ESC Just Died - could it have been something I've done?

[Tony Smith 7]

Hi,

 

The ESC on my Fun Cub just dropped dead, for no apparent reason.   The motor just cut out, and when I examined it there was no heat anywhere, no smell of burning either.  

 

I powered up in the workshop, no beep from the ESC.  Had a fiddle around,  can't really remember what I touched, then next time I moved the throttle smoke started pouring from the ESC, even with the throttle closed until I pulled the battery.   When I removed the remains it was clearly seriously hot, enough to de-solder the two power leads which came free together with an electrolytic.

 

It was an SP 30A ESC from Giant Cod, the motor is an XYH 35-30 also from GC, with a 10x5 prop.   My thought are ....

 

- I'm thinking it probably didn't die from overload, given lack of heat/smell at the time it failed.

- Maybe something came disconnected internally, then shorted out to create the heat and smoke in the workshop.

 

My questions are firstly does that sound reasonable?   Second does 30A sound a big enough rating for that motor,  and thirdly does the panel think its worth paying a bit more for a better ESC?   Any other comments or suggestions welcome.

 

Thanks in advance, Tony S

[Jonathan Lewzey]

probably just a duff esc. there are a few especially from the cheaper makes. you could answer your amps overload question if you used a wattmeter on the setup before it failed? as for a replacement, i wouldn't spend a huge amount on a jeti or hacker for instance, a medium price, solid unit should do the job, doesn't need to be anything flashy. make sure your motor is working fine too and try to keep wires short rather than long if possible to reduce spikes.

[Stephen Grigg]

I cannot believe you overloaded on a 10X5 prop on the Fun Cub..I use a 12X6 Ive flown  mine since I bought it,Im always taking off  and flying up vertically unti lits nearly  out of  sight,about 30 seconds ,you did nothing wrong mate.I cant tell you what my ESC is the covering fell off!!

[Tony Smith 7]

Cheers.   I'll get another 30A ESC ordered, should be in the air again next week end with any luck.  

[Stephen Grigg]

I just checked the start of the Fun Cub thread and Im using a 40 amp ESC

[Tony Smith 7]

Posted by Stephen Grigg on 12/12/2010 20:19:49:

I just checked the start of the Fun Cub thread and Im using a 40 amp ESC

 With a much more powerful motor, though.

[Engine Doctor]

Hello Tony .if you are intending to stick with electric models then  buy a watt /amp meter that fits between the battery and esc . It will tell you without any doubt or guess work if you a pulling too many amps .it can also save your model as esc failure or fire in flight usually have serious cosequencies to the model  I'd also be inclined to check and see if the motor you used has a dead short as an esc should not fail that quickly even if it si a bit overloaded.

[Barrie Dav 2]

Tony.  Wattmeter.  Important bit of kit.

[Tony Smith 7]

Sorry, I missed the watt meter posts.   I don't have one, but measuring the current isn't a problem,   I hadn't measured properly at full power in this case, firstly because so many people had reported running this sort of combination without problems, secondly because I couldn't be bothered to work out how to restrain the model at full power while still keeping test leads and meter clear of the prop.

 

Even without those tests I'm still remain unconvinced that I was overloading the ESC.   No signs of heat during prior operation and no heat smoke or smell at the time of the failure either.   When it did burn up in the workshop it was on just a whiff of throttle, it burned the moment the motor started turning. 

[paul@scc]

Tony.

How are the motor wires. Do you have them running down the side of the motor? Theres not a lot of room and maybe the wires are touching the spinning motor.

 

On my FC I have the motor wires running out the front and then back through the air scoop.

[Eck]

Hi Tony, I had a similar problem with an XYH 3548/900Kv motor and SP 60A ESC frm the Cod. I'd just fitted the (brand new) ESC to my EFlite Pitts 12, took off, turned into the circuitand the motor stopped fast enough to throw off the prop. I thought that the motor had thrown a magnet, but, on retreival, the motor turned freely enough. The next thought was that it was a duff ESC, but when I went to disconnect it for testing, one of the motor's gold connectors fell off...... These are supplied pre-fitted, so give them a check! The ESC was ruined, but I suspect it was actually the faulty joint wot did it, guv!

[Tony Smith 7]

Posted by paul@scc on 07/01/2011 12:48:29:

Tony.

How are the motor wires. Do you have them running down the side of the motor? Theres not a lot of room and maybe the wires are touching the spinning motor.

 

On my FC I have the motor wires running out the front and then back through the air scoop.

 I'm pretty sure the wires are clear.  They route diagonally so they pass the bell of the motor in the lower left corner of the nose.  Being in the corner gives more clearance.   Ideally I would have taken them vertically down then run back inside the airscoop, but the orientation of the mounting holes on the motor prevent that.

[Tony Smith 7]

Posted by Eck on 07/01/2011 13:16:41:
Hi Tony, I had a similar problem with an XYH 3548/900Kv motor and SP 60A ESC frm the Cod. I'd just fitted the (brand new) ESC to my EFlite Pitts 12, took off, turned into the circuitand the motor stopped fast enough to throw off the prop. I thought that the motor had thrown a magnet, but, on retreival, the motor turned freely enough. The next thought was that it was a duff ESC, but when I went to disconnect it for testing, one of the motor's gold connectors fell off...... These are supplied pre-fitted, so give them a check! The ESC was ruined, but I suspect it was actually the faulty joint wot did it, guv!

That's interesting.  Same make motor and ESC, and when mine failed it also stopped the motor suddenly enough for the prop nut to slacken.   I didn't check the motor wires at the time, but I did a few flights with the new ESC without any problems before the motor itself died.   I'd been thinking that the ESC failure might have damaged the motor, but it could have been the other way round.