after 5 blown esc's the supplier is still blaming me help needed

[colin watson]

i bought two Align trex 450's at the end of last year one as a back up as i am still learning all was fine the heli built as per instructions but after a number of flights a twitch appeared in the tail. firstly we thought this was either a tail servo or gyro problem after swapping these the problem still persisted. a lot of head scratching and brown trouser moment before the first esc blew so i replaced it with the one from my back up modelthis esc never worked at all. i sent these back to the original supplier who sent them back to the uk agent Robbe. After a number of weeks no answer so i eventually rang Keith at Robbe regarding these to be told it was my fault eventually the shop i bought them from help secure two new esc's at cost £20each +vat &p&p. i had also bought a new one myself the excuse was my soldering not up to standard .

the two new ones were soldered by Robbe the extra one i had purchased i had soldered by a friend of mine who works in electronics. the third esc yes you guessed it blew after a few weeks. i then quarantined the motor and purchased a new motor and fitted one of the esc's supplied from Robbe all was fine everything seemed great then after about 2 months suddenly the 4th esc stopped working so i fitted the 5th one yes again a week or so later you have guessed it. it has blown i sent these three esc's back to Keith at Robbe after contacting him over the problem after about three weeks no answer i contacted Keith again who informed me that he had sent them to Align for there feed back as the Soldering was just acceptable . As you can guess my answer to this as they Robbe had suppied the esc's soldered to me. two weeks ago i asked again for an answer still no answer. i emailed Keith again yesterday now seven weeks since i sent them back no answer. i feel like i am just being ripped off by the uk agent my helis are built and maintained to the highest level i think the problem relates to the motor esc combo and i have been unlucky receiving some sub standard motors or esc's the amp pull was well within the esc's parimeters and these weren't worked hard.

Any advice or help on how i can now resolve this problem greatfully received.

[andy watson]

Trading standards would be my first thought- since I presume we are talking about a reasonable amount of cash here.

[Robert Bromwich]

Hi Colin

Does your trex have a carbon fibre tail boom ?

i had a problem with a eco 8 with one that would make the tail twitch as the static electricity  built up in it.

if this is going to the esc then it could cause the esc to blow

 

rob

Edited By Robert Bromwich on 26/08/2011 22:30:23

[wlfk]

Just to cast a little doubt...

 

If one ESC blows up, chances are it's a manufacturing fault. Or (as I once did) you just spent 8 hours building your 450 then soldered the connectors back to front because you were thoroughly addled.

 

But if you've had 5 go pop, to my mind it either implies that

1) they were from the same batch of duff ESCs or

2) you're doing something wrongly - or there's something about your setup that's caused the ESCs to go pop.

 

I think isolating the motor was very sensible. I trust there's nothing else about the setup (chafing wires against CF frames etc...) that could explain matters? Have you lengthened the wires to or from the ESC? What motor do you have.

 

Do you have particularly power-hungry servos? I presume it was the ESC side that went pop, not the step-down. How hot does your ESC normally get, and do you run a flybarless system? What are your governor / throttle settings?

 

I have to say, I don't see how soldering a plug to the wire could cause the ESC to go bad. I can see how it could make your helicopter fall out of the sky or go up in flames as the connector could either go open or short circuit. But neither of these things would damage the ESC. A motor connector coming loose might, but as I recall these are soldered in position anyway.

 

My best guess (sorry if this seems rough) is that either one of your wires is chafing, causing a short, or you're running a very low throttle setting (e.g. 50%) which is causing your ESC to overheat.

 

 

 

 

[Tim Mackey]

I tend to agree.

[colin watson]

the set up is quite soft no big pitch range but the throttle setting is set at 80% in idle up 1. all servos are standard supplied, all wires are spiro wrapped no chaffing on c/f frames and it has a ali boom. i run a flybar head and the esc didsn't seem to be overheating friends of mine run the same set up with no issues. the gear meshing is per instructions. but what infuriated me was them blaming the soldering yet again even after they soldered them. Flying wise it has been flying lazy eights and hovering only.

[wlfk]

What do you mean when you say 'stopped working?'.

Did the motor still beep on startup? did they go up in flames? Did the servos and receiver still work? Did anything get hot? Are you running governor or normal mode?

 

Another cause for tail twitch is if the low-battery cuttoff is set to trigger at too high a level. As the battery voltage drops, the ESC slows the motor. This reduced load causes the voltage to rise, so the ESC speeds up the motor again, and the cycle continues.

 

I don't know what the problem is, but I still feel it's likely to be at your end rather than the ESCs. ESCs are perhaps the least reliable electrical component - let's say for the sake of argument they have a 5% failure rate. In reality, it's likely to be lower.

 

To get 5 bad ones in a row, you would have 0.05^5 = 1 in 3 million chance. Now, I think Align has sold about that many helicopters so you may be one of the unlucky few, but the chances are still much higher that there's something simply wrong with your setup. I'm not necessarily implying that it's something you've done wrongly - there could be a fault in your receivers or servos.

 

Are you using an UBEC?

 

My next step would be to fit an UBEC (remember to remove the red lead from the ESC to receiver connector) and see whether it's the ESC or the UBEC that fails next.

[colin watson]

when i say stopped working they just stopped starting up didn't bleep nothing the second batch usually showed a tendancy to have difficulty turning the motor before quitting the next time i fitted a battery. i started up in idle 1 with slow start up setting. After i sent off the esc i also removed the 2nd motor and quarantined that one as well. my helis have been checked over by other heli flyers as well. i then ordered and fitted a Scorpion motor and esc replacement which i soldered. guess what not a single glitch in 8 weeks i have various esc's in electric aircraft from aerobatic to edf models and other helis all have been fine. the setting i have been using are mimicked by a friend of mine who has not had a single glitch apart from when he fitted a new tail belt and double crossed it, the esc overheated, cut off and has been perfect ever since. i realise problems on these are as rare as hens teeth its just the dealer Robbe has repeatedly blamed poor soldering in which they soldered the replacements. when i have pressed them regarding these, the response from Keith at Robbe seems to be just ignore me as i have now spent as much as a new heli or more just in esc's and motors with out a real answer.

