toto Posted January 14 Share Posted January 14 As many will have read about and maybe commented on my " First taste of The Sky " thread, yesterday my Domino's ESC gave out the Magic Blue Smoke. Weeping I was. ☹️ I've moved the post mortem thread onto a thread of its own rather than fill the above named post with the outpouring of grief. To start off with .... in order to give folks an understanding of the set up .... as it was at the time of the fatality ....... here are a few images of how the various components currently sit. First the motor in an open compartment with no cowl .... then the receiver in the mid section of the fuselage .... and then a few shots of the ESC sitting on top of the battery in the compartment between the motor and the receiver compartments ..... quite full .... another .... and another .... and the money shot that shows just how cramped this is ...... A bit of history ...... Yesterday I was out flying and managed two flighs of around 8 minutes per flight with absolutely no issues what so ever. I stopped after the second flight for a coffee as I do between most flights. There was no signs of heat coming from the ESC or the battery. I had a break of around half an hour then went to change the battery. I switched on the transmitter ... as you do .... then went o plug in the battery and in doing so ...... poof ...... the magic smoke was released from the ESC. I left it for a few minutes then took the gamble to reconnect ... this time .... no magic smoke but when applying the throttle ........ a juddering rattle type noise. I immediately switched off and called it a day. I am about to strip down the ESC and post up photo's of what I find ..... back soon. toto 1 Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 So .... I turned my attention to the ESC itself .... looks pretty good on the face of it ...... I do use one of these deans to EC5 adaptors though .... Hmmmm .... but no signs of burning or arcing etc ..... we move on .... to some real surgery .... I cut off the heatshrink that covers the ESC .... prise of the cover and it looks ok this side ..... aaaaaaa .... what's this I see sneaking out from the bottom edge .... and stinking of a burning smell ..... The culprit I believe ..... better known as " toast " ..... and the underside of the cover that was on top if it .......so .... we now know where it is .... but .... what has caused it. The model complete with the ESC, Receiver, battery and motor was all previously tested using a Watt Meter to see what power and current were being drawn produced etc and all was well. I will need to rescue the original figures data from the Domino post in order to demonstrate. Meanwhile ...... I must do something to bring the Domino back into service. I have no less than 3 more of these Overlander 60A ESC's in stock ..... so it looks like another one goes into service. I also have a Beatles 60A ESC that I could use but the motor connections and battery connections would need to be ordered in to be able to use that. I actually want to go with an other Overlander as I want to see if this would happen for a third time. I will post up with my reinstallation and also look at opportunities to move the ESC to a less crowded and better ventillated position just for the sake of good practice as I don't think the ventillation had any part to play in this instance. I'll be back. toto Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 (edited) So .... The installation of the replacement Overlander 60A ESC ..... I tried installing it to the side of the battery rather than on top .... with the receiver as it was ...... But ...... from a ventillation point of view ..... I think its worse and should probably go to installing it on top of the battery again. what do you think. The only other option would be installing the ESC either lying across the top or the underside of the motor bay but this would be unsightly and offer virtually no protection to the ESC itself. toto next step it to re-run the Watt Meter over the set up which is coming next .... Toto Edited January 14 by toto Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 And the results have come in and the lines are clooooooooosed. Unloaded readings ( no throttle ) 00.00 A 16.60 V 11.10 AP 00.00 W 16.59 VM 184.4 WP 00.0001 AH 00.00 WH and the same but tested under full throttle conditions ..... 39.05 A 15.06 V 43.71 AP 522.70 W 14.90 VM 681.00 WP 00.50 AH 07.80 WH So there we have it ..... drawing 39.05 Amps and with 522.7 W divided by the model weight of approximately 2.8 KG to 6.17lbs = 84.71 Watts per pound. read it and weep. toto Quote Link to comment Share on other sites More sharing options...
kc Posted January 14 Share Posted January 14 Lipos get hot after a flight so putting the ESC on top of the Lipo is likely the cause of the fault. Also ESC needs cooling air so if no air flow then the ESC would be hot already making situation worse. Cure - separate the ESC from Lipo and give it cooling ducts. Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 14 Share Posted January 14 LiPis shouldn't really get hot in normal use - warm, but not hot. Also, there was a cup of coffee consumed between flights so the esc would have cooled down. Finally, it went puff on plugging the LiPo in. Not a cooling issue and toto is looking at moving it because it's good practice. 4 Quote Link to comment Share on other sites More sharing options...
