Bone5 - Digital UltraStretch X

By Jayembee67 on Nov 06, 2021

27  916  15

Because I am a sucker for the more outré flying machines, these new nearly-a-straight-line 'bone' frames inevitably caught my attention. It seems unlikely that something like this would really be flyable, but I've watched the videos, and apparently they are. So I had to give it a go myself.

I went for a nominally 5" frame, but the FC spacing is only 20x20mm, and the motor spacing is M2 12x12mm, so I've ended up with what I suppose could be considered a Toothpick-y type setup - AIO FC, 1804 motors and low pitch 4.5" props. The AIO Flywoo FC is compact but with decently accessible pads, has a DJI plug, and, crazily, sports 40A ESCs - but they are only BLHeli-S, so unfortunately no dynamic filtering on this strange beast. Still, as this is mostly a novelty build, I'll make do.

And of course, I just can't do the analogue thing any more, so I wanted to squeeze a DJI Vista into the stack. This did mean that the TPU canopy that came with the frame turned out to be useless - it was only built for Micro cameras, so the 19mm Polar Vista camera would not fit. As such I needed a different solution and so set to with TinkerCAD, and spent a week on and off working on a replacement canopy - each test print took around 5 hours, which was all very tedious. Still, I got there in the end, it's a bit of a ragged print but it will do.

The build itself was really quite simple, these AIO boards keep things clean, and everything worked first time - always a bonus. In my back yard hover tests it does indeed fly, and in fact hops into the air with alacrity. It's very light of course as there is very little carbon here, just 188g without battery, but I do worry that it will guzzle through a 850mAh in seconds with those big props. And then there will be the strange handling - even during the hover tests, I could feel that the yaw response was odd, muted.

Still, it flies, it sends video, and it looks completely crazy. I'll take it. Flight tests to come...

UPDATE: 2021-11-07
I put a couple of packs through this machine a few days ago, and that was a very bouncy and rattly experience. Since then I have applied a basic Toothpick tune, and so took it back out today - and now I have a decently flying machine. It is a bit unstable feeling compared to a standard X quad, and it has done something strange a couple of times, briefly losing authority at high throttle, which is worrying. But even still, this is flying way better than something that looks like this should.



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SPeCTRuM_TMD   Feb 04, 2024  

Impressive ! really nice build. Is it steady , or does it really flies as it looks ?

Jayembee67   Feb 05, 2024 

So, in truth is flies way better than it has any right too, and it looks amazing in the air - because it looks like it should not be in the air. But if we are going to be honest, its big trick is that it flies at all, not that it flies in any fancy or special way. It's a bit unstable, it's a bit rattly... but it flies and that is kind of amazing.

SPeCTRuM_TMD   Feb 05, 2024 

I would really like to see it someday.. Maybe a future build.. Hmm...

Tsarge   Dec 11, 2021  

Awesome man! Are you running dji over soft serial with that AIO? I have had some strange happenings with soft serial on the goku f411 in the .

Jayembee67   Dec 11, 2021 

Thank you! And yes, funny you should say that... After running with the DJI on the Soft Serial for about a week, I had had enough and gave up on that - far too many strange OSD glitches in the goggles. It actually felt kind of dangerous in truth as my battery details would come and go randomly, and weird junk would clutter the display.

I was going to move the DJI connections over to UART2, which seems to be there for the analog VTX, but in the end decided to upgrade the FC entirely. I went with the GOKU HD 745, the F7 version of this AIO board. This gave me two things, obviously more UARTs so no Soft Serial for the DJI OSD, and no more glitches, but also BLHeli_32 and RPM filtering, which did make a noticeable difference. It has ended up being a worthwhile upgrade - I have managed to get this machine flying surprisingly well now, and it's different and fun. Fast, too! :-)

jdmkramer   Nov 18, 2021  

Well done! I love the style you put into this build. The photos are great too!

Jayembee67   Nov 18, 2021 

Thank you. Yes, for something that is basically a single stick of carbon, it has rather unexpectedly ended up being an appealing build. I am still tuning it, but it's getting better all the time. It's never going to fly as well as a 'normal' quad, I don't think, but it now flies way better than I had hoped it would.

jdmkramer   Nov 18, 2021 

Your maiden flight video was my first time seeing one of these things fly. I guess I shouldn't be surprised with all the power these quads have, but I was! I wonder what the cruising efficiency is like compared to the same guts on a traditional frame.

Jayembee67   Nov 19, 2021 

Well, to be honest, I had the same reaction, and I built the thing ;-) I was fully expecting it to get into the air, but then be kind of terrible once it got there. But it has been a much more interesting and capable flying machine than I could have imagined. As such, I have bee putting in the effort to get it properly tuned.

And that's an interesting question, I actually haven't tried that - just rolling it gently around the field to see how long it can do that. I mean, it's a light build, almost no carbon, but I will try that over the weekend, see what flight time I can get.

Jerky_FPV   Nov 19, 2021  

Very interesting!
COuld I have the stl or link for the 3D printed part of the frame? I really like that and am looking for something to replace my BabyHawk-R canopy with.
Thank you and nice build!

Jayembee67   Nov 19, 2021 

Thank you, and yes, it really is weird but kind of wonderful! And absolutely, here you go:

Jodie Froster   Nov 07, 2021  

Great build

Jayembee67   Nov 08, 2021 

Thank you! I can't deny, it's pretty unique looking, if nothing else. And I have now managed to put a couple of test packs through it - it's a rattle monster at the moment, but hopefully a bit of tuning will help with that. Still, it does fly and is way more powerful and fun than I had expected it to be!

OptimaZe   Nov 06, 2021  

Really cool build! This style has had my interest for a bit now, but I have yet to pull the trigger on a frame order.

Jayembee67   Nov 08, 2021 

Well, I can report that it flies, but it needs work. There was a good deal of rattle and shake in the air, so tuning is definitely required. And the handling is a bit strange - I did nearly park it in the top of a tree on the second pack when it got away from me for a moment. But it does fly, and it flies surprisingly well. It's fast, quick, and agile, and so unusual all round that it's definitely worth putting in the effort to get this thing flying better.

I say go for it, this form factor has more going for it that I had expected.

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