Originally Posted by luckymacy
How do I troubleshoot an electric plane when I don't have any parts to swap out? I bought a used Sebart Wind 110 I which supposedly has new Hacker A50-16L V2 (it does look shiny new and 'spotless') and the same props, ESC and battery packs that the plane supposedly flew with in copetitions. In other words, it should have been a perfectly working set already installed.
I took it out for a fist flight (for me) today. I had a amp meter installed and was doing a ground check. I do not have any experience with setups this large (8s) so was proceeding extra cautiouslessy. Anytime on the ground I got near 30 amps the motor made a screetch sound and shut down. I removed the back support plate as I was suspicious it was causing some drag/binding but it made no differenc. In my smaller electric planes that's usually been due to overspeeding or not enough load on the motor (ie, the sound doesn't happen when actually flying, it only happens on the ground). I am hoping that the motor won't make that sound and fly fine but I won't risk flying it until I know for sure. Any ideas on how to troubleshoot or verify the setup is fine?
Double check the shaft on that Hacker motor, try rotating the shaft while holding on to the rotating magnet "bell". The shaft is held by a set screw or two. If its loose, it will be obvious.
If the motor is "Bent", it will be visable if you spin the motor either with a battery operated drill, or by just running it with the battery and ESC.
Were you running that motor without a prop? If you had a prop on it, try running it with no prop. (No it won't overspeed, it will just run at its maximum no load RPM.) In fact, running any of my Hacker motors either with or without a prop makes absolutely no difference on how those motors run, while connected to my various Castle Creations ESC's. They run smoothly at any power setting, either with, or without a prop.
Also, is your 6S LiPo in good shape? If you were measuring current, were you also measuring the battery voltage? Also make absolutely certain the three brushless motor wires are solidly connected to the output of the three ESC wires. A loose or intermittent connection here can really screw up things.
What kind or brand of ESC do you have? This does kind of sound like an ESC problem. Make certain your ESC programming isn't allowing the ESC to hit the LVC (Low Voltage Cutoff) on the battery pack.
What is the current/voltage rating on your "Smaller" ESC's and battery? If those ESC's are rated for over 10 or 20 Amps or so, you can try wiring up that Hacker motor to the ESC and battery pack for your smaller models and see what happens. (DON'T USE THE 6S PACK ON YOUR SMALLER ESC!!!! The 6S voltage will blow up your smaller ESC.)
I'm assuming you've not noted any burned smell around the motor and its windings. If it's been overheated and burned up, it will smell like h*ll.
I've got 8 Hacker motors ranging from their A30 size to two A40's, three A50's and two A60's. All run flawlessly. Well one of the A60s had set screws come loose on the shaft and bell housing. After about 170 flights.
You're right, DO NOT FLY this model until you figure out what's wrong. You are dealing with a significant amount of power in your motor/esc/battery setup. And if things go south in flight, you could have a lot of electrical damage, or worse, loose the model on an off field landing or what ever.
And, last, but not least, you might check out my thread on testing brushless motors: