AH-6Z Littlebird Night-Ops build project

[Zeeflyboy]

Little job for this evening

My YGE ESC has a built in phase sensor which allows it to be used with external governors, but more importantly here it allows me to feed RPM data to the eLogger... the eLogger can then use the number of motor poles and the gear ratio to record the head speed, and it also allows the headspeed to be displayed in the OSD in real time during flight too of course.

So, to make it work you just need to make an adaptor - since I needed to extend the wire anyway I just turned the extension into the adaptor. I used some 3 core shielded wire and here's the change you need to make... take the "signal" and splice into ground, then take the "positive" and move up to the signal slot on the other end with the middle slot left empty. Plug that into the eLogger RPM port et voila - shimples.... here it is before heatshrinking the end.




I'm using some great little self adhesive clips from hobbyking for wire management, you can see how the cable is routed to the eLogger... this cable will later be joined by the eLogger GPS module cable too (again replaced with shielded wire however).




Just spooled her up and it all works... after setting gov store on the ESC I'm reading 1200 rpm at 75%, 1300rpm at 80% and 1450rpm at 90% which is all fairly believable - I'll cross check figures with the tach app on my iPhone when I get the chance.

[Zeeflyboy]

Just went to pick up my new head...

First things first, I noticed it felt much lighter than the other one, and that is certainly the case. Popped them on the scales and the new one is a good 154g lighter than the original - quite a significant difference.

original




new




So, initial impression:

- The new head feels very nicely made, the links are more solid with less play and the link design is a huge improvement overall.

- Swash design is traditional with the balls in line with the axis of rotation, you can see there is less interaction and unwanted movement when the swash moves.

- Lighter but still feels very well made and strong

- It doesn't quite have the same bling bling appeal but is actually probably more scale like... it needs a much bigger head button but that is easy enough to make, I'll probably 3D print or CNC a more scale like one if I can't find anything suitable - I think with the larger head button it'll look quite good.

- slightly irritating design allows you to use 700 size blades but means spacers are required for 600 size - considering the blades need to be removed for transport and storage that's a pain in the butt. I think however if I just glue the spacers to the grips then it'll be problem solved.


here's the real deal for reference





It also has a neat little shaft mounting system - you have the jesus bolt as usual, but then you also have a small separate screw that tightens the collar down... quite a nice design as it means you aren't loading the jesus screw with the extra load of having to clamp down the head. Seems to work well, the head is very secure with no play.




EDIT - after fitting and tracking the head I really think this is a superior bit of kit... the precision is much higher and there is no play or looseness anywhere. The other one actually flew pretty well but it'll be interesting to see how this one does!

[Zeeflyboy]

Flew the new head, again it's windy today but even so the heli is certainly getting more dialled in...

For the first time I ran the ESC's internal governor and its definitely the way forward. With 80% governed it is running a headspeed of 1,300 rpm and seems to be burning around 18 amps in the hover, but still felt like it had a lot of power. It works much better in combination with the Naza Atti modes... Since the Naza locks throttle when you initiated the Atti modes when you ask for a powerful climb the ESC is still only being given 80% to work with so you could hear it bog down as it loaded up... With the governor mode obviously the ESC retains control so it can add power as required to maintain the head speed.

I am tempted to try lower still, but I'm hitting a wall as regards tail authority below about 1250 rpm. I won't test lower until the spin semi symmetrical tails arrive to address that issue...

I've upped the agility to 150% and removed all expo from the transmitter when I switch into GPS Atti/Atti modes, plus dialled in more expo for manual mode... I'm trying to smooth the transition between the automatic and manual modes and its already a much better feel.

The new head is great, very smooth and tracking was spot on again using my tried and trusted screw driver method lol... I think it's a keeper for sure.

Suppose I better get back to work on the fuselage!

[Zeeflyboy]

So tools down for a few days - it's 4 years that the GF has been putting up with me so we're off to London for a few days to celebrate.

Here's a parting gift however, a quick rubbish snap of how the cockpit is coming along. I've just painted the centre console (still needs some details and a coat of matt varnish)...




and a quick snap of how the head looks... I've already designed a larger head button for it too.




And spot lights are in place... still need to paint the front covers obviously. I used some black silicone wire insulation from some 14awg wire to cover the led wires and make it look neat.

