Old Fogey Disaster! Almost!

[ViperTech]

Super calm weather here in PA! So I took the Old Fogey along to the field tonight and was just having a lovely cruise around when the motor stopped, I still had control and was high enough to land it, thats when things got ugly. Smoke was just pouring out of the fuse and man what a smell! I disconnected the battery that wasn't the problem! Yanked the pod out and there it was! ESC fried to a crisp!:black_eyed:

Really not sure what happened the motor turns freely and I was just cruising along, this is a Grayson Hobby combo unit.


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Thankfully the plane is still intact and will fly again!
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[TTMR]

Likely a short somewhere, either in the ESC or in the motor/leads. Glad you got your plane down safe!

 

[felixx]

nice recovery
I was practicing dead stick landings today

this sort of story scares me

 

[Craftydan]

Hate to say it -- most everything else I've bought from them is excellent, service and all -- but the Grayson 18 ESCs are crap. they're re-branded Redbrick's, and I've had one fry, just as you describe on an idling tricopter, and another get a taste for eating motors (plug in the ESC, the motor *immediately* starts smoking).

That being said, I'd check that motor *VERY* carefully -- pull the retaining clip off the back and disassemble it -- and inspect the coils. also check resistance across the three motor poles. Any discoloration on the wires or unbalanced resistance across he three poles, count the motor as toast and expect it'll do the same to the next ESC you plug in. Otherwise . . . best of luck with the next ESC . . .

 

[ViperTech]

Craftydan, I have pulled several motor apart to change the bent shafts but have never done any diagnostics on the wires. You say check the resistance across the 3 poles, Correct me if I am wrong, I assume that the wires are coated and there should be infinity between the poles and I would think that the same applies with the poles to the housing! Thanks for the advice and help. Oh, the motor spins freely and smooth, so no bearing issues.

 

[joshuabardwell]

There should be no continuity between the poles. If you get anything other than infinite resistance, I think it means you have a short in your motor.

 

[Craftydan]

Viper,

Sorry, I don't mean the poles on the stator, but the electrical poles -- the three power connections (my poor choice of words ). The brushless motors are small 3-phase motors, and whether they're wired in Y or delta, the resistance between the three should be constant. A broken or damaged phase would show up in 2 of the three resistances being different than the third.

You are correct, the stator and bell should be electrically isolated. Good to hear the bearings are in good shape. Hopefully the coils are too and you're only out a cheap ESC.

 

[MartyLJ57]

So, for the newbie like me, when building the swappable motor pod what should we look out for. Jash B. Mentioned in his simple Soarer video he said you don't need a ESC when you go to the motor version. Is that correct.

 

[xuzme720]

No, you definitely need an Electronic Speed Controller for controlling the motor. If you are building a glide only (no motor) version, you can use either a BEC (a Battery Elimination Circuit) or an ESC with the motor leads isolated and insulated so they don't short together. Either will supply the needed 5-6 volts the servos and Rx needs. Or you can go with a purposed receiver battery...