HK Super Mini Quadcopter_ Build Log

glydr

How many letters do we ge
Hobby King HK Super Mini Quadcopter _ Build Log

I was at my usual post office sending some packages yesterday when the friendly posty said that I had a package. Woohoo!

Opening the box reveals as follows;

IMG_3464.JPG

1x ply frame
4x funny motors
1x HK control board
4x HK 10a ESC (never used these before, hope they are ok)

::EDIT:: Avoid the fixed wing HK10A ESCs!! Use TGY Plush 12A (see purchase list below) ::EDIT::

2S 1000mAh lipo (nanotech)
Turnigy velcro strap of awesomeness



A closer look at the funny motor. Not 100% sure about this, though the mounting tabs are a perfect fit for the frame! Will spin one up later and check it out.

IMG_3465.JPG



First impressions, the frame is quite good with most connections fitting quite fine. May need to have a small file or sandpaper handy for some connections.

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glydr

How many letters do we ge
By the way, we are talking about the smallest and cheapest quad available from Hobby King. The $30 'Super Mini Quadcopter' (I'm thinking HKSMQ for short).

20946-5.jpg
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=20946

Possibly a method of unloading some funny motors in a hurry (?) but at $30 I'm not complaining. I've spent more than that on kits similar to the frame.

------------------

You will need...

Quad kit with motors: $28.95 / 325g
HK KK control board V2.1: $14.99 (down closer to $12 with buddy code) / 99g
AVR Programmer: $4.75 / 35g (~ 50c cheaper on the buddy code)
TGY Plush 12Amp ESC x 4: $37.88 for 4 (again save a few $$ on buddy) / 140g
TGY Nano Tech 2S 1000mAh: $5.87 / 99g
Male to Male connectors for the board to rx: $4.00 / 28g ($3.05 on buddy)
Battery strap like this: $1.59 / 9g (this one will need some serious trimming, I used a smaller one that I had in stock.
Double sided foam tape for KK board mounting: $1.29 / 27g
Prop saver rubber rings: $2.04 / 9g (the item linked is a perfect fit, some saving on buddy)
6030R (reverse) props: $2.64 / 29g (buddy active)
GWS 6030 normal props: $3.26 / 33g (buddy active)
And highly recommend lipo alarm: $1.82 / 10g

That makes $109.08 without post or receiver, however there is easily $10 of buddy savings in there. And the AVR programmer can be used for other multi rotors.

You'll also need battery connectors, heat shrink tube, solder and a soldering iron of pretty good power (e.g. 50W). No need to buy additional power wire as the ESC wires are _just_ long enough.

DO NOT buy H-King fixed wing ESCs for this bird (as pictured in the first post). They aren't fast enough.

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And to save you going to page 9/ 10, here be the vids:




To see how I got to that stage, read on!
 
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glydr

How many letters do we ge
And so to build.

Starting off with the arms glue the landing legs together.

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I'm using garden variety PVA white glue for the build. From the local hardware shop.

This landing leg is attached to the frame. Note which way is down!

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The central former is glued in place in a similar fashion as is the motor plate.

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Note that the little tab sticks out the edge. I place the frame off the edge of the bench so the assembly can sit flat on the bench.

Incidentally, note the glass sheet on my bench. You won't find a flatter surface within the modelling budget! I've been building off glass for some years now and highly recommend it. Chat to a glazier as to why you want the glass when you buy it; a thermally treated safety glass will shatter if loaded incorrectly. For not much money a friendly glazier will provide a scrap of laminated plate glass with bevelled edges.

Next step is to glue the top arm in place.

Once together I squared everything up using aluminium angle from the hardware shop attached to the assembly with these nifty spring loaded clips (also from the hardware shop, Bunnings has good stuff!).

IMG_3475.JPG

Everything is weighted onto the bench with old gell-cell batteries which are a handy size and weight for situations such as this.
 

glydr

How many letters do we ge
Let dry. And then you have one of these.

IMG_3476.JPG

Repeat three times!

I have to say I always thought they looked a bit ugly in the photos. But now that I am building one close up I think it's a neat little frame. Perhaps my love of traditional kit building is making me partial towards this quad.
 
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ananas1301

Crazy flyer/crasher :D
True! I wouldn´t complain either! That is a great combo I think, if it works okay, because that is all it need to be doing, isn´t it.
The only thing I worry about with those kind of frames is stability. It will probably fly excellent when balanced out everything and trimmed but I guess a crash will damage it pretty badly. With that price I think I couldn´t resist either, if I had the money and ability to order from HK.
 

Burg

Never catch a multirotor
Very good thread Glydr !
Nice quality photo's too.
Looking forward to read your motor test.
Mark.
 

glydr

How many letters do we ge
Next step is to attach all the arms to each other via the center parts. You may choose to not glue one of the center frames in place at this stage to make ESC installation easier.


The HK10A ESCs happily squeeze through the central hole so I glued mine together at this stage.

You will end up with a neat little frame as per the HK website:

20946-2.jpg
 
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glydr

How many letters do we ge
Cheers all. The camera is a Canon Powershot compact, the same I use for aerial photography. I'm 100% Canon these days for stills.

HKSMQ arm #3 is drying as I type. Kid #4 is on my lap making typing difficult (1 1/2 year old boy).

Plan to set up a motor test towards the end of the week. I'm lazy at getting the soldering iron out but have another soldering job with a glider I'm building for a mate which will force me to get the iron out.
 

glydr

How many letters do we ge
The build continues

Tonight we have a closer look at the funny motors. They do work, but depending on how lucky you are you might need to do some work.

Here is proof that they work:


But I had a bit of work to do to get to that stage!

It was obvious while winding the bell by hand that it was rubbing. Try it on yours, you should feel it. If you have any doubt hold the motor on the frame and spin again. The reverberation of the frame will make the rubbing amplified and very obvious.

If you have no rubbing - woohoo! All good!

If any do rub (3 of mine had this problem!) take the time to fix using a trick from my CD-ROM motor winding days....

Step 1: Remove Bell

See the circlip? That's the C shaped thingy. It has to come off and be found afterwards.

IMG_3487.JPG

I use a small screwdriver prised into the C and gently pushed off down towards a towel. The towel is useful because screws, nuts, washers and (usually) circlips generally stay where they fall on a towel. If you drop a screw onto a hard table or workbench it is guaranteed to bounce off onto the floor and behind a heavy object.

Good tip, eh? You're welcome.

Now is time to slide the bell from the stator.

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That brass washer is loose so be sure not to lose it, and note that it sits behind the circlip. A small pile of magnets seen in the background makes sure that the circlip doesn't get lost.

Step 2: Colouring in

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Take a whiteboard marker and colour the stator. In the example below the right visible half of the stator has been coloured red while the left half is yet to receive this treatment. Try and get a good even covering.

Once done, slip the bell back on and wind by hand. The rubbing will remove the texta mark (don't use permanent marker!). Give it a few good turns for good luck and slip the bell off again.

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Careful examination will show the parts that are in contact with the bell. In the background of the photo above is the small file which I used to file down the stator where the marker was removed.

Step 3: Re-assemble

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The photo shows a neat, sharp nosed pair of pliers I use for re-attaching circlips. After slipping on the brass washer align the circlip with it's notch on the shaft and apply gentle pressure with the pliers between the middle of the 'C' and the shaft. Again, do this above a towel in case the clip slips off and falls.

Problem fixed.
 

glydr

How many letters do we ge
PS - excuse the funny basket in the video! Kids toys end up on my workbench to get fixed!

Once the motor is good, slip the ESC through the hole in the top of the frame into it's location in the arm. Then solder the motor wires to the motor. Because there is not much room to move I taped the wires onto a block of wood to help keep them in place while soldering.

IMG_3495.JPG

Some spare screws that I had at hand served to attach the motor to the frame.

