Heya All - First Post but LONG time Lurker/Reader. I have a custom Hex running Arducopter using a Holybro Pixhawk 4. I was using Xing 2814 and Turnigy 5S/51Amp basic ESC’s extremely successfully but always wanted a bit more. 3 weeks ago a motor wouldnt spin and I deduced an ESC had blown so I purchased APD F3 80’s. 2 weeks ago it looked all ok and then it oscillated while yawing and fell out of the sky. I dont have the bin file to share on that one (I thought I downloaded and saved it but I mustnt have).
So I had no 2814’s left and if I was going to spend money I thought I may as well get the Xnova 3220 Cinelifters as replacements. Another crash and I didn’t even have it in the air for more than a couple of minutes while I did quick checks. While gentle yawing an oscillation occured again for a second. Again, while yawing it decided to fall out of the sky - This time only a few meteres off the ground.
I’m at a bit of a loss here and I honestly dont pretend to be an expert - I learn by burning my fingers. Can someone help me here work out what has happened or what I did wrong. It’s birthday month and I ordered a Pixhawk 6C so I could finally to Dshot and telemetry which arrives tomorrow… Was it Vibrations from the motors/props when they picked up speed? I dunno anymore…
Everything looks good, until it doesn’t. When it starts to go wild there’s a real jump in current and drop in voltage. It doesn’t look like a traditional failure where they just go off line. Vibrations look good, and RC inputs look fine.
Just thinking as I type, any chance a prop came loose?
Thank You for the Sanity Check and excellent suggestion - Each motor still has the props very tightly attached (one prop disintegrated upon hitting the ground and 2 motors burnt out/frozen). I’ll strip the frame apart tonight once i re-cut new motor mounts and check EVERY nut/bolt/screw for signs of failure and report back.
Thanking You Kindly Sir.
I read your responses very closely in ALL posts I read and value your very knowledgeable advice.
When I first swapped ESC’s I actually got close to those values as I had significant Z oscillation on first takeoff. ACCZ_P at 0.17 did my because mission planner range indicates .200 - 1.500.
Result was VERY floaty but controllable - It did fall out of the sky as well which I have the onboard video of but sadly no bin to dissect (I have a regimented process for storing but I have failed, probably moved too quick being anxious to see what was broken).
I attempted to “default” a bit after a motor swap which is probably making this harder for me to diagnose.
New FC today - When the new replacement motors arrive again, I’ll report back.
Frame stripped, rebuilt, motors changed the full works. Even updated the firmware on my F3’s which has helped me diagnose the failure point. After the update I didnt think to check motors etc The update reversed all the motors directions (no idea why). On my first test out everything blew in reverse and the downward (upward?) force took out the motor mounts on two opposing sides which I concede I designed poorly and should have had more foresight.
Again, Thank you for the sanity check - I’ve read some interesting stories with the APD F3’s so I was worried I may have been fighting a whole 'nother battle.