Urgh, so after blowing both of the spare ESCs that I ordered for my DIY Tri project (I originally ordered 5, just to be certain), I ordered two more which arrived yesterday. I excitedly opened things up, soldered up all the wiring, and calibrated each ESC/motor individually. Everything seemed great, very little vibration from the motors, and they respond well without any deadband or lag at low throttle settings. At long last, or so I thought, I was at the point of having a complete tri and ready to start testing things.
I connected the APM outputs to the signal on motors 1 and 2, and the full 3 wire with BEC to motor 4. Throttle high on the Tx, I powered on and off my APM to do an automatic calibration of all three ESCs together. A few beeps from all three arms, all seems good. I pull the lipo off to exit the APM's calibration sequence, throttle to 0, and as soon as I reconnect the battery, yet another sizzle, puff of smoke and an all too familiar little flame shoots out the side of one of the ESCs... :(
That's 3 of 6 that have burned, always at the point where I connect the battery. It's happened with 2 different motors. The 50% failure rate has me wondering if the problem is me... or just the <sarcasm>SPECTACULAR</sarcasm> quality control of certain of HKs products... The motors are rated 11.5A on a 3S (11.1v), and knowing that HK sometimes over rates their ESC performance, I got 25A ESCs to drive them... I was sure I took sufficient precautions to avoid this kind of situation. I didn't run any of the three for more than 4-5 seconds when calibrating.
I don't expect miracles from a 6$ part, but this is really discouraging. Can anyone see any reason why this motor/ESC combination might cause things to be going up in smoke, or am I the victim of notoriously sh*tty QC?
Really? No opinions on this, or is everyone just laughing behind their keyboards at my attempt to get this to work with 6$ speed controllers? lol
What's there to say... I think it's a wrong batch - try writing HK, maybe they know about the problem already and will ship a replacement?
And just a thought - Are your bullet connectors well insulated? Isn't there some kind of short?
The same might as well go for the motors - a faulty motor batch can cause this too.
Thanks for the reply Jan,
I've since had another burn up. The bullets are all shrink-tubed and well separated. One of them that burned happened when the motor was not connected, and I was just using the BEC to power things. I've since ordered 3 jdrones 20a from Dany at Canadadrones, which arrived yesterday. I will fire up the soldering gun again tonight to see.
I haven't asked HK yet, but my understanding of their return policy is that I will have to ship each one, individually, on different RMAs.It would be cheaper to order more, but at this point I think I'm better off to abandon the project, or order more reliable and proven components.
I got things reassembled with 3 jdrones ESCs last night, and for the first time, I was able to get each one calibrated, connected and did an auto calibration with APM. I was able to get all three motors spinning, and even a small attitude response test to see that the motors increased/decreased in RPM appropriately as it was pitched and rolled. I tried a dozen or so times connect the battery, arm, short throttle rev, disarm and power off to see if anything would pop, and things held up.
Looks like I'm going to see if HK is willing to do anything about this... the jdrones 20a ones held up where the HK 25a ones all fried on me.
I stay away from the Hobby King branded stuff, and mostly buy Turnigy. So far so good.
Knock on wood. But I'm sure mine will now blow up next time I plug it in.
s*t happens - even to turnigy stuff. Some HK ESCs are rebranded turnigy I think.
It's like Tesco selling the same stuff Marks&Spencer sold last year for 80% less as "discount", just because there were leftovers :-) And - as with all chinese stuff - quality control doesn't always react as fast as we might like, so good thing they burned still on ground!
And don't forget about all those exploding Castle Creations ESC's. I'm not sure if that ever affected quad-size ESC's, but guys with big helis had a lot of problems. I'm talking.... destroyed the entire model because of the flames.
I'm using those HK SS's on a miniquad, maybe 4hrs flight time and so far so good. They hit about 95-100deg. after 10min of hovering, playing around. It appears using a 3S on the choice of motor maybe pulling too much current--a lot of ESC never like working at their limits for more than 60secs. I'm using a 4S on those escs.
HK blue series are much better. I've got 10hours flight time on one of my quads with them, so far so good. And it works with one of the common "firmware mods" to get rid of the low pass filter (and get better esc response).
On my Arducopter, I've killed a jdrones ESC via the USB/BEC issue (in the old boards), and currently use HobbyWing Pentiums--very good quality and can also apply the firmware mods out there.
Glad to hear they worked out for you. In my case, they would shoot a small flame out the side when I connected the battery, long before I could even attempt to apply any throttle, so they certainly were never driven anywhere near rated max for 60s.
As I expected, HK is willing to replace them only after inspection, requiring me to return each individual ESC separately under separate RMA numbers. A policy which I'm sure is designed to discourage returns s the postage to return it is more than the value of the item.
100deg C or F??
Most ESCs shut down at about 85C I think...