Hoverfly Prop Stop

[Emowillcox]

Just finished rebuilding my little X8 hoverfly that made a hard landing a few weeks ago. This machine quickly became the favorite of my fleet in a short time. Over the Christmas holidays I decided to take on my first build with 8 motors after buying a hoverfly pro board. Was pretty impressed with how simple the build was and that I was actually able to put the machine together using instructions that basically came on only 1 page. I mounted 8 tiger 2216 motors with 11x4.7 props, and was using 4 cells. Really surprised at the power the machine made ... added a camera mount with camera. Didn't take long for the Hoverfly X8 machine to remind me of my first love back in the day :livid::nevreness::02.47-tranquillity: which is why when it crashed on me I was pretty upset.

The first time I noticed something I was flying and thought I saw one of the motors really slow down and nearly stop.. like to think i have a pretty keen eye and can often times the the rpm changing on the different motors when I am changing direction.. but this time... I mean rpm was way down and slower on just one motor and I thought it was strange but the x8 kept on flying leading me to believe it was just normal behavior. Few days later I went to fly again and was starting to descend pretty quickly by pulling the throttle back... when again I saw one motor stop.. this time I knew I wasn't seeing things... then a second motor stop.. and before i could throttle up the x8 got side ways and that was it... less then 2 seconds later I was parked in the top of the biggest Oak tree around.

Curious if anyone as any idea what I did wrong with my set up to allow the motors to throttle down and actually stop while descending? I am guessing it has something to do with my throttle set up.. maybe in my radio?
Thanks for the help.

 

[Aerovideo]

First off, sorry for your crash. I know first hand how frustrating that can be. I hope this doesn't sound too basic or insulting but... Did you calibrate the throttle range with your ESCs and Control Radio? (without props) Set the radio to full throttle, plug in the flight battery, hear the two beeps on all the escs then move the throttle to the bottom and hear some confirmation beeps? Sometimes I think it's best to do each ESC one at a time plugged directly into the Rx. That way you know each ESC has been calibrated. Using the all at once method you can't always tell if they all went through the calibration correctly.

Other than that, I'm not sure.

I know I've got a little Eflite Blade MQX quad copter for just flying around. Interestingly enough in extreme maneuvers I can actually see one motor completely shut down. This sometimes results in a crash.

Lastly, I once built a Y6 where one of the motors kept shutting off mid flight. Luckily the HFSport compensated and as long as I was on top of the controls I was okay. Turned out to be an interesting test of redundancy and practice for failure. In the end I tracked it down to a bad solder job on some bullet connectors.

Good luck,
Paul

 

[nicwilke]

Looks like your ESC's are soft shutting off like mine. Perhaps the props are too big and overheating the speed controllers. I had this issue on my X8 and hex, so went from 30A to 40A and fixed the shutoffs. Perhaps you could look into that?

 

[Bartman]

mike

are you sure you calibrated all the ESC's together? if you didn't it might explain why one or two were more willing to shut down when the throttle was pulled way back.

bart

 

[Photronix]

A prop can't stop due to the firmware because we hold a reserve within the software.

 

[Emowillcox]

Thanks guys so much for all the responses. I was leaning towards the throttle issue or ESC calibration, but I think I just learned something very important. Don't build at night after more then 4 beers. I usually can build a quad with in 4 beers, but this X 8 took some extra beer to build. :upset::black_eyed::dread::cold:
Just was cleaning up the wiring from the esc when I noticed that some how I used 4 of the red turnigy plus 40amp esc and I grabbed 4 of the red turnigy plus 25 esc that I was gonna use on another project. They look almost the same just the 40 amp esc are about double as thick as the 25 amp esc.
Actually I am surprised this thing flew at all ... not mention actually flies pretty good.
I'm not a big tech geek so have no idea how this should impact the way the motors handle it, but I can tell it does fly. I imagine that maybe one of the escs would do a softshut down on the motor before the other causing a motor to stop spinning when I was throttling down trying to come down.
Now I need to order some more esc's so I can have them all match. I'll pay attention on calibrating them.
Thank you guys for your replies! Learn something new everyday.