearly in my native language,Maybe your Chinese level be better than me.First of all, you need to do a bicoper,then let it along the CG rotated and Consistently maintain the CG same as the wings.It should be pointed out that tilt rotor shaft and thrust vector is not the same thing.

(modified by cliff to change it to youtube.com for better viewing)

Is OAT just a bicopter with the motor tilt set to something besides straight forward/backward?  It looks like it works well.  Do you have a link to description of OAT; why to use OAT?

I have wondered why I haven't seen much about bicopter having a minimal roll control just needing some yaw mixed in.
« Last Edit: July 25, 2017, 04:59:26 pm by TheOtherCliff »

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #128 on: July 26, 2017, 02:35:27 am »
Here is one description how to set it up
http://wiki.openpilot.cc/bicopter-hardware-setup.html

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #129 on: July 27, 2017, 04:42:25 am »
...And I think the OAT bicopter can replace it.Doing so requires complex CFD analysis and airfoil design. In fact, you can be understood as the wings rotate relative to the OAT Bicopter.

Fascinating Zipray. Good luck, will be great to hear your progress on it!

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #130 on: July 27, 2017, 03:42:23 pm »
So glad to finally be able to fly this thing rather than just do endless soldering jobs:)



The first lift off is without the front dome to keep the CG just above the wing spar.
I want to test the most likely configuration that will work in hover mode. And it did  :D

Then, the second lift off I wanted to try how to hover when being prepared for forward flight, its with the dome on and that moves the CG to a more forward position so when the I tilt the rotors to forward flight mode, then CG will move to  just above the Center of lift of the wings. About 2 cm forward.
It turned out it is a bit heavier to maneuver but it does work.

So all in all, pretty good state for taking next step and try turning the nob to make the rotors tilt forward.
That will be next test flight.

BTW I am flying in Attitude mode with complimentary stabilization, but the magnets show very green always so I have good hopes to do position hold etc in Hover mode when changing to ins13 mode.
« Last Edit: July 28, 2017, 07:23:41 am by karla »

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #131 on: July 27, 2017, 06:58:09 pm »
Very interesting!

Now I want one.  Impatiently waiting for forward transition and forward flight.  :)

FYI: I have recently built a fixed wing with Revo and GPS/mag.  I found that the mags on it can be affected when sensor is is 20cm from cowl hold down magnets and 30cm seems about safe.  I watched mag scope while moving a the fuselage/cowl magnets around the sensor to see what is OK or bad.  I also see that my lipo alarm (with little magnet speakers) needs to be over 20cm away from sensor too.

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #132 on: July 28, 2017, 07:14:23 am »
Haha, yes really!
The estimated stall speed for the wing is around 30 km/h, its pretty fast, so I think I need a larger field to try it out, there are too many high trees close by.

I am glad you mentioned about the magnet lock down can affect the Mag/GPS-sensor!
Been thinking of that and got strange results like the onboard mag is more accurate than the external one on the wing (should be the other way around). I will check these mag-lock things - 30cm is a lot.

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #133 on: July 29, 2017, 09:46:33 am »
Hope to find a better flying field tomorrow Sunday,
meanwhile relocated the GPS to avoid most disturbances, far out on the right wing side.



It looks like a ublox gps but its just the cover case, inside is the OP GPS, I do not have another cover case.

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #134 on: July 29, 2017, 12:46:31 pm »
Did you know that linear antennas like your 433 antenna on the left side have a "null" off of each tip so that the way you have it mounted you will have very little connection when the nose or tail is pointed at you (and it is a long way away).

433 is a pain because of the large antennas.

Standard procedure mounts linear antennas vertically to reduce this problem to only happening when you bank steeply.

The turnstyle/turnstile antenna is a controversial antenna to try to avoid this issue.