AH-6Z Littlebird Night-Ops build project

[wgt40w]

I take it the CNC was still under guarantee!

What caused it to blow - a major short - incorrect voltage ??

what do you think I am, A shop!  :laugh:
:) G

G - I was trying to protect your quality reputation - thought Zeeflyboy would admit to being 'under the influence' when he connected it up the wrong way round!
           ;)    ;)

[g.collins]

 :laugh:

[Zeeflyboy]

shoddy workmanship G, shoddy... lol.

Nope, all proxxon's work I'm afraid!

Anyhoo, just a quicky before I go to the car show:

Pushrod supports in place and secured with some CA glue, since the CNC machine died before I could make the part that raises it up to the servo I had to improvise with a block and some tape.




And let me ask you, how exciting is this picture? thing is freaking huge with the blades attached lol. Not much left to do - just some ESC programming, Naza Programming and a little wiring then I can go and crash it.

[Zeeflyboy]

Right, so almost done... run into a bit of a problem though.

I think it's something similar to what FPVflyer found on his Naza-H but unfortunately he never found the answer as to why it went away.

I have run through the setup and everything is fine, swash is nice and level in the trim section and so on. Switch it on in manual mode and it tilts to the right and back... weird. I know it's supposed to tilt right in atti mode (which it does) but in manual mode it should be level on the ground... or at least that's my experience with other FBL systems.

So bit of a head scratcher... I've gone through setup a few times and always the same result. I'm a bit cautious that with the swash in this position it will try to tip on the ground. Not overly bothered about in the air because I can control it then even if it's leaning, but the ground spool up is always more risky. Hmph...

This is what the swash looks like in manual mode with sticks level....




Anyway in the mean time EZUHF hooked up with temporary bunny ears, and my high tech GPS mounting system (block of foam and tape lol).






Apart from figuring out this strange swash behaviour and setting up the ESC it's now ready to rumble.

[FPVSteve]

A work of art - can't wait for the maiden vid, go steady!

[Zeeflyboy]

cheers steve - all or nothing lol.

Lol, cheers.

Well assuming it goes ahead (will see what happens with this swash problem), one of my mates is going to come along and help so I'll get him to take some video.

To make it a more meaningful test flight, I have added 2kg (4.4lbs if you work in crazy) to the front and the tail fin at the back. This should help simulate the weight of the fuselage, plus the aerodynamic effects of the tail fin and give a more meaningful idea of how it'll fly - it'll also mean the settings when it finally goes into the fuselage will be closer to the mark.

[CurryKitten]

These large heli's look terrifying - wonderful that it's got to the maiden stage.  Good luck, as we all want to see the awesomeness of this things being FPV's and with Jaun at his controls :)

[Zeeflyboy]

They can certainly be intimidating... You have to treat them with respect as they are potentially extremely dangerous if you don't of course.

Once you've flown a big heli though you get hooked. They just fly so beautifully compared to the smaller ones!

I long ago lost the "fear" of flying the big heli's, but I maintain my healthy respect lol.

[Flyn]

They can certainly be intimidating... You have to treat them with respect as they are potentially extremely dangerous if you don't of course.

Once you've flown a big heli though you get hooked. They just fly so beautifully compared to the smaller ones!

I long ago lost the "fear" of flying the big heli's, but I maintain my healthy respect lol.

+1 to that!

I know my Trex600 could pretty much take my head off if it chose to, but the key to heli's (especially big ones) as I'm sure you know is to look after them well & do your pre & post flight checks & never assume something will still be tight because it was last time - & it will look after you by not maiming or killing anyone!

I like to renew my Jesus bolts every few months, there's nothing quite like metal fatigue to ruin your day ;)

I always double check everything before flipping the idle-up switch to start the rotors & I never set the TX down inside the radius of the blades when powering up! Cos I'm sure as hell not gonna dive in there to grab it if somit goes wrong!

The build is coming along beautifully by the way!!!

[Zeeflyboy]

I still remember the first flights on the 600 something went screwy between the SK720 and the ESC damn thing wouldn't shut off.

