This is my chronicle of my build of the M250 mini quad from Fatsharkstore: http://fatsharkstore.co.uk/m250-mini-quad-carbon-fibre

By now, the format will be familiar to a lot of people. The mini 250 sized quads are becoming quite popular among builders. Representing great value for money and with the newer generation of 32bit flight controllers the result is a very agile and performant aircraft.   Used for everything from 3D to FPV flight, these are also very versatile aircraft.

Visually, the M250 came out of the box looking very good indeed. The machining quality was perfect, there were no blemishes to the surface and all of the parts were inside the box, packed economically but sufficiently well so as not to sustain damage in shipping. What arrives in the box are 3mm rotor arms and 2mm plates, three for the core of the quad and a smaller plate for the recording camera.  There is another vertical plate supplied upon which to mount the FPV camera itself, suitable for one of the many board cameras that are available.

Flight Controller
For this build I have decided to take a different approach and have picked up a CC3D from Phil at makeitbuildit.co.uk.  I elected for the £3 soldering service and Phil phoned me to discuss how I wanted the pins mounted. I took up his suggestion of mounting them on the underside of the FC and angled inwards. This serves to keep the dimensions very compact and fit the M250 perfectly, with an aperture in the middle plate to which the ESC outputs align perfectly.

Topside:


Underside:


I have never used a CC3D FC, so this will be a bit of an adventure.  A few on here have, so I';ll no doubt be knocking on your door for advice and assistance ::)

Edit: See post number 7 below - The Receiver port layout is as this picture. Be very careful to connect correctly to your Receiver or you will burn the RX out. Ask me how I know ::)




The build so far

RCX 1804-2400KV motors have been chosen for this build.  I have used these before and they produce good power from a 3S LiPo and return good flight times out of 1500mAh and 1800mAh.


I bought the optional 15mm anodised stand off posts from Fatsharkstore. These make a good gap between the plates within which to mount the ESCs (SimonK 12A branded by Fatsharkstore)


The motors are mounted to the rotor arms using M2 5mm hex bolts. I have not yet used Loctite to hold them in. Be careful not to over-tighten, the RCX motors are made of aluminium and can strip their threads easily. Ask me how I know this 

Also, the motor mount holes in the rotor arms do not fit these motors and had to be elongated towards the centre hub. This was easily done with a flat diamond file. If you haven';t got one of those then working gently with a 2mm metal drill bit will also do.


Looking down from the top, the entire air frame is temporarily assembled


And how it looks from the underside


15mm nylon posts are installed, nylon screws holding them in place, and the CC3D is temporarily mounted to the posts.  This is how I expect the mounting to remain. I have not found it necessary to use anti-vibration mounts for the FCs in these 250 sized quads, so far.


From the right hand side, the output pins angle inwards, keeping that side of the quad clean and tidy


And from beneath the CC3D the output pins line up very favourably with a hole in the middle plate


Another [zoomed out] view from the underside, now with the FC installed


The build so far ... and breathe 



Next steps
The next task is to mount the ESC on the bottom plate, along with the PDB (an Afro board from makeitbuildit.co.uk).

With that done it will be time to power up the aircraft and start configuring the CC3D using the Windows GUI app for the purpose.

More as it happens ...

nice build, is it to tight to fit the ESC';s in there without the added 15mm stand offs?

Quote from: nub on Sunday,August 24, 2014, 22:41:00
nice build, is it to tight to fit the ESC';s in there without the added 15mm stand offs?

Yeah, without the stand offs the ESC would probably need to go on the rotor arms. The gap without is only the 4mm of the rotor arms.

Subscribed 

Follow this with interest as I want to build one up as a winter build. Will like to see how you get on with the cc3d . Good bit of advice on the pins 

Today I';m looking to mount the electronics and power.

Nylon bolts and nuts to hold the PDB in place





As always, the ESC are a bit of a challenge in these small air frames. I';m going to have to juggle a few bits around. Essential to avoid creating any physical stress that could cause an ESC failure in the future. So no pressure points or abrading hot spots



This bit, for me, always takes the longest time.


