AH-6Z Littlebird Night-Ops build project

Brucey · October 04, 2013, 09:17:37 PM

That was spooky to watch. Such natural movement

Teamftp · October 04, 2013, 10:16:35 PM

OMG!!!

There are some things that are just to freekin AWESOME and this is certainly one of them.

WELL DONE, it amazing to see this!!

chris-s · October 04, 2013, 10:31:20 PM

Friggin awesome!

Chris

wgt40w · October 05, 2013, 12:32:42 AM

No. 5 - he's alive.

I suppose if, heaven forbid, anything was to go wrong - You could blame Juan and as he is so realistic, everyone will believe you !!

Zeeflyboy · October 08, 2013, 12:35:53 AM

haha, thanks guys.

I love watching that video, it makes me think I'm that much closer to finishing this thing!

No pictures this time but I spent almost the whole day wrestling with my control systems...

Firstly I needed to get the Channel wizard talking to it's friend in the Heli... after programming it all and a few false starts I got that working by forcing a calibration signal through hyper terminal rather than the onboard button. Channel 12 is now nicely encoding the 6 position, 3 position and 2 position x 3 switches and decoding them out on the aircraft.

That small success out of the way I went on to try and set up the Naza with the new system. This is where it went wrong... Everything appeared to work fine apart from channel 4 (rudder) and channel 7 (flight mode) which were showing hard right in the Naza calibration screens. Removed the leads and connected servos to the deocder outputs and they functioned as expected... CONFUSED. I spent hours going through everything, tweaking ppm frame rates, code limits, removing the ppm decoders and connecting direct to pwm ports, swapping channels... nothing. I got frustrated and the only thing I could think of was that the rudder port on the naza was broken... so to confirm I plugged in my Jeti Rx, but that worked perfectly.

Then after some more swearing and fiddling it started working. But the settings were mostly all back at how they had been to begin with.... so I'm not sure why it started working. My working theory at the moment is that channel 7 was forcing a naza failsafe condition, but why that would only affect rudder and U I'm not so clear on. Anyway, numerous power cycles and stress tests have gone by and it seems to be behaving itself. So, I now have channels 1-7 (Ail, Ele, Thr, Rud, Gain, Pitch, Mode) functioning correctly in the Naza, channels 8 and 9 functioning with the trinity head tracking, 10 and 11 functioning for the pod pan/tilt and channel 12 encoding Lights, missiles, guns, camera switch, OSD control for a total of 16 channels. M'excellent.

Only one thing remains which is some odd throttle behaviour where after say 30 seconds it ramps down, spools up, ramps down spools up and then holds. This could come from anywhere (ESC, Batteries, Naza, control system) but I had had enough of diagnosing errors for one day so it'll have to wait for another day. Once that bug is tracked down however it'll be time for some new test flights with the new control system, head and tail.

In other news some more paint arrived so I can get on with finishing the fuselage off too. The list is finally getting shorter!

Zeeflyboy · October 08, 2013, 06:57:23 PM

Been busy today...

First up I put the finishing touch to the hellfires - a nice golden dome ;)

I also completely repainted the front fuselage with the correct colour this time, pre-shaded, weathered etc again. Just needs a clear coat now but the colour matches which is better lol.

You may remember I said that the velcro straps at the back were tricky to undo when the mechanics are fitted in the fuselage.... time for a solution! First I printed a retaining bracket to install at the rear of the plates, then I printed a battery box. The box has a few advantages too - it keeps the wires of the battery tidy and also makes the battery mostly black rather than a shiney blue thing. Very simple, just insert battery into the box, slide into place and strap down with the forward strap.

Given the mechanics will be getting tested again I need a GPS mount too that would hold the GPS in a similar position to the final fitting. Printed this little mount up to do that.

that's all folks.

Zeeflyboy · October 10, 2013, 11:00:33 AM

Ok, I thought the big expenditures were over....

I was wrong. A spanner has been thrown in the works... It's changed everything.

Fortunately it is a rather awesome spanner.

I've just been offered a DJI Ace One at a price I can't refuse. Aside from the obvious advantages of some serious professional grade hardware and waaaay more configurability than the Naza, it also brings a really important feature - RTH. Given the expenditure already put into this, I figure this (last?!) expense might be worth it to gain the safety and comfort factor of RTH.

