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For various reasons I need a small quad. The required spec would be:

1. Must be small - something that you could fly indoors, but could cope outside in reasonable weather.

2. It had to be cheap - for one of the uses I have in mind I might be getting 20 or so of these - so cheap is good!

3. It had to be a REAL quad, not a toy. It must be able to do all three flight modes: GPS-Lock, ATTI-hold and manual.

4. It would be good if it was built with the standard 2" flight controller boards in mind.

And I hit on this little beastie on the HK Site...

26587(5)[1].jpg

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Now one thing I like about this is it goes together just like a "real big drone" - compare it with the photo below which shows the Vulcan Black Widow I built about 6 months ago...

bw airframe.jpg

Same "platform" architecture. The Black Widow is a 7Kg+ octocopter with a lift capacity of another 7Kg, but basically you build it exactly the same as this little fella.

So, I thought I'd share a few details of the build with you. I reckon there are at least a few plane flyers out there that might fancy a go at a quad if they could get one which wasn't just a toy that presented no challenge, at a reasonable price and there was a bit of guidance about how to put it together.

So here we are. With the right flight controller the little X230, as its known will give you a fairly high spec quad at a bargain basement price - provided you build it and set it up yourself! And that's what I'[m hoping to show here - so off we go...l

BEB

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The X230 costs £62 from HobbyKing - and you get a lot in the box for that. Basically all the parts to build the frame, 4 ESCs, 4 motors and 4 props. Just add a flight controller and a Rx of your choice and your away. You will find the item in question here.

So, into the build...

Wires are the bane of any quad - there are loads of them. So any decent quad must have a power distribution board - basically its a PCB for connecting all the ESCs together!

Here is the power distribution board for the X230..

1-power dist board.jpg

(Sorry - I'm no photographer! Not all the photos are out of focus! Honest embarrassed)

Basically the outer ring will be one polarity, say -ve, and the inner ring the other. We start by giving the board a wipe with some acetone to make sure its really clean and grease free, Then we put a nice "blob" of solder on each of the pads. This is quite a small board - max capacity about 50A - so you can do this with small iron. I used a 50W temperature controlled Antex.

Here are the ESC's...

2-escs.jpg

They have connectors fitted. But frankly the connectors at the "battery end" are a bit of a pain. In my view its far better to cut these off and then solder the positive and negative wires directly to the power board. OK, its a bit less flexible in terms of taking things apart, but I find its neater and I've never had a joint like this fail - whereas I have had a connector fail! Losing one motor on a hexacopter isn't a big problem - losing one on a quad is a disaster! So, I'll solder them on.

First, we'll need to cut the wires slightly different lengths to meet the inner and outer circles of pads on the power board - like this,...

3-esc odd lead.jpg

Bit blurred again - but you can see what I mean. Then we solder these to the power board, arranging them around the board,...

4-esc soldered.jpg

Now we need to get the power to the board, so we make up a short flying lead with an XT60 on it and solder in place,...

5-esc with power.jpg

Remember, you will need heavier cable for this lead. The individual ESCs are 12A units, but this power lead will have to supply 4 times that, so it needs to be beefier.

Now for the slightly contentious bit! Some folks just leave the board like that. But I belong to the "worrier camp"! The potential problem here is that if anything shorts across these joints (remember they will be in the open) it will effective short the battery!! So, to protect against this I put a blob of epoxy on each joint as insulation. This does make it difficult if you need to rework these joints - but I think the peace of mind is worth it. But to make sure you don't have to rework them don't forget to "ring out" these connections with a meter and be sure that every joint is solid before you put the epoxy on!

OK, that's all the soldering done. Next up we begin to build the frame.

BEB

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We start at the bottom and work up. So first the bottom plate,...

6-battery plate.jpg

This will be battery plate. Generally speaking it good to have the heavy bits low down on the quad - it tends to help the roll and pitch stability that way. While we are talking about that, remember that a quad has to have its CoG in the centre - so try not to build it "one side heavy". If it is like that then it will waste a lot power just trying to stay level!

Next we add the power board,...

7-power board in place.jpg

And then the lower plate and the lower arms,...