[wgt40w]

The more I read and follow your Thread, the more I wonder:

How on earth did you get to know so much about not only physical engineering aspects of your builds, but also the workings of all the electronic bits you get involved in ??

[Zeeflyboy]

You presume too much old bean, I pretty much make it all up as I go along...

[wgt40w]

I don't believe you !

[FPVSteve]

Neither do I - you're a man of supreme skill!

Anyway enough smoke blowing - we want mooooaaar updates :D

[Zeeflyboy]

Lol you two. If only you knew the truth... I just think of what I want to do and then figure out a way to do it. Nothing more magical than that I'm afraid!

More updates next week hopefully... Focus is on the cockpit for now.

[g.collins]

I just think of what I want to do and then figure out a way to do it.

Isn't that the way we all do it.
;) G

[wgt40w]

I just think of what I want to do and then figure out a way to do it.

Isn't that the way we all do it.
;) G

Think should have said, "figure out a way where to BUY the answer from".

[Zeeflyboy]

Buying the answer is much easier!


So I thought this was quite neat...

I wanted a visual indication of what Naza mode I am in just for fun. When flying under the goggles I think it'd be possible to mistakenly only select Atti rather than GPS Atti for example, I thought perhaps it would be good to have a reminder of what mode is selected.

So I used another DElight controller which will listen in on the same channel as the mode selector switch... simple matter of programming the correct thresholds for the LED's et voila!

Red - Manual flying: danger Will Robinson, danger.
Yellow - Atti mode: relax Will Robinson, relax.
Green - GPS Atti Mode: who be flying this thing?! Not me...

I can change the mA flowing through the leds using the DElight software so might just turn down the green and yellow slightly though I want to see how it is in daylight first.

I've also been busy on the cockpit and have been making some slow but steady progress - more on that later hopefully...


Mode display switching

[wgt40w]

As ever - just brilliant.

[Zeeflyboy]

Cheers!

Cheers guys!

Another functional thing that will be on the dash is a warning LED for low pack voltage. The Gryphon has an LED module with adjustable voltage warning, so you can control when it comes on.

The idea will be to take the LED feed from that and use it in the dash... It's a last line of defence in case I get too carried away flying to check on the mah burn as that will only be available in the FLIR view. I intend to use the eagletree audio alerts too which will come through no matter which view I'm in!

So, it stopped raining and I just popped out to try my new Spin tail blades.. much better! Way more authority and a better feeling tail - it also behaves much better as regards wagging. Still some tuning to do but now I feel like I have a chance lol...

I was surprised, they actually sound different too - didn't think the tail blades would have that much effect. Very cool effect sometimes as you fly past...

A little more feedback on the Naza unit:

- Still have some right drift in auto modes... Very cloudy crappy day today so probably doesn't help, though it still quickly locked in 6+ sats. In GPS Atti it drifts right a bit, then back again and usually stays out after that... Hoping I can tune this out.

- you have to be careful if you've been flying in GPS Atti and you switch back to manual... In GPS Atti it's very controlled, pretty sedate and big stick movements are required. Manual is still extremely responsive and its easy to over control when switching back. I've already got 40% expo in manual with none in Atti modes, but I need to do more still... I will probably reduce max roll rates in manual mode a little, and add a little negative expo (well, positive in futaba world) to auto modes.

- flying in Atti mode is potentially extremely risky with a heavy helicopter lol. You can build up some serious speed (as opposed to the speed limited GPS Atti mode) but then lack the manoeuvrability to arrest or re-direct all that momentum quickly in the way you can using manual mode.

- it's a blast to fly and still can't get over the sight of the heli hovering so nicely with no inputs.

So, back to work on the cockpit!

[Zeeflyboy]

Just got done painting and assembling my centre console and collective stick...

You can see in the video how it works, but of course the servo was working in the wrong sense. Normally it's no bother - I just open up the servo and switch the motor wires followed by 2 of the 3 potentiometer wires... and this was no different, except that these servos are TINY. I have to reverse the cyclic stick elevator servo too so I might take some pictures as I do so just to show how small it all is.

I was pretty sure I would murder the servo while trying but as it happens it all seemed to work out okay, and now the servo moves in the correct direction to match the pitch commands.

Collective stick test