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In the words of probably many a famous person ... "Oh rowlocks!. 

Today I experienced my first ever Magic Smoke moment in the hobby. Hooking up the CC3D to the brand new FrSky Delta 8 receiver I got the wiring wrong ... and the rest was a funny smell in the room.

If I';ve one criticism of the CC3D wiki and other documentation it is that it is not friendly to clone boards when it comes to the connector pin-outs.  And with clone parts you cannot absolutely rely on colour codes or pinouts.  And so I confused myself, hooked up the ground and 5v wrong    Pants!

I now know what I did wrong ... so have ordered a replacement Delta 8 and the build is now on pause.   I did have a couple of Orange R610 RXs here, but they';ve gone into hiding ::)  Mind you, the weather is dreadful so I';m in no rush for now.

Not a nice experience, but you ain';t seen magic smoke until you';ve had an esc go phut - her indoors though I';d been messing with TCP, she does have a strange sense of smell ::)

So to today';s ventures ...

A fair bit of building done and an end of day mishap (see above).

These are the SimonK 12A ESCs from Fatsharkstore.


Nylon bolts fitted to the bottom plate, the nylon nuts are used as spacers to separate the PDB from the CF sheet.


Now the PDB is mounted and ready for the soldering to commence.


Loose laying the ESCs to see how they will fit on the plate. These will sit on top of the PDB.


Now the ESC are soldered to the PDB, also a small power feed for the VTX and other electronics.


I removed the power wire from all but one of the ESCs having read somewhere that for CC3D you really should do this. Usually I don';t bother with doing this but with a new FC that I am unfamiliar with I don';t want to take any chances.


Checking for the fit - it all looks okay to me.


And here, feeding the servo wires up into the CC3D FC through the convenient hole.


Using a Servo Tester I wired each motor to its ESC, ensuring correct rotation.


Time to wire in the RX, a nice shiny new FrSky Delta 8.  Unfortunately I got it horribly wrong and put the 5v power into the wrong pin of the RX which then immediately died in a puff of strange-smelling smoke.  Game over, for now.


So here';s the problem. The cable that comes with the CC3D does not conform to the original model. Each wire is individually socketed. So the builder has to work out which individual wires are Ground, 5V and the various signal wires.  The official CC3D cable is wired to triple-plugs so there is no mistaking.  In my case, I boobed. 

The pinout of the plug on the CC3D is, from left to right, Ground, 5V, Ch1, Ch2, Ch3, Ch4, Ch5 and Ch6 PWM.  Ignore completely the colours of the wires.





And to save the same problem happening again in the future, I have removed the pins from the single plugs and inserted them into a triple plug that I had spare. Here Red is Ground (!), Black is 5V, Blue is Ch1 PWM.  Even knowing that it still creeps me out looking at those colours, where Red absolutely screams 5V.  Trust me, it isn';t!


So there you have it.  I';m hoping that the input port of the CC3D is not damaged, but I won';t know that until I can plug another RX into it and continue with the set up.

Danny that';s a real bummer!  REally odd, my two clones from different sources both have Rx port cables with standard servo terminations, and the colours are correct, i.e BLACk/red/Wh/Blu/yel/gr/orange/purple, so your cable is faulty at best.  Don';t forget you only need to connect 3 wires from one esc, the rest just require signal wire.








P.s, i';m sure i hava spare if you need it.

Thanks Andy, I got it sussed now - too late for the Delta 8 RX though.   I took the first three wires and fed them into a triple servo plug so am ready for the next go when the replacement RX turns up.  The cable that came with this one just hasn';t been made with the correct colours in mind.   

One of the downsides of using clones. But I wouldn';t pay the best part of £75 for one of these FCs. And my own fault for not checking more carefully before applying power.  I wasn';t that happy doing so!  Should have listened to the force ::)

just done the same with mini-apm and orange rx!!!

Quote from: malc on Monday,August 25, 2014, 21:52:28
just done the same with mini-apm and orange rx!!!