8-lower arms.jpg

What you position on which level is to some degree up to you. As we've said the battery at the bottom is generally a good idea, and I have chosen to put my Rx on this platform - simply because it fits (height-wise) almost perfectly and it leaves the upper plate free for the flight controller which we might want easy access to. The Rx is fixed down with just some double sided tape.

Now we can add the upper arms,..

9-upper arms.jpg

Hey, it's starting to look a bit like a quad! Next the upper plate and the motors.

BEB

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Here is the upper plate in place with the motors fitted,...

10-motors & plate.jpg

The ESCs have been clamped up to the lower arms using some cable ties and the ESC servo leads have been feed through the tiny gap between the top of the Rx and the upper plate. The more you can route the wiring through the middle of the quad the neater things will be.

Next up we need to add the flight controller which of course is the 'brains' of the setup,...

11-fc.jpg

Now, there has emerged in recent years a standard in flight controllers that are all the same size - nominally 2" square. This quad has been designed to take any of them. So you can take your pick. The KK2.1.5 is a very popular basic controller and you can pick one up at HK for just £13! amazing.

If you want something with more facilities then you could go for the APM or the Micro-Wii. I have chosen the later for this quad, a Micro-Wii 328P.

The Micro-Wii is a very powerful controller. Its name comes from the fact that the early ones were Arduino boards fitted with the accelerometers etc. pirated out of an old Wii controller. Today its sold as a product and you don't need to search ebay for an old Wii unit and whip the back off! It costs £18 and you get a lot of flight controller for that; very impressive processing power (atmega328), accelerometers, gyros , a barometer and a magnetometer! It offers all the three flight modes of a much more expensive controller. What's not to like? How the hell they do that for £18 is beyond me!

OK, that's how far I got today. The Rx is bound so the next step is the programming of the flight controller - the fun bit!

BEB

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Posted by andyh on 09/05/2015 22:54:46:

what are you going to do with 20 of them?

Ah - well we've developed an MSc course in Drone Technology and Applications that we will running start running in September. As part of the course each of the students will build a DJI Flamewheel F550 as one of the modules in the first term. The aim is they will test fly it in December and then they will use it for experiments in the second term and their Master's project over the summer. All that means they have to be taught to fly before December. British weather being what it is I have to have an "indoor option" for this. This quad is a candidate.

BEB

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People are often surprised at how fast a multi-rotor can fly when it in manual - most only see them fly in GPS-Lock or ATTI-Hold when they are quite tame! The Black Widow above will easily reach 70mph in manual. And little quads are amazingly agile! This little one will doubtless do flips and piroutettes etc to your heart's content!

I forgot to mention - the Micro-Wii also has a built in pan and tilt camera control! So we can put a little Mobius on board. As I said a full spec quad for just £80 so far plus an Rx.

BEB

PS We have a couple of little tricks to make telling which way round they are easier - I'll show them later!

Edited By Biggles' Elder Brother - Moderator on 10/05/2015 00:02:16

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''I forgot to mention - the Micro-Wii also has a built in pan and tilt camera control! So we can put a little Mobius on board. As I said a full spec quad for just £80 so far plus an Rx.''

BEB

Hi all , for me a very important option because, all our RC flying activities be recorded by this small and relatively inexpensive device, which has not been the case..... so go ahead....SIR !

Jo

 

 

Edited By Josip Vrandecic -Mes on 10/05/2015 09:43:50

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Something I forgot to mention yesterday, which I'm sure will be obvious to anyone who has built a helicopter but might less obvious to plane builders. Just like helicopters MR's are basically bolted and screwed together, so if you don't want it to all spontaneously disassemble on you in-flight the don't forget - blue Loc-Tite on all the screws please!

As its another windy day here I'm off into the shed to start programming the flight controller, I'll let you know how I get on tonight!

BEB

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Posted by Biggles' Elder Brother - Moderator on 09/05/2015 21:49:02:

1-power dist board.jpg

(Sorry - I'm no photographer! Not all the photos are out of focus! Honest embarrassed)

Is somebody going to organise a whip-round to buy BEB a better camera, or an instruction manual for the one he's got? wink 2

(Still watching with interest though!thumbs up)

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Posted by Biggles' Elder Brother - Moderator on 09/05/2015 21:20:33:
I reckon there are at least a few plane flyers out there that might fancy a go at a quad if they could get one which wasn't just a toy that presented no challenge, at a reasonable price and there was a bit of guidance about how to put it together.

