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May 23, 2016, 12:35 PM
Storm Runner guy
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Discussion

Broken quad - gyro nulled - Microball !


I've seen conversions discussed of heli's to planes, most notably in the 'Cheap helis to planes' thread in the Indoor and Micro section.
But a quadcopter ?
A pico quad ?

In December of last year I ordered a Fluoreon FX-10 and it arrived with a binding motor. The first flight saw it zoom off to the right into a livingroom wall...of course the soft cushiony couch was to the left.
After attempts with graphite, thin oil and more the quad only ever gave about 2 mins of flight and likely struggled all the while with that motor. I then swapped it out with a salvaged spare and, the new motor had much more power than the others...didn't fly right at all.

What to do ?

How about converting to a diff thrust plane, steering using 2 of the motors.
I knew that the gyro would need to be defeated, yet had only ever seen heli's discussed and mostly WL Toys receiver based. Hmm. Well, it was doing nothing sat around unflyable.
A search on the chips was embarked upon, The first was found to be the radio chip, but the 2nd was indeed the gyro, an N540. However, no datasheet was found.
OK, well, it has to connect to the main processor on the other side of the board, so some circuit tracing was embarked on and 1 line did indeed go through the board to the other side. That trace was also, semi conveniently near the bottom of the board, but inconveniently right above the lipo connecting points !
Firstly, would it bind with 2 motors missing ? - yes.
Careful tape placement then saw the cutting of that trace.
The quad board then didn't bind....oops.
It dawned on me that the quad will check it's gyro positioning to know how to spin up the motors. The same way as others refuse to spin up if placed on uneven surfaces,

On trying to bridge the gap cut in the trace with the soldering iron, I witnessed a tiny 0.0001uF or similar SMD cap become stuck to the end of the iron....went to bed.
Next morning, the trace was repaired, the board did again bind, but the 2 motors reacted to the movement of the board. Hmm. So what did the capacitor do ?
It seemed to link to the bottom left pin of the chip, so I bridged from the trace to the right side of the missing capacitor spot.
Presto! it now bound fine and the gyro outputs were nulled.

15 minutes and 1 polystyrene plate later, a diddly version of a Nutball had taken shape, the Microball.
6" diameter, 7 grams AUW including the stock 80mAh lipo.

Flight time is a good 6 minutes, compared to the 2 minutes originally. There's now a spare motor and she will float around on 1/4 throttle in calm conditions. This does however also carry on a trait of Nutballs, it will happily fly in 5mph+ wind too.
All in all, a 2.4GHz backyard flyer solution.

Broken quadcopter - converted to.... (4 min 16 sec)


If anyone has a broken quad, the boards or similar otherwise junker parts, i'd love to convert different models. I can only pay postage due to finances, but would be very grateful and would certainly post a How To for others to convert theirs.
Last edited by Slider2732; May 23, 2016 at 12:41 PM.
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May 23, 2016, 01:02 PM
Waste Nothing
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Slider :

Kudos mate on this project ! You may have just provided this geezer with new inspiration as to what to do with the left-overs of my recent pico tricopter project (blog posted) . Interesting to note the explanation of 'nulling' the gyros that you mentioned . A few more detailed pix would be appreciated IF you can swing it . I gotta try this one ! No worries on doing the electronics by this electronics engineer , but am wondering of the connections of the under side of the board shown .

The 'Nutball' platform is perfect for your demonstration . A flying wing , as it were . Can the remaining motors be reconfigured to retain any of the other missing flight functions ?

Awesome mate . You definately have something cutting edge in this !
Latest blog entry: Filament Fridge ?
May 23, 2016, 10:06 PM
Storm Runner guy
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Thread OP
Thanks Rick.
Am glad if it has inspired (perhaps not DJI Inspired, but that would make one huge diff thrust plane !)

As things settle down from the joy of actually doing this, it seems to be a really good cheap idea for a 2.4GHz micro platform. I can imagine that lots of folks might want to convert theirs. Had a blast this evening, just after sunset with the blue lights on the front making it a sort of night flyer.
As to extra functionality...well in the old days of 2 channel toygrade, there were mods to convert diff thrust to motor and rudder. That's one option to try (if I had more quads lol).
The rear motor outputs would spin up for a Lancaster mind you, as is.
Tried a 130mAh lipo on it for an AUW of 11g and it struggled, which used to be the limit anyway for similar 2x4mm aircraft in the past. 1x4mm usually does 4g, if anything can be built that light.
Oh, nearly forgot, if I press the right stick in, it goes into what should be flip mode, but like this it becomes a really heavy flip bank, a sort of snap spiral. Haven't tried yet for Headless mode etc, could produce some funky stuff.

Some more pics of the mod attached.
It's just the bottom trace that's next to the lipo contacts, connecting to the right pad of the removed capacitor.
If there are several similar chipped quads out there, perhaps CX10 and the rebadges of this, then it may appeal wider as it is.
Last edited by Slider2732; May 23, 2016 at 10:22 PM.
May 24, 2016, 05:36 PM
Waste Nothing
RickC_RCAV8R's Avatar
Slider :

Thanx so much for these detailed pix . I think that I have enough to be able to proceed with my little project . I have an extremely light foam wing core of some warbird model that a friend gave me to use as the base . I was thinking of a twin KAOS but will try a flying wing nutball first to verify your idea . I found thru experimentation with the micro tricopter project that the larger motors used on most axial helis will easily work with the CX10 board as their output transistors will handle the current . Thanx again .
Latest blog entry: Filament Fridge ?
May 24, 2016, 06:12 PM
Storm Runner guy
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Thread OP
Was a bit worried about the close ups, but they seemed to work out ok. I used a 35mm cameras lens in front of the regular camera.

Am looking forward to updates about your conversion !
(will check your Blog every day LOL)

Great to know that 8mm will work with a CX-10 board.
Main thing being though, that if even teeny quads like the CX10 can handle larger motors, it opens up so many more ideas. At that point and with a likely faster plane, the range would begin to factor...fun stuff.
Jun 15, 2016, 09:56 AM
Registered User
This is EXACTLY what I want to do with my micro quad. It's the reason I bought it in the first place but the gyro thwarted my plans. My quad is a generic no name -pic attached. I can't quite see where that red wire is going from your pics. Can I trouble you for some more detailed info? I don't know much about those circuitry bits but I've got good eyes, a steady left hand, and pretty good soldering skills. I'm going to PM you this exact same message just to stress how much I need your help.
Cheers
Last edited by Standard issue; Jun 15, 2016 at 10:16 AM.
Jun 15, 2016, 05:38 PM
Storm Runner guy
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Thread OP
Summary - I wish I had a Cheerson CX-10 !
if it wasn't for finances i'd have tackled this one.

Unfortunately, I don't have the chip numbers for it, but could find out from the main thread in the main postings.
As an educated guess....referring to the (upside down) pic above. All chips are on 1 side. The smallest should be the gyro and it connects at various traces to the main largest chip.
1 of those wires will disable gyro updates, such that the main processor thinks the quad is always on level ground. That's what i did with the FX-10 to defeat it.

Because of the clean tracks and large amount of room on the board, the process would be to individually cut and resolder the traces that go from the gyro to the main processor.
If it doesn't work, resolder, if it does work, it's done.
Feb 02, 2017, 07:05 AM
Registered User
just destroy the gyro.
there is a microscopic ball with contact from case to some traces below .


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