Beginners Axn Build Log

[Coyote]

Hi guys, this builds a bit different from my normal builds, the idea was to build an entry level, cheap as it gets FPV plane that performs well and is fun to fly :)

My weapon of choice was a Axn Clouds Fly



It was £30 from Hobbyking Uk. It comes with a motor ( but mine did not ) that`s junk really, no servos, no ESC no nothing..... Its a bare bones kit, but exactly what I wanted.

In the kit you get the following :



A sealed fuselarge, wings, carbon spar for wings, horizontal stab, vertical stab and a canopy. Bits and pieces consist of control horns ( junk ) push rods for ailerons, 2x prop for the motor that was not in the box :) Y splitter for ailerons and glue.

Ok, so lets begin :)

First job was to split the sealed fuse :



This is easily done with a brand new shape bladed knife, taking it slow and steady most came away fine, you have to work around the motor mount ensuring you don`t damage it in the process because I`ll use that still. 

Now I have access to all the space inside, which there is actually a fair bit if you open her up.

So whats going in the inside ?





Its going to sport a

Turnigy D2826/6 2200Kv Outrunner
Turnigy Plush 40 amp ESC
Turnigy Low RF 5amp Bec ( not pictured )
480 tvl Board camera getting replace with WDR 600tvl Board Camera
Telefly OSD
Current sensor extension board for Telefly OSD
5.8Ghz RF-Sky module
LC Filter ( Home made )
2200mah 3S lipo
Tower Pro 90Mg`s 14 gram metal geared servo
HXT 900`s or equivalent

First I did a bit of prep work on the fuse. Pictured below is the front of the nose :



I cut the marked blocks below out to house a 2200 right in the front of the nose



Now a 2200 will fit in right up front no problem :)

My Vtx will be back on the tail like a Skywalker to give me the best possible transmission and keeping vtx separated from other kit. To do this I cut a channel above the glues in spar, two cuts, one in each side of the fuse. One for signal ( video / audio ) in the right side fuse, one cut for vtx 12v power in the left side of the fuse so the power and signal wires still have separation right down the length of the plane.



I also cut the servo base deeper than stock for the rudder and elevator servos.



The reason for this is my ESC will be mounted on the top of the fuse compartment, so dropping the servos just a little gets rid of a curve from the push rods meaning free movement.

The original location :                                                 New lower location with base lowered :



The next bit of prep work was with the motor

I wanted to use the motors metal mounting still to add strength to the original plastic motor mount. So I marked up the new hole positions and re-drilled the motor mount



Apologies for the dirty nails :)

I then used the longer motor screws to screw the motor to the metal mount through the plastic mount



Much better :)

With a 7x3 prop going on I cut the fuse below to have 3 3/4" of clearance, this is because the Axn tail does flex on landings and takes a chunk out of the fuse, so instead I beat the prop to it :)



So that`s most the fuse prep work complete. I turned then to the OSD current sensor. I hate connectors, connectors can fail, they are a potential failure point being a joint and being able ( if unlikely ) to come away with vibrations. So I get rid of as many as possible that are really not needed.

I removed the current sensors heat shrink



Removed both the XT60 connectors and hard wired them in instead



Esc wires to output, XT60 connector for lipo on the input



Next I fitted the control surface horns. Another pet hate of mine is naff horns, all that time and effort building normally destroyed by a 1p pile of crap horn, no thanks........................



I replaced all mine with solid strong nut and bolt horns

The next thing was to mount the servos, to do this you really save a lot of time and hassle buying one of these :



A servo tester

I could mount the servos in the fuse knowing without anything else connected the servos were centered perfectly





Use the deeper channel to run the servo wire and glue the spar cover in place



Ok so now a big leap forward :)

No need to go into detail much but below is the left side of the fuse, my power side.



Here you can see :

XT60 going to Telefly current sensor input
Current sensor output going to ESC ( mounted ) input
Esc output going to motor ( Check direction before sealing the fuse )
Turnigy Bec on the current sensors output
LC Filter on the current sensors output for camera and vtx power.

So that is the power side done. Everything is glued in place, with a nice gap from the fuse edge so you know that there is plenty of separation between that and any FPV equipment.

I snipped the red and black wires from the Esc to isolate the Esc`s Bec from the Turnigy stand alone Bec.

