Correct me if wrong, but when doing a continuity test (power lead and motor shaft), there should be no reading.....OL.
I posted what I thought was possibly a bad Pixhawk at Arducopter support forum. It had me puzzled because the initial testing didn't reveal any problems with the ESC's/motors. I decided to pull the motors and check the continuity. One was OL (good), the other 12+ M ohms and rising. I'm recalling from electrical class 35 years ago, so be patient with me, but that indicates a bad motor right?
These are KDE 2814XF-515 motors I bought for a Sky Hero Y6 Spy build. I sent one back out of the six for a clicking noise when spinning by hand, and ordered a replacement to continue the build. After assembly, the #5 and #6 motors and ESC's were freaking out much to my dismay.
I should note the ESC's are in the arm tubes and spliced into 1 one wire (12 AWG) for +/- to the PDB to cut down on the spaghetti mess.
Here is my post, unless it got deleted:
http://ardupilot.com/forum/viewtopic.php?f=25&t=10096&p=24650#p24650
Replies
Well, the first motor I sent back was found to have the following issue:
The second motor is confirmed to have a short and will be returned for repair. Although discouraging, I will chalk these incidents up to bad luck at this point and don't consider it a deal breaker for continuing using KDE motors. I've read plenty of posts about T-Motors having problems, so none of them are perfect.
The other determining factor is when first shopping for motors, KDE spent the time in detail answering every question I had. Customer service goes a long way in my book.
Here's a helpful video... https://www.youtube.com/watch?v=7sP3dqRA4js&list=UUfp0-bTQNNDAp...
Thanks for the link, similar to the one I watched. .https://www.youtube.com/watch?v=Hc_1G6aC2sk
I like how the guy in the KDE video says "after a crash or mishap". It's looking to me they need to be tested after purchase and before use. These are brand new motors never having a prop installed, the affected motor has no screws in it at all now, and were not too long to begin with.
http://www.kdedirect.com/ They need to change their statement to "some may be manufactured in the U.S.A" I am not impressed with their Quality Control. I had already sent one motor out of 6 back for a clicking noise while spinning by hand.
At this point I don't trust any of these model motors from KDE. At $72 apiece, I expected better.
Interesting, I was looking at KDE as a potential higher quality replacement to the acclaimed t-motors, but it looks like I need to re think that, thanks for the info DG.
I'm not saying they are bad motors, just that the first one I returned definitely had something wrong internally out the box causing the motor to drag (clicking noise while hand spinning) if the power leads were moved slightly one way or the other.
After finding this motor with a potential short according to KDE's own method of testing for it, I am a bit dismayed. Also, it appears the bad motor may have fried both ESC's on the #5/6 arm. I tested with a known good spare motor from my other copter and the ESC's won't spin the motor.
Yet, if I use a known good ESC the spare works fine. The suspect KDE shorted motor does not work at all on either the spare or new ESC.
KDE replied to my email with this:
I'd like someone to confirm this issue with PIxhawk to make sure I have the wiring correct. I am using the 3DR PM which plugs into the Pixhawk power connector on top, and a UBEC is plugged into the rail on the Aux Out pins.
Thanks.
Here is my power setup per Wiki minus the triple redundancy:
NOTE: I'm using OPTO ESC's. Is my wiring correct?
The only actual test is measuring impedance, resistance alone cannot reveal internal shortcut.