Once installed run the motor up with a servo tester connected to the ESC and a 2S lipo plugged into the motor wires. I found a mini JST equipped lipo happily and safely takes each individual battery wire without having to temporarily attach a plug. Ascertain motor direction with a fold of tape as per the motor test video in the last post (thanks for the 'fast tip' Chad and David!) and mark that direction with an arrow on the arm.

It doesn't matter which direction the first motor spins. The rest will!
 
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KKArioKA

Epoxi Flyer
nice log, subscribed !! i was worried about those tiny motors .. if your build come out ok im next in line :D

good luck and do it in a way i can copy later hahahhaha !!!!
 

glydr

How many letters do we ge
nice log, subscribed !! i was worried about those tiny motors .. if your build come out ok im next in line :D

good luck and do it in a way i can copy later hahahhaha !!!!

Cheers. That's the intention. There isn't a lot about these things out there yet so I thought I'd write the first build log. I'm hoping it will help some people give quad building a go, particularly because this seems to be the cheapest quad on the planet.
 

colorex

Rotor Riot!
Mentor
Very good tricks there!

I really like the marker trick, but how do you make sure the motor doesn't get unbalanced afterwards?

Very nice and clean build!

EDIT: Idiot me, the motor won't get unbalanced by scraping the coils... It's a brushless motor.
 
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glydr

How many letters do we ge
It doesn't matter which direction the first motor spins. The rest will!

Now it's time to install the rest of the motors. As with the first place the ESC in the frame and solder to the motor. Before slipping the heatshrink over the join plug in a servo tester to the ESC (set at 0) and plug a 2S battery into the motor wires of the ESC.

As mentioned before, I found the motor wires happily slid into a JST connector. Pictured also is my trusty servo tester purchased for ~$8 online.

IMG_3501.JPG

With these in place carefully run the motor up with a piece of tape on the shaft to ascertain motor direction. If the direction is correct shrink the heatshrink in place over the joints. If the direction is incorrect reverse any two motor wires to get the motor to spin in the correct direction.

Which way is the correct direction? I chose to go for a 'X' quad and so referred to David Windestal's excellent diagram from his website http://www.rcexplorer.se/Educational/kkguide/kkguide.html

motorsquadx.jpg

------------------ :: EDIT :: -------------------

The latest KK firmware (4.7 at the time of typing) uses a different motor layout.

Motor 1: front left, CW
Motor 2: back left, CCW
Motor 3: Front right, CCW
Motor 4: Back right, CW



------------------ :: EDIT :: -------------------

The default KK board program from HK is a '+' configuration. So if you have no method of flashing the board or wish to go with '+' refer to http://www.rcexplorer.se/Educational/kkguide/kkguide.html for corresponding diagram for your chosen configuration.

Working around the motors one by one draw an arrow on the arm to make it easy to check your quad against the diagram.

IMG_3500.JPG

Getting there:

IMG_3499.JPG
 
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glydr

How many letters do we ge
Here is a vid of a bad (rubbing) motor running.


Compare with the repaired motor.

 

colorex

Rotor Riot!
Mentor
Johntra:

Before slipping the heatshrink over the join plug in a servo tester to the ESC (set at 0) and plug a 2S battery into the motor wires of the ESC.
As mentioned before, I found the motor wires happily slid into a JST connector. Pictured also is my trusty servo tester purchased for ~$8 online.
 

glydr

How many letters do we ge
Hey Johntra,

Sorry to not be clear!

The servo tester (much like the link you gave) is simply used to provide a signal to the ESC. Saves having to get out a transmitter and receiver. The 'test' is simply running up the motor to check operation and direction.

In the first vid above the 'bad' motor makes a horrid sound while the second sounds better (despite having some vibes which will need to be fixed). That's the extent of the 'test'!

There is equipment out there to find out a motor's KV, internal resistance etc etc. This quad is too cheap and cheerful for such attention!

As for the build, I am waiting for package #2 to arrive (hopefully this week) which contains props and male to male leads. Before it arrives I'll be soldering up the power connection and maybe chasing vibrations in the motors.