You can see I ran the motor cable into a void below the motor, this was to get rid of access cable without having it in the compartment that the Fpv wires were in. You can also see the main power wires come from the XT60 connector ( on the far left ) through to the current sensor, out to the Esc while being at the far side of the fuse. This is as far away from the Fpv wires as possible which is good practice. The more isolation ( which air is ) between the power and video the less the chance of any interference. 

I also fitted the Uhf Rx ( you could use any though ) in position. The Rx can be on the FPV side as it runs on 5-6v max so does not interfere at all with video / audio



So FPV part now :)

First I cut the slot for the board camera positioning



This will give it a little less drag as it basically has the aerodynamics of a brick :)

I cut a channel show in red below for the camera wire



FPV camera then mounted, again, no connector used, cables were soldered stright to the cameras pins and glued for reliability.



I then installed the Telefly OSD, but the pictures are missing  :o

Basically, my video and audio cables were RCA leads ( shielded cable ) from the OSD output, ran down the channels cut previously to the tail. Then all other wires soldered and heat shrink`d to the OSD pins. You could use the plug for the OSD provided but you end up with a mass of wires which is exactly what you don`t want for FPV.

I plugged in the current sensor and GPS, mounted the GPS and connected up the rx servos.

Job done ! Build time was 4 hours in total from opening the box to complete, but a fair chucnk of the time was removing connectors to hard wire parts in so you could knock an hour off that.

Now to glue the fuse together



Finished product :)

[Coyote]

So how did it go ?

Well I had a faulty GPS sensor but thats replaced now.
The camera struggled - But I was going for as cheap as possible, but I will replace with the slightly more expensive WDR650 board camera and get 650 tvl and miles better light reaction.
The prop was under sized, I used a 6x5 that I nicked off PK and was unbalanced which is evident in the video.

Apart from that which is all easily solved I was very happy with the results.

No interference - This shows that with the proper running of cables, even in such a small airframe you should get absolutely no interference from your motors current.

Perfectly flyable - Even with the cheap as chips 480tvl board camera you can see enough to fly fast and as hard as you want.

Very light and agile - Even with the Fpv camera, OSD, Current sensor, Extra Bec, LC Filter and larger lipo it handles fantastic ( although wind and unbalanced prop didn`t really show how well it was )

Maiden was as you see it, no LOS flight first, just turn it on and chuck it in the air :) Confidence or stupidity ------ You decide :)

Axn Maiden

[FPVSteve]

Impressed mate, I have a lot to learn. I'm tempted to completely restart my EZ* and build it like this (luckily, I didn't glue my fuselage :) )

[electrotor]

Very interesting and well explained build thread Coyote.  :)

I eventually decided not to use my AXN for FPV but still had the problem of feeding wires to the tail for night flying, so I was keen to see the fuselage split open. I managed to feed the wires through the tailboom by careful (and lucky) use of a piece of carbon rod to drill through the foam without splitting the fuselage.
I kind of agree with your comments on connector failure but normally fit them anyway because changing or replacing parts is so much easier. I had to swap out escs on a foam twin a while back and had precious little room between the soldered joints and eager to melt foam parts.

[Coyote]

Impressed mate, I have a lot to learn. I'm tempted to completely restart my EZ* and build it like this (luckily, I didn't glue my fuselage :) )

Go far it Steve, copy it as best you can mate and you should get the same but probably better results ( my camera was limiting factor )

[hase2]

Nice and comprehensive guide, Ian.

[FPVSteve]

My camera cost $16.99 :D

I need an LC Filter that's all, 12V is too noisy, 8.4v is better but means carrying an extra battery (my leccy knowledge is crap)

[Coyote]

Hopefully this build thread should have shown you 12v gear can work fine, even installed in a small plane with nothing more fancy than an Lc filter and carefully wiring.

Now get your EZ* rebuilt using the same techniques and have it done for Bardney ;)

[FPVSteve]

I'm going to have a bash at it tonight - working at the minute.

[dirtyharry]

handy guide , especially as I bought one of these just before i went offshore ,( 7 friggin weeks ago)

will get buildin this week.

[g.collins]

Nice guide Ian.
:thumbsup: G

[FPVSteve]

I also have an AXN put away for Christmas thanks to the wife, so this build will be my inspiration for mine too :D

[mr_s81]

Thanks for the very detailed and comprehensive write up!

I'm in the process of doing the same thing with my BMI arrow. What did you use to glue the fuselage halves together again?

Thanks

[Coyote]

Thanks guys, yes mr_s81, Uhu Por was used to glue the fuse back afterwards

[KevChallis]

So how much did this cost you in total?