First crash - I guess I'm a "real" drone pilot now

My fault, this one...  Last time I flew a couple months ago I redefined the flight modes so I could try the non-standard ones like circle, etc.  And the way it works - you guys all know this- is that the flight mode switch and the RTL switch combine to give you 6 total modes (3 times 2).  For me to get RTL I'd have to be in mode 3 and then RTL.  But it had been so long I had forgotten that. 

I was flying my last flight only about 15 feet off the ground (grass) and went to try RTL.   But I had forgotten how I had it set up. I was flying in Loiter but the way I had it set up RTL switch sent me to stabilize.  The throttle was low so the thing just dropped out of the sky.  Broke a blue arm and the leg on one of the black arms wrenched out breaking the mount area on the arm.  So 2 new arms....  luckily no harm to gimble or GoPro.

Anyone have a handy dandy way to label or otherwise remember the mode setup when you make changes?

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  • Well, my Iris is back in business!  Since the Pixhawk was making all the right startup sounds and the Pixhawk LED was flashing standby I went back to the real basics and decided to do a radio calibration.  Once I connected MP and went to the radio cal page all the controls responded properly in range EXCEPT throttle and yaw.  They didn't move at all.  So... I opened up the FrSky transmitter and found the connectors for the left stick half unseated.  Then I recalled I was so shocked by the event that I dropped the transmitter in the grass to retrieve my crashed Iris.  Must have been just enough to loosen those connectors.  Anyway, now after an extra disassembly and reassembly I know my way around the insides of Iris.  All is not perfect however.  My ham hands had difficulty reconnecting the main LED plug and I ended up breaking off the connector base from the LED.  Then I figured out how to pop out the lens and pry out the led mounting plate which would have been the best way to reconnect it. I need to get a new one from 3DR... but Iris will fly just fine w/o it in the interim.

  • For my planes and copters I usually create "truth tables" that I print out in paper (so that I can revise them before flying and have them at sight), but you could also create small stickers for your transmitter. This is an example for my X8 copter and Spektrum transmitter:






















    0/1 means up/down in 2-position switches and 0/1/2 means up/middle/down in 3-position switches.

    • Robert, I like that approach.  If only I could get my Iris working again... :-(

  • You should change your throttle mid parameter to match your actual throttle % required to hover.  It will scale the throttle input so that center stick in stabilize provides the actual throttle output required to hover.  That way, switching from an altitude hold mode back to stabilize doesn't result in a sink or climb.

    So lets say in stabilize you actually require 63% throttle to hold a hover.  You know what happens... 50% stick for altitude hold ends up being rather rapid descent when switching back to stabilize.  Set the THR_MID parameter to 630, which represents 63%.  Now in stabilize mode, the stick at 50% will be scaled to 63% actual throttle output.  You can then switch between altitude hold and stabilize without the crazy sink or climb.

  • Well, I got the new arms and swapped them out.  Actually I took it apart Saturday then reassembled it today.  No joy.  Iris won't arm.  It makes all the normal startup sounds and the motors twitch when I hit the ready button.  Then flashing blue light, etc. And I don't even get the uh-uh sound when it fails to arm due to bad GPS or whatever.  Just silence.

     I am doing this indoors with geofence disabled and in stabilize (I have done this before to fly indoors w/o gps).  In any case sicne I am not even getting the no-arm sound something is not right.  One possibilty is the wire sequence.  I took it apart without writing the wire colors down or takign a picture. D'ooohhhh!   I was thinking they were all the same but of course they aren't.  So I lined up the motor wire colors to match the diagonal motor that turns the same way so I *think* I have them right, but sure wouldn't mind seeing a photo or a wiring schematic to confirm.  But not even getting the uh-uh sound is troubling.  Anyone have any ideas?

  • Ray, it seems you followed the labels and that didn't help. :-)

    I'm not very good but I have a simple method that keeps me safe with no extra labels... Especially when the error you describe was at the computer not on the sticks.

    All I do is follow one rule. Double down is RTL. I think double up is loiter as a minor oh shit moment, but the double down rule when programming and flying makes this a non issue...

    Of course right after you hit RTL and realise that huge tree is not programmed to respond to RTL by bending out of the way, you can still have great oh shit moments with RTL too! :-)

    Also, I always check my Android Google chick is connected properly by toggling through the modes and letting her call them out.

    Again I'm just a perma-noob but these keep me feeling comfortable. Then again I don't mind loiter and stabilise and rarely use anything but those and auto. The other thing is follow me, which I still treat as experimental and and super high attention required. Lately I put super simple on ch 7 which has actually been really fun and stable as! So easy even a noob like me can range afar and scare my spotter a bit, one of life's little revenge moments since it's usually the other way around. Look out, she says, OMFG WTF my brain says, am I really that close.... Hehe
    • I switched to a Taranis Tx for this very reason, I'm getting old and my memory stinks.

      Taranis is awesome, It tells me which mode I'm in, the timer announces the time I've been flying every minute and it tells me when it's time to land (based on how long I want to fly) without ever having to look at the TX.

       And this is just the start of what I plan to have it tell me, voltage, current used and present altitude all by flipping a switch is next.

    • Taranis sounds good but I don't think that would have saved me.  I would have had to know the mode I switched to before I flipped the switch.  As low as it was and as fast as it went in there was no time to react.  For now I am just going to use 3 flight modes and keep the RTL switch always going to RTL.

    • Developer

      If you use a GCS or Taranis with spoken modes, you can check your modes before you take off. Fo lighting fast reactions, you need practice ;)

  • I am thinking of maybe usoing some stick on wire label letters, though it would still be hard to show combinations of switch positions.  Maybe the best approach is just to leave it standard and make any necessary changes just before a flight.  Then right back to standard after.

    Got it all apart ready for the new arms.  But I have to give 3DR some demerits on the arm design that requires you to either unsolder or cut the wires to the motors. They surely could and should have desgned them to avoid that extra work.  After all, arm breakages are inevitable.

    The 3 big wires aren't that bad to unsolder and resolder but the little ones are gang soldered together ina tight space.  I cut those mid span and will solder them back there. 

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