It also means I have the option to add semi-auto landing and take off, which would mean I can FPV from start to finish. It's another 300 quid to enable that however, so I'll see how badly I want it later.

However this is devastating news, because the Ace One has no led/USB puck like the Naza... My Naza hatch is now defunct! That was the best bit :(

The LEDs for the Ace One are built into the GPS puck. It is slightly larger, but I purposely designed my GPS holder with a little "growing" room so should be fine. I will just need to come Up with a small locking system for the upper plate so it can remain removable to view the LEDs.

Interesting times...

CurryKitten · October 10, 2013, 11:03:38 AM

Arrrgghhh, and it felt like it was so close to us seeing it flying in it's full glory. RTH seems like a very worthwhile investment though.

Zeeflyboy · October 10, 2013, 11:14:32 AM

Ah this won't delay me too much... I should have the Ace One in my hands relatively soon, installation into the mechanics shouldn't take too long.

In the mean time I still have plenty of stuff to be getting on with for the fuselage.

Speaking of which, I better get on with some of that!

FPVSteve · October 10, 2013, 11:34:26 AM

I don't think you'll ever fully finish - there'll no doubt be a rivet you've missed off the paintwork, or some more weathering to do once it's past X hours of flight, or Juan will elope with Action Man or something...

Makes for great reading though :D

Zeeflyboy · October 10, 2013, 12:00:04 PM

You are probably right Steve lol...

However once it reaches a state where it can fly and be FPV'ed, how long I keep working on the rest doesn't matter so much ;)

Zeeflyboy · October 14, 2013, 01:19:00 PM

Almost finished the dash... I have to say almost because the place I ordered my secondary screen from a month ago still hasn't shipped my order and has ignored the 2 emails I've sent to chase it up.

Anyway, wired up all the backlight leds and so on. So you have all the small screens illuminated, the main screen displaying the FLIR feed (and eventually a secondary screen displaying a nav display), you have the three mode indicator LEDS, red = manual, amber = atti, green = GPS Atti, and finally the larger led to the left of those is from the firestarter.

Zeeflyboy · October 14, 2013, 01:36:50 PM

I forgot to post this too - done some wiring for the weapons pods. I took some 12 awg and stripped the silicon sheath off, then ran two smaller wires through the silicon. I printed up some small hooks to attach the cable to the side of the arm.

This will actually all then hook up to a 6 pin connector at the end which means I can quickly add or remove the weapons arms as required. They'll just slide over the spars and then connect into place.

stevec · October 14, 2013, 03:50:17 PM

This has to be the best ever scale heli build thread, let alone one with the added fun of FPV.

I cannot even begin to explain how excited it makes me feel to see this model. unbelievable.

the attention to detail is utterly incredible. everything looks so professional.

well done is about all I can say.

I can't wait to see this take to the air.

/Steve

Zeeflyboy · October 15, 2013, 10:53:36 PM

Thanks! Definitely not one of the best scale build threads though... I'd say one of the best scale FPV builds, because I'm pretty sure there aren't any others lol.

So I've been having big problems... nothing is ever easy. Testing has shown a glitching problem with my EzUHF setup... I've spent several hours on it now.

It seems firmware related. It'll happily sit there with no glitches but when you start moving the sticks you get occasional and random but severe glitching.

I moved back to v1.43 and the initially thought the problem had gone, but very occasionally if you try really hard on the sticks/switches/pots you can force a small glitch. The frequency and severity are much reduced however which points towards the EzUHF firmware being the culprit.

Needless to say though I'm not willing to trust my AH-6 to a glitching control system so it needs to be sorted out.

Made this video:

http://www.youtube.com/watch?v=DfLm9JRjmj0

Now the good news. Anthony from ImmersionRC (the main programmer for the EzUHF) is going to drop round my appartment tomorrow and pick up my gear for testing. If anyone can get to the bottom of it, it would be him. So hopefully this will all start to come together soon. Ace One is being posted tomorrow, Anthony is planning on dropping back my kit by Friday - all being well I should have the mechanics operational again by next week in time for my days off. Fingers crossed!