Edited By colin watson on 31/08/2011 12:31:24

[ross blackwell]

Blimey!I have just set-up 60amp&80 amp esc's & when I hooked up the 60amp unit It played a simple tune but motor would not run:swapped 2 wires still no motor. Moved throttle to high position & waited for music to hit a few notes then moved throttle to idle & every thing seemed O K.How do I change this so that I can start with throttle already on low?This time there was no prop,but I I get the sequence wrong with a prop fitted;wow!

[wlfk]

Have you tried reading the instruction manual? Every ESC is different so we would also need to know what model yours is. If you can't work it out, I suggest you start a new thread as your question is new and not really related to the topic of this thread.

Mostly if you start an ESC with the throttle high, you're entering the programming mode. It could also be that you have the throttle channel reversed, or that you need to change the 'throw' on the throttle channel to get a lower minimum setting.

[ross blackwell]

I hear what your saying but trying to follow instructions on the Turnigy leaflet for me is a bit scary:its a little more confidence building getting another slant on details.

[Steve W-O]

It is possible for poor soldering to cause an ESC to fail, but I don't think that is the problem.

You have a friend in electronics, ask him to measure and note the resistance of the motor windings on both the motors you have had in the machine. You can't do this with an ordinary fluke, you need a milliohm meter.

First thing to check is that the overall reading is within spec, secondly that th three windings all give the same reading.

Then try and measure the no load rpm per volt (kv) of the motors, again check it is within spec.

Then put them in the helicopter, preferably with a much larger temporary ESC, tether the helicopter and check the maximum current at full load (would suggest your 80% throttle with max collective)

The no load rpm and the max current would probably best be measured with a logging device, personally I wouldn't want to get near enough to the helicopter to read an in line meter, UNSAFE to my mind

I'm totally unimpressed with the service you have received, and it may be an idea to send them a letter by recorded post, detailing all the faults, facts, and lack of help you have received in actually finding a solution.

I wonder how much you paid for your machines, compared to how much I paid to buy all the bits from Hobbyking? (I don't really want to know, just making the point about buying genuine and expecting service)

[Dave Bran]

Ross, as has been said, by coming in part way through with a dissimilar problem to the original that has been raised you are risking confusion as answers may be for either problem but maybe not both.....please do not continue here, start a NEW thread with all details!

Colin, for five ESCs to blow it really MUST be a problem with your installation, not inherently the ESC. Yes, the supplier has been rubbish, maybe even clutching at straws, but it does seem to originate as your problem!

Never mind measuring current with meters for now, have you measured the Temperature by feel? Hover for say 30 seconds and land, use throttle cut to make safe, and feel ESC heatsink. Is it any more than lukewarm? It sould not be any more than having the chill off it!

Does the head spin readily withpout resistance in the drive direction with the motor pinion off or backed away so it is not touching the main gear, any undue resistance will load the motor and load the ESC. Is there a small amount of backlash in the motor pinion to main gear mesh? I have seen these pushed so hard in they bind.

I experienced similar symptoms on a friends 500 Heli..in his case the belt was FAR too tight, loading it up............this was actually a dimensional issue, as the boom was fully in both ends!!!

[ross blackwell]

Guess I'm still learning about protocols with the forum Dave:there's just so much stuff to peruse when deciding which spot to land on. Appreciate your advice.

[Steve W-O]

Posted by Dave Bran on 04/05/2012 06:48:35:

Never mind measuring current with meters for now, have you measured the Temperature by feel? Hover for say 30 seconds and land, use throttle cut to make safe, and feel ESC heatsink. Is it any more than lukewarm? It sould not be any more than having the chill off it!

Does the head spin readily withpout resistance in the drive direction with the motor pinion off or backed away so it is not touching the main gear, any undue resistance will load the motor and load the ESC. Is there a small amount of backlash in the motor pinion to main gear mesh? I have seen these pushed so hard in they bind.

I experienced similar symptoms on a friends 500 Heli..in his case the belt was FAR too tight, loading it up............this was actually a dimensional issue, as the boom was fully in both ends!!!

He has said that several other helicopter pilots have checked it out, also said that he has fitted another motor, and everything is fine, so I should think it is a fair assumption the above has been discounted, as they are all basic checks and it is fine with the other motor. All worth checking of course, but unlikely to be missed by several people, or disapear with a different motor.

[David Gilder]

I had a similar problem with my olf Blade 400. I tracked it down to the stock 25a ESC getting to hot.

I quickly solved the problem by upgrading to a 40a ESC and never had a problem since! I personally think that they match them too closely for stock issue in order to try and save a few quid when it would be better to spend another £5 and have a more reliable product!

(thats my 2p worth!)

Dave

[colin watson]

an update on the blown esc's. i replaced the motor and esc in one of the models to a scorpion motor and esc in august last year no problem since the align escs were shipped back to align who have repaired them and sent them back along with one from my 250 heli for which i have blown 3 of as well, the 250 one i fitted back in the heli no adjustment of anything it has been good as gold yet the others lasted 10 flights. i agree with David that these are to closely matched and the repaired ones have better quality fets fitted. it took a lot of emails which eventually got a result on the escs being repaired even after showing them up regarding soldering so service was terrible but the mechanics of the helis are perfect i have now upgraded them to fbl so hopefully they shouldn't be drawing as many amps if you listen to the blurb no spinning flybar