Three years later – what happened with the Z84 and iNav?
I have to admit I somewhat lost interest in the Z84 after being disappointed with it’s performance. The inevitable flood of other demands on my time took over and I never got around to documenting my iNav setup and testing.
So what happened? I did setup iNav, had test flights, a few performance issues and few unexpected events too.
On one early test flight a broken RX wire meant the Z84 returned to launch and circled until the battery ran low at which point it landed – this was actually a successful ’emergency’ landing apart from the fact that it happened to land in the top of a tree. Lesson to learn’t here – don’t launch from the edge of the flying field; walk out in to the centre of a nice clear area and launch from there as the launch point will be the centre of the RTL area. Don’t be lazy with this as you’ll regret it if there’s an issue and you have to recover the plane from a tree!
The second unexpected event was really unexplained. Flying around the perimeter of the site I turned around to head home and the video signal dropped out. I presumed due to the change of antenna orientation which isn’t an unusual event with low power FPV video gear. ‘No problem, flick the return to home switch, pop off the FPV goggles and watch her come back’. But she didn’t come back and there was no sign of her – my spotter reporting it went down behind a tree line. After a walk half-way across the park I found the Z84 in more or less one piece. The hatch had popped off and flight pack ejected itself – the camera had come loose too as it was only glues in with hot glue. This crash was unexplained – she was well within RC range with no low RSSI warnings on the telemetry. The flight battery had plenty of power left. Quite disconcerting and the Z84 hasn’t been flown since.
I don’t think the Z84 airframe is well suited to this type of flight. I experienced a lot of instability in the yaw and roll axes if there was any wind – despite some attempts at tuning the PIDs, with no rudder there was little that could be done to fully stabilise it. If I were to put together another iNav (or Ardupilot) package I’d opt for a more traditional airframe.
The Z84 was much more fun flying in manual mode, line of sight, blasting around bank and yank style.
Here’s a video testing flight modes:
And another on a very calm day:
Ultimately I haven’t gone any further in experimenting with iNav installed in another airframe due to limited time and the hassle of complying with increasingly unreasonable regulation aimed at commercialising the lower stratum.
For anyone interested in exploring this for themselves I highly recommend this series on YouTube:
Happy Flying.