Gah! Bad luck fella. I fell yer pain 

gah bummer for the pair of ya';s

fingers crossed the CC3D is okies.

Thanks for the heads up, I';ll correct them as i find them, warning put on website to stop others having same issue

Cheers
Phil

Damn OCD, I';d have not slept tonight. ::)  Just reversed Red and Black to their conventional positions.

It';s like I can breathe again



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Lol!  That is a crazy cable tho, I know it is marked with the ports on the plug, but the colour scheme is loopy!  Two yellows, two blues, it';s like they ran out of coloured wire!
Still, as long as you know what goes where?
TBH, when I ordered both my boards I ordered the Rx cable as well, as I wasn';t sure if they came withthem, which they do appear to, but like I say I do have a spare if anybody is desperate! 

Yup, big confusio ...  The thing is, I now know which wire is what, but that level of detail was very obscure on the official wiki. I found it on another site after a lot of Google';ing.

I know that the official boards come with the official cables etc.  But, being a tad pedantic if I may, if this is supposed to be Open Source (which it is) then the documentation needs to be quite specific with this level of detail.  Which is a pity really, as the rest of the documentation is good, and the GUI is really quite splendid. Even pushing 3DR';s Mission Planner (Windows) utility to 2nd place in my opinion.   That said, I';d also be bold enough to say that no one else is even close!

::)

Well, yes, it would be confusing, as the instructions reference colours!  http://www.openpilot.org/product/openpilot-coptercontrol-rc-cable/ .  I suppose being open source maybe we need to double check these things first?  I';m sure I would have done exactly as you did, whether I would have spotted the mistake is anybody';s guess, but I';ll make damn sure I check with my Naze32!  Damn worrying tho. 

I think that with the Naze32 you';re in a better place because it comes without cables, you essentially make up your own.  Or, those that you buy from Phil are bleedin obvious what goes where

I';d have been happier if all the individual wires were the same colour as that would have prompted a more careful inspection and investigation before powering up.  As it is, seeing Red and Black threw me, and as they were reversed I made the fatal mistake of applying power reversed to the RX. The rest is smoky history

A bit of a pause in the build now until I get a new FC in my hands. 

has your FC gone pop too then ?

if so let me know and will sort you out best i can mate

Cheers
Phil

Doesn';t cost an arm and a leg to provide reverse polarity protection on any low voltage electronics these days.
Purely cost cutting, that';s all it is. Same with the 5v, 12v problem, just as easy to put 15v regulators in, making everything compatible with any battery we care to use.
Sorry just sympathetically ranting on your behalf. 

Richard

Quote from: philtrum on Tuesday,August 26, 2014, 12:10:48
has your FC gone pop too then ?

if so let me know and will sort you out best i can mate

Cheers
Phil

Thanks awfully Phil, that is most kind of you.  I don';t know if it has gone pop in any way. It seems to boot, and responds to the GUI software. Gyros and Accs seem to be doing their stuff according to the real time graphs. So I suppose the only true test will be to get it airborne.  I';m going to tear my box ';o bits apart tonight to see if I can find one of the two Orange R610s that I know I';ve got somewhere in the house ::)

Then will need a bit of advice on setting up an initial config.

well, am glad you are doing my duty and blowing things up 
Feel for you, as, it';s normally me that let';s the magic smoke out!

All said and done though, think I know where I will be getting the bits from for my build..... Same place as the frame came from ....
Looks like Phil knows what customer service is all about 

Quote from: Hands0n on Tuesday,August 26, 2014, 11:33:19
I think that with the Naze32 you';re in a better place because it comes without cables, you essentially make up your own. 

Just for info, the hk naze 32 does come with cables 

Quote from: flybywire on Tuesday,August 26, 2014, 21:22:58
Just for info, the hk naze 32 does come with cables 

Ooooh! I didn';t know that.  Handy to know.  I did pick up a set of cables from Phil that are customised to the Naze32, so my next build of one of those will be a bit more straightforward.