f5soh

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #15 on: April 23, 2017, 08:53:20 pm »
Double check your power source...

You can try using a simple 1S battery fully charged as power source

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #16 on: April 24, 2017, 03:27:11 am »
Thanks Laurent.
Issue solved.
I am pretty sure it was the fancy Align Heli servos consuming too much energy.
When having just a small battery dc 5 volt in, I could connect only one servo in addition to the motors without the FC rebooting. Using a 3s LiPo could have 3 servos okay but not 4. Then I replaced 2 of the Align servos to some old 9 gram simple servos and now all 4 plus motors and gps works without any rebooting. I happen to have 4 of these old but new servos around being idle so they will do for this project.
Karl

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #17 on: April 26, 2017, 04:28:26 pm »
Moving on to next challenge.

So having the motors and servos set up the way I want and confirmed they move correctly with the TX controls as well as moving correctly when the FC is trying maintain attitude, How to fasten the tilt rotors at the end of each wing tip?

Since I already have the Mako fixed wing (https://www.readymaderc.com/store/index.php?main_page=index&cPath=112_409_649 ) and like a lot the way it flies ( )
I thought to modify that frame but I did some research to find if other fixed wings are out there that might be even more suitable. However, I really did not find anything outstanding so decided to go ahead with Mako.
The picture attached show the standard design of the wings with a Wing Spar enforcing the 2 detachable wings from the main frame body.

Next picture show the Normal spar location on the wing and the Enforcement going along the front of the wing. Last picture show my intended location or projection of where I want a prolonged wing spar to stick out from the front of the wing (in order to fasten the rotor tilt mechanism on it).

Thats the plan, but I don't know just how to drill a whole in the wing to extend the spar plus moving through the enforcement already in the front of the wing. Well I have an idea how to drill the whole but not how to treat the enforcement. If cutting it off in two pieces it will weaken their designed capability to stiffen up the wing. Maybe better bending it up or down and let the extended wing spar pass?
« Last Edit: April 26, 2017, 05:06:15 pm by karla »

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #18 on: May 01, 2017, 08:14:34 am »
Solution.

First tried to cut out the wing enforcement to move it up or down to let my extended wing spar pass though it. But it was glued tight all over and can't be moved. So I took my lovely Dremel out and just cut it off, feeling I will put hot glue in the cross section and make the design strong enough.



Some pictures attached.

Next challenge is the tilt rotor design, make and implementation :)
« Last Edit: May 01, 2017, 08:27:52 am by karla »

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #19 on: May 03, 2017, 09:06:46 am »
So I was looking for a good Tilt design to hold the parts at wing tip.
These are the parts: motor and prop, servo and ESC.



Maybe a design like this is good:



or like this,
I liked this design and would have been happy to copy it completely but
the design files were not made available in spite of direct inquiry.


So I had to get in to 3D design to make it myself.
Checked several CAD/CAM SW and settled for Googles Sketchup
https://www.sketchup.com not because its free but it has so many instruction videos on youtube.

So the designed 3D parts I did are 4 plus a 450 Helicopter feathering shaft with bearings.


I also had to find someone who could print these designs since I do not have a 3D printer.
This site was really helpful in finding a printer :)
https://www.3dhubs.com

And I have to recommend Mr Si at this particular Print Hub in Beijing where I live, very responsive, fast and good quality.
https://www.3dhubs.com/service/printer


Then I mounted them like this:


And with a final mount on to the extended wing spar on the Fixed Wing like this:
The whole unit is 70 grams.



Next challenge to complete the build.

Attached are the 4 items of 3D design I finally used.
« Last Edit: May 03, 2017, 10:13:48 pm by karla »

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #20 on: May 03, 2017, 05:36:05 pm »
I think it may be good to have the motors closer into the body?   At least not all the way out at the tips.  More stable, less stuntable, easier to tune.

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #21 on: May 03, 2017, 10:26:45 pm »
yes, maybe. The first try is just to place motors as close as possible to body but just so far away the props don't hit the wings. Can be adjusted later if needed by cutting out the wings a bit to give room for the props. Will see how this works first though. Anyway i am concerned with this much mass far away from COG, 70 gram on each wing. Its interesting to see what will happen

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #22 on: May 07, 2017, 11:15:42 am »
Hi all,
I am running in to a wall here.
The right hand motor starts hesitantly but do start but the left hand motor sort of coughing and don't start.


However, when I put both motors on a short wire from ESC to the FC like 15 cm then they both behave fine.
Problem is i need them to be out on the wings like 50 cm away (too much to ask?).
Why is this and How to get around it?
Thanks anyone :)
K
btw I have checked with my voltmeter the continuity of all cables, they are fine.
Another thing to mention is that its seem its only the signal wires that seem to matter if they are short or long, not the voltage cables to the ESC and motors ...
« Last Edit: May 07, 2017, 12:01:47 pm by karla »

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #23 on: May 07, 2017, 10:09:26 pm »
Thank you again.
Its powered by a 5 in one board that can take in 2-6 LiPo cell in serial and outputs 5.0 volts to the board via the BEC that say can take 3 Amp of current. Don't know if that's enough but the same board is working well for quads with gps on and 4 motors. This build has 2 motors and 4 servos.
 
It does not matter if the GPS is attached or not or the motors but if I only have 1 servo (any one) then it don't reboots but as soon as two (any 2 or more) servos connected to the FC then it starts rebooting.

What to make of that?
That could be your problem... when you go to move the board around a lot with all four servos it might overdraw the BEC and cause it to shut off temporarily, just a thought..

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #24 on: May 08, 2017, 12:09:49 am »
Yes, agree kicekilla. I think that was the problem. The solution was to to change two of the servos to simpler ones that did not consume so much power. That stopped the problem.

The challenge now is to get the ESC/Motors to start and run smoothly.
Its really puzzling.

Maybe my extended wire from the FC to the ESC has a different quality?
It seems this wire is the only thing that is changed from when its running okay...
or maybe just because its 5 times longer than normal
Any ideas?

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #25 on: May 08, 2017, 12:51:41 am »
sorry for replying to an old (solved) problem... didn't realize there was 2 pages  ::)

Interesting that it works with the short wire and not the long. Have you tried calibrating the esc's with the long wire?  maybe try switching esc refresh rates.

i have heard of problems by having too long of power/3wires going to the esc but never the signal wire...

Also, good job on the project, looks fun! Ill be following.

Yes, agree kicekilla. I think that was the problem. The solution was to to change two of the servos to simpler ones that did not consume so much power. That stopped the problem.

The challenge now is to get the ESC/Motors to start and run smoothly.
Its really puzzling.

Maybe my extended wire from the FC to the ESC has a different quality?
It seems this wire is the only thing that is changed from when its running okay...
or maybe just because its 5 times longer than normal
Any ideas?

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #26 on: May 08, 2017, 01:11:00 am »
Haha no worries!
Wow several good ideas!
Have not tried any of that - will get to it!
Thanks

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #27 on: May 08, 2017, 04:28:09 am »
your video looks like a motor timing issue to me, just confusing that it works normally when the signal wires are short. Let us know how it goes.

karla

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Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #28 on: May 08, 2017, 04:45:42 am »
you think the signal wires may have a short circuit?

Re: My LibrePilot VTOL TiltRotor FixedWing
« Reply #29 on: May 08, 2017, 05:12:42 am »
no I don't think you have a short or it wouldn't work at all probably. I would just try the re-calibration with long wires as well as trying different refresh rates.