I landed and shut her down, still kept spinning just at a low head speed. Tried trimming back on the throttle, changing endpoints, the lot - no dice. Had to crawl under the blades like something out of crystal blooming maze and disconnect the battery. I wouldn't have done it had it been spinning faster but as it was I deemed it safe enough to have a go.

Even going slowly those blades whizzing by your noggin as you try to kiss the dirt is quite something!

Anyway, ESC is now all programmed up and alive. Can't really spool it up to check for vibes because I doubt the neighbourinos would appreciate it lol.

I have however succumbed and ordered a new head. The one I have, while pretty, just has a couple too many flaws for me. First the machining variances that led to some pretty different pushrod lengths, then the fact that the swash balls aren't in line with the axis of rotation thus introducing some unwanted interaction, and finally those multi part blade grip links.

I went for this design which is simpler looking. Hopefully the quality won't disappoint... It's not quite so sexy but given it'll be in black anyway at the end I doubt it really matters much.

[Zeeflyboy]

"Tragedy.... when it all goes wrong and you can't go on it's traaagedy...."

Went all the way down to the field and set it all up...




The swash is a problem as I suspected, the heli tries to tip on the ground and requires constant forward and left inputs to stop it from doing so.... Because I'm a dick and I know FBL systems aren't happiest sitting on the ground I popped it up into the air to see if it still happened, and it did. At that point however the tail didn't hold well at all either and it started a slow nose left spin, so I was left trying to fly a helicopter that was trying to pull back and right while spinning.

I managed to pop it back on the ground from a few feet up, but due to the weight and the soft ground snagging the skid I managed to snap the front leg.

the good news - I managed to pop it down without touching a main blade or scraping the tail, so the only damage is a 2 dollar skid, but it did put me out of action unfortunately (or fortunately?)... however for a few seconds, it flew lol.






I'm now a bit lost though because I have no idea why the Naza is doing it... and I've tried every conceivable thing to fix it. I sent DJI a service request asking about it and I see they've passed me to the retailer I bought it from as I just got an email about the opening of a support thread there (not very helpful lol, my french is a little ropey for technical stuff and it's a french retailer). We'll see what happens, I'm tempted to install my spare SK720 FBL controller just to get the mechanics worked out in the mean time and make sure there's nothing there that needs attention...

[CurryKitten]

What a pain... at least the damage was minimal though.  Sadly I no nothing about the Naza-H so can't offer anything in useful advice (but hopefully someone somewhere can).  I can only say good luck getting it sorted... because me and the rest of the world really want to see this completed and involved in allsorts of exciting scale heli-missions

[dogzilla]

I can only suggested rebooting the Naza.

I have had similar behaviour with my Naza (Regular quad copter one)- started up, all seemed fine, went into a hover and then it started rotating and wouldn't bloody stop. Then i dropped to the ground and the motors wouldn't cut off until I did the corner/diagonal thing.

Then I powered off, powered back up again, and suddenly it worked fine? And I haven't seen the same issue since.

[Zeeflyboy]

Power cycled a million times, restored to factory settings twice, ran through setup countless times, re calibrated sticks even more times, nothing made e slightest bit of difference.

However FPVflyer, bless his cotton socks, has come down from the heavens riding a giant multi-rotor powered by nothing more than hopes and dreams to deliver me the answer....

And it makes no sense. Like not even a little bit. But it worked.

In case anyone runs into the same, this is the process:

A) Power up heli and transmitter
B) Get angry as swash tilts again but resist urge to throw the whole lot out window
C) Set EzUHF failsafe by pushing failsafe button for 2 seconds
D) Power cycle
E) Observe your wonderful new correctly behaving swash.
F) (Optional) get angry again because you don't understand why the hell that just worked

I also had a very slow creep of the tail servo that would result in full deflection if you left it standing for a minute or two. Also now gone.

Go figure... Now I just need a replacement skid.

[mattydred]

great stuff - looking forward to seeing it in the air