New To Alta8 - Trial By Fire & Some Questions

Discussion in 'ALTA 8' started by Tom Comet, Sep 8, 2018.

  1. Tom Comet

    Tom Comet New Member

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    We have had our A8 for just over a week and have already put it through its paces. Me and my team have been flying heavy lift Aeronavics X8s for over four years now and I have to say, in comparison, we all LOVE the ease of use, functionality and performance of our new A8/MoVI Pro. The fact that we can roll up and be flight ready in less than 15 minutes is truly remarkable. That used to take us 1-2 hours..! I find it amazing how long it flies with a 20# package on 2 X 10,000mah bats and the ease of use and plug and play functionality is brilliant. I did 20+ test flights in all sorts of setups and conditions including SkyView (LOVE IT!) and then went to work... So far we have completed two jobs with our new A8 and both were challenging and somewhat remarkable.

    Job #1 was for a music video (not my favourite gig at the best of times) and the client wanted us to fly a 4 unit array of those 100w StratusLEDs (https://www.stratusleds.com) mounted in the MoVI Pro for directionality and all flown by the A8. Fun! We built a custom frame to hold the LED array and it just fit perfectly inside the MoVI and balanced very well with one 8000mah Tattu bat with nothing blocking the very important heat syncs and cooling fan outputs (those lights get hot!). The timeline was so short that we only had time to get it built and working in the MoVI and didn't get a chance to even test fly the rig at the shop.

    Out to the woods we went for the shoot. Luckily we got to set early and did a very thorough site survey with our new Mavic 2 Pro (very nice machine, I have to say). It was a little nerve-racking flying our very first actual gig with the A8 in the pitch dark up over 30m high trees aiming the high powered LEDs down into the bush to illuminate the band as they ran around like nutters below. I LOVED the A8's orientation lights that night and felt very secure all around. We set a "floor" altitude earlier with the Mavic and gave ourselves a 10m+ safety buffer above the tallest trees to account for any density altitude or altimeter/barometer sensor differences between DJI and Freefly. The shoot went great and the A8/MoVI/Stratus LED combo worked amazingly well and the results on screen looked stunning. The lights made night into day and the flying was relatively easy. Can't wait for the next excuse to put all that together again and shoot a personal project!

    Job #2 was for a big budget TV show that we do regular drone work for here in Toronto. The mission was to launch from the top of a 30 storey building in the heart of downtown in the middle of the night giving a birds eye view of their 2 lead A-list actors from 50'-100' up and out over a closed off square and street below. As luck would have it I had piloted our SkyJib X8 heavy lift package off this same rooftop 2 years earlier on another mission so I wasn't as terrified as I might have been otherwise. This time we were launching from a protruding balcony one storey below the large, flat roof which made for a smaller TO/Landing area but still enough room (15') and lots of sky for GPS capture etc. There were a bunch of steel window washer tracks near our launch site but they didn't mess with our compass and our whole preflight went great. Love that app and the checklists! Nicely done Freefly!

    Of course, the shoot went late and our drone shot got pushed. As the night wore on a cold front rolled in just to the north bringing lots of turbulent air with it. Come game time there were 20km winds but they weren't gusting much at all so I felt OK for a test flight. My Windy app showed exactly what we were experiencing and things were good enough to press on. We did our safety brief, I got confirmation from my Ground Safety that the site below was locked down and then we launched. Sure enough, about 20 seconds after we were airborne out over the 320' high abyss the winds and particularly the wind gusts picked up considerably (25+ km gusts now) and the A8 was pitching all over the place. Terrifying! The MoVI was rock solid but vertical movement was too much for the shot and I just wanted to get the bird back on the ground (roof) to wait out the weather. On the approach to land wind gusts got worse and I had to "head back out to sea" in order to wait it out and hope it calmed before batteries dwindled. Our brand new A8 settled down when it was out and away from the building where it was less turbulent air (buildings always cause weird wind) and we waited. On the next brief wind respite I brought her in and landed quickly with a large sense of relief. I could tell the crew was a little shocked and everyone definitely agreed to delay the drone shot and wait out the weather. Unfortunately the weather just got worse and we had to scrub that mission and go home to try another day. Happily we were going home with our gear in one piece and not multiple pieces in a Home Depot bucket. The A8/MoVI performed admirably even in this very challenging situation and at no point did I feel like we were anywhere near it's limits.

    Questions (some to do with my experiences, some just general):
    -What are others folks advice/experiences with A8 with regards to wind speed and wind gust limitations? Obviously it is all affected by all up weight (AUW), density altitude and battery power (and pilot skill to a degree) but there is nothing in the manual specifically.

    -I fly Futaba with dual RXs on board. If the A8 switches between RXs is there any pilot feedback? It would be good to know as this would be a sign of interference and a higher potential for LOS / RTH.

    -We do a lot of missions downtown in highly contaminated airspace with regards to TX/RX signal. The horizontally mounted "V" antenna holders are nice but I would think vertical profile would be better (or maybe one vertical, one horizontal??).

    -If GPS is not attained (or locked or lost) what does the A8 do during a LOS event?

    -Home Point - does it set automatically on TO and the then can be reset by the pilot afterwards or do I always need to set it manually?

    -Obviously manual flight mode gives best power and response but I see a lot of uses for position and height hold too, especially with those velocity clamps. In position mode our A8 is very slow to move on the cyclic controls (pitch/roll) and speed is reduced (is this a factory setting??). How do I increase the speed in position mode? I would like it higher and then use V-Clamps to reduce.