kc Posted January 14 Share Posted January 14 Lipos do get hot in normal use and if they have something -ESC- on top and something - fuselage etc - underneath they have little chance of cooling. Surely the fault - Lipo got overhot and transferred heat to ESC on top which then failed. Failure became obvious when re -connected. Toto should be thinking this was a lucky day - if the ESC provides BEC to Rx then if it had failed in flight the crash would have probably destroyed the whole model! Lucky to escape with just ESC damage. Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 14 Share Posted January 14 It's been proper cold this weekend and for the lipos to have got hot enough to damage the ESC without Toto noticing when taking them out of the model at the end of his flight seems very unlikely. The fact that the ESC failed immediately on connecting the pack for a third flight, with those MOSFETs burning out suggests a fault which is not due to overcurrent with the motor in use, as the throttle was closed and the motor didn't fire up - maybe a dead short somewhere in the ESC or wiring loom - the presence of an adaptor complicates things somewhat. It's also, from memory, the second of these Overlander ESCs that have failed catastrophically in Toto's models. Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 Ok chaps ....... another sort of solution ...... much the same as before but a bit better managed ...... The leads of the ESC ( from motor to ESC ) are not long enough to let the ESC to be sited in the mid-fuselage ..... fact ..... so its either out in front beside the motor or above the battery. The only other alternative .... slight adjustment is as shown below. ESC held onto the underside of the hatch ( above the battery ) with velcro giving a slightly better positioning in that it is held " off " the top of the battery having no direct contact. Admittedly you will be luck if the gap is between 5mm and 10mm. There is ventillation through the pre-formed hole in the back wall fire wall as shown ( not very well ) below .... and from the other side .... this could maybe be improved without risking the integrity of the firewall. The connection between the ESC and Battery for the purpose of changing the battey is still sufficient ..... as follows ...... and connected ...... the other improvement I could make is by either including further ventillation on the top hatch or the underside of the fuselage .... there we have it toto Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 Leccyflyer ..... The first ESC that failed was already goosed when I initially connected it ..... it did not even reach the sky. Immediately on first connection in the shed ...... it started to judder. In my opinion knackered from the start from the point of manufacture. I think they are maybe from a bad batch if that possible. I have done everything possible in terms of ensuring a compatible set up and testing via the Watt meter to try and prove that things are not being pushed to hard .... what else can you do or assume. toto 1 Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted January 14 Share Posted January 14 Having already "goosed" two speed controllers, I think I would want to check out the other common factor, ie, the motor. I would remove the motor connectors and check each of the 3 coils with a multimeter on the resistance setting, including moving the wires around a bit to check if there is an intermittent connection or short. Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted January 14 Share Posted January 14 Hi Toto I recently purchased an overlander 60 ESC via a model shop which failed to work from start Calling overlander help desk they advised me to get it sent back to them due to a recent batch had some internal fault New one works perfectly Say no more 1 Quote Link to comment Share on other sites More sharing options...
PatMc Posted January 14 Share Posted January 14 6 minutes ago, Nick Cripps said: Having already "goosed" two speed controllers, I think I would want to check out the other common factor, ie, the motor. I would remove the motor connectors and check each of the 3 coils with a multimeter on the resistance setting, including moving the wires around a bit to check if there is an intermittent connection or short. I'm afraid testing the coil resistance with a multimeter would tell you nothing. 1 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 14 Share Posted January 14 28 minutes ago, toto said: Leccyflyer ..... The first ESC that failed was already goosed when I initially connected it ..... it did not even reach the sky. Immediately on first connection in the shed ...... it started to judder. In my opinion knackered from the start from the point of manufacture. I think they are maybe from a bad batch if that possible. I have done everything possible in terms of ensuring a compatible set up and testing via the Watt meter to try and prove that things are not being pushed to hard .... what else can you do or assume. toto Understood. TBH the label on the ESC would tell me all I needed to know - I prefer my ESCs not to have the "O" word on there. Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 Hi Keith .... thanks for that. Unfortunately the first ESC, I soldered new connections onto it so I doubt they will entertain that ( as confirmed on the phone by Kings Lynne Models ) and the second I have just dissected so I'm sure they wont wear that either. ..... should this one fail ..... I will try to return that in original condition .... however, thanks for letting me know about your experience ..... worth knowing. Toto Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted January 14 Share Posted January 14 Toto If you think that's bad, take a look at this! This is what I saw when I removed the canopy after landing the aircraft. I had flown the aircraft for 50-60 flights prior to this and neither of the ESCs, motor or flight pack were anything other than slightly warm on landing. There are 2 ESCs in this photo as this is powering a twin outrunner contra motor that you can see on the left. The ESC failed when I was flying towards the downwind end of the aerobatic box and inverted and had just pushed the nose up in order to fly a large half outside loop. There was a sharp crack when the aircraft reached the 4 o'clock position and it seemed to lose all power. Having recovered to level flight it was clear that the aircraft would not make it back to the strip without adding power. I had by this stage closed the throttle. I advance the throttle till I felt the aircraft would make it back at which point a big brown puff of smoke emerged from the fuselage - there is a range of holes on the underside of the fuselage to allow the cooling air out. I got the aircraft back in one piece other than as it was landing across the mown runway the wing tip just caught the long grass and swung the nose in to the grass. As this was at a really low speed I didn't think too much except that when I