Count me in that category. I got the last one from the UK warehouse this morning plus a Micro Wii. 'Janet & John' style for the programming please!

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Ah, you're all far too picky about details - if they were all in focus you'd suspect it wasn't me! wink 2

Anyway to business. Its been a funny day - everyone in our family (including my son in Bangor Uni) got loads done with great success - partly at least because one-by-one they all button holed me to help with one thing or an other! The consequence being the one that didn't get much done of his own,....was me!

Never mind, here goes. Now this phase takes a lot longer to explain than it does to actually do! But I'll try to go step by step so you can see what's involved. Remember, although in places this will sound complicated - its actually quite straight forward once you get down to doing it.

Step 1. Plug the flight controller board into the computer - it has a Mini USB socket on one side. The computer should go looking for the driver (FT232R USB UART). This will probably take a while - be patient, mine took about 5mins to sort it all out. Very important at this stage is to note the COM port the set up uses. In my case it was COM9.

Step 2. We need to download the MultWii 328P GUI so we can set it up. The MicroWii is an Open Source project (like OpenTx on the Taranis) and you can find the software on Google Code. Go to **LINK** and download the latest version which is 2.4. This will give you a zip file - copy the files in there into a folder on your desktop and install, then run the file MicroWiiConf in either the 32-bit or 64-bit version as appropriate.

The programme you get should look like the image below taken from a screen shot in my computer:

gui3.jpg

BEB

Edited By Biggles' Elder Brother - Moderator on 10/05/2015 23:55:43

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Now we can test the flight controller to check it all works as it should. Basically reconnect the board via the USB, start the GUI above, set the COM port to COM9 (in my case) then press start - the board should start running as in the video below (note about the video - taken by my daughter on her iPod it was 90 degrees on it side so had to be rotated! To see it more clearly pop it out full screen).

BEB

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Step 3. Now we could fly the board at this point with its default settings - but it will be better if we make a few small changes to the software. This is basically a clone of an Arduino board with some sensors on it, so we can use the Arduino Development Environment to edit the MicroWii's software.

So, go to www.arduino.cc/en/main/software and download version 1.6.4 of the Arduino IDE. Install this taking all the default options and saying "yes" to adding on stuff like the USB driver etc.

Start up the IDE, open the MicroWii file in the folder you downloaded in the post above when we got the GUI. Lots of tabs will open - we need to edit a few of the header files so we want the "config.h" file. If you can't see it just scroll along the tabs - it is there!

Now - be very careful! You are messing about with the software that actually does the clever stuff on our drone! All we are going to do is uncomment a few lines and comment out some others. A line in the code is a comment if it begins '//' - so to uncomment just delete the two slashes. Two make a line a comment just insert two slashes at the start of the line.

Look down the config.h file find the bit labelled "Type of Multucopter" and uncomment the '#define QUADX' line.

Next find the list of "Board Types" and uncomment the line #define HK_Multiwii_328P"

Finally, we need to increase the I2C speed from 100kHz to 400kHz. To do this go back up the file a bit and comment out the line '#define I2C_SPEED 100000L' and uncomment the line '#define I2C_SPEED 400000L'

Phew! That's the edits done. Now we need to write them to the board. Select 'Tools' and set the COM port to COM9 (or whatever your port is). Then use 'Tools' again to set the board type to 'Arduino Pro or Pro Mini'. Finally writ the code back to the board by selecting 'File' and 'Upload'. There will be lots of flashing LEDs on the board, then it will settle down.

We need to retest the board - same as in the video above - to be sure we haven't messed it up!

And that's it - for stage one of the set up - we'll have some fine tuning of the gains to do later using the GUI

If you have struggled to follow some of the above (!) just bear in mind two things:

1. It really isn't as complicated as it sounds!

2. There are shed loads of videos and web pages on the internet demonstrating how to do this - so you have lots of help!

BEB

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