Maiden flight = almost instant ESC burnout

[hogster]

Hi Max,

Thanks for your prompt reply, it's really appreciated

It's mounted on four ~12mm M3 hexagonal nylons standoffs, but it's also firmly encased in a plastic box:



I agree about the chicken and egg / motor and vibe problem! I think I will try spinning up each motor and prop in turn, keeping only one prop fitted at a time to see if any are particularly poorly balanced ... The motors, props, motor arms, chassis and AQ are all mechanically hard-mounted to each other, so there's nowhere for the vibes to go unfortunately ...

Do you think my AQ mounting arrangement isn't so good?

Many thanks David

[Max]

Well, it's not on rubber or foam, which is what I was really wondering. Good plan with spinning them up each motor in turn. That can reveal all sorts of interesting things, even besides vibe levels Also do it in pairs (per arm) -- having both going at once could set up a different vibe pattern in the arm/frame, vs. one at a time. Coax setup are definitely more vulnerable to arm flexing/stiffness issues.

One easy way to do this w/out disconnecting anything is to set up a new motor mix in QGC, using only one or two motors, on the port(s) you want to test, and only specify a value for the throttle column (100 or less, rest of the columns at zero). Save that in non-permanent memory on AQ, and when you arm and throttle up, only that (those) motor(s) will spin up, and the speed won't be influenced by the tilt of the frame. It's really quick to test separate motors and combos like that, just change the port number(s) as needed, save to AQ again. You can use a value <100 for the throttle column to limit the max. RPM.

Goes w/out saying, but please be very careful... it's unpleasantly surprising how quickly things can go wrong when rapidly spinning knife blades are involved.

-Max

[Jdmagoo]

[hogster]

Possible development on this topic here:

viewtopic.php?f=33&t=3250&p=21631#p21631

David

[hogster]

Well I'm pleased to say I've now had the maiden flight! More details here:

viewtopic.php?f=33&t=3263#p21891

Unfortunately the ACC levels were through the roof (up to +/- 10!) ... will start another thread for guidance on that though.

I never did find out why those ESCs burned up by the way ... it may have been due to the 5V I was feeding into the red wire on the ESC servo plugs (see thread linked in my previous post), but I'm not sure I'll ever know ...

Thanks David

[LPR]

David

Even with your vibrations you can get the X8 flying by using a lower Tilt angle P but don't try to use any GPS flight modes till your able to have good control in manual mode with default PIDs.

Larry