    -What other performance settings are folks changing for the most part?

    -A MoVI question (wrong forum I know) - I have the pitch and yaw speed switches mapped but the speed changes very little between FULL SPEED and MID SPEED and then it is really, really slow on the LOW SPEED switch setting. I don't see anywhere to change this..??

    Probably lots more questions to come but that's it for now. Loving this new Freefly reality!
     
  2. Wayne Mann

    Wayne Mann Member

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    Hi Tom,

    I also recently acquired an Alta 8 that we use with our Movi Pro and other gimbals.

    On the Movi Pro your pan rate and tilt rate should be mapped to the two dials on the front of the Futaba 14SG. This setup will allow you to tilt or pan very slow to very fast; just by turning the dials. If you prefer to keep the speeds locked together you can assign tilt and pan rate to one dial which will free up a channel in the radio for something else if the need arises. I am assuming that you are using a 14SG for the Movi Pro.

    The Alta's stability in gusty winds with the stock settings is not very impressive to me; especially compared to my other heavy lifters with DJI flight controllers. However if you spend some time on a windy day increasing the gains you can improve it's handling in the wind quite a bit. The other thing that will help a lot is to keep the vibration isolators on the Alta as stiff as possible without causing any vibration issues in your footage. The stiffer the dampers are the more connected the gimbal is to the Alta, giving it more "connected" mass. When the dampers are soft and a gust of wind hits the Alta the gimbal basically stays stationary until the dampers compress to the point where the gimbal has to follow and this makes the Alta very "pitchy" or "twitchy" in the wind. The trick here is that the props and prop assemblies have to be balanced very well to run stiff dampers with lighter payloads. I spent a ton of time balancing the props and the entire prop assemblies to where my machine runs glass smooth. With a Movi Pro, my Panasonic AU-EVA1 and a Canon 16-35mm f2.8 lens which brings the total payload to roughly 12 pounds I can run all black dampers in my Alta in gusty wind with no vibration issues getting to the camera. That makes the Alta behave much better in the wind.

    As for balancing the props and prop assemblies I treat them just like a main rotor or tail rotor assembly on one of my helicopters. Both blades have to weigh the same thing, the spanwise balance has to be the same on both props and then they have to be mounted to the bottom hub and that has to be balanced in a precision balancer.



    Wayne Mann
    www.helicamhighdefmedia.com
     
    #2 Wayne Mann, Sep 8, 2018
    Last edited: Sep 8, 2018
  3. Tom Comet

    Tom Comet New Member

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    Thanks Wayne. Will implement dial control for pan/tilt rate on the MoVI and perform some high wind tuning with the black dampeners in. We are almost always flying at or near max gross weight as we are in film & TV flying cine cameras and lenses with all the extras.
     
  4. Tom Comet

    Tom Comet New Member

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    Oh, and I thought of another question to add to my list:

    -In some of the ALTA Vimeo videos it shows the A8 covered in rain and snow to the extent of water appearing to pool on props, motors and entire top frame assembly. I know multi rotor motors continue to function wet but this looked a little extreme. What are people's experiences with environmental challenges like this?
     
  5. Wayne Mann

    Wayne Mann Member

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    Hi Tom,

    Boy, this forum is really suffering these days.

    I never fly in the rain. Maybe with a small DJI waterproof something. Once rain drops hit the camera lens the shot is over anyway in most cases. I have and would fly in a snow shower as long as the outside temp is below freezing. The Alta is way better protected from moisture than their gimbals are. However the Alta does not have sealed bearings in the motors so dust and moisture can get past the shields which would not be good. At some point down the road I will replace the motor bearings with high quality sealed bearings. Not so much for moisture, but for dust as we often have to fly in very dirty conditions.


    Wayne Mann
    www.helicamhighdefmedia.com
     
  6. Tom Comet

    Tom Comet New Member

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    Thanks for this Wayne. I guess it is just you and me only of this forum...

    Some more questions:

    - What to do in the event of motor failure that results in adverse yaw? Octo's tend to spin when they have a motor failure and in the DJI ecosystem we trained to switch to IOC (intelligent orientation control) and pull straight back on the right stick to bring her back home, even while spinning. A very nice feature indeed! The SYNAPSE FC appears to have no IOC mode. What happens in the event of a motor failure on the A8? I have personally witnessed two motor or ESC failures on heavy lift machines so far and both ended happily due to good training and cool decision making during the emergency.

    -In manual mode OR with no GPS lock what happens in the event of an LOS?
     
  7. Wayne Mann

    Wayne Mann Member

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    Hi Tom,

    Good questions and maybe someone at Freefly will jump in here and provide answers. The only things that I know are what is provided in the user manual. The lack of an IOC mode like DJI has is bad news in the event of a motor failure if you need to "travel" the machine back to a safe landing area. The machine should be able to keep itself level, but directional control is probably out.

    Not sure on your second question. I need to read the manual again to see if it gives any indication of what might happen in that scenario. Indoors and in downtown environments are the most likely places to experience loss of GPS and in a noisy downtown area you stand the chance of loosing both.


    Wayne Mann
    www.helicamhighdefmedia.com
     
  8. Josh Lambeth

    Josh Lambeth Well-Known Member

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    See my thread I just started about the motor out: https://forum.freeflysystems.com/index.php?threads/alta-8-motor-out-event.12747/

    I believe the drone will descend straight down where it is in the event of a LOS without GPS.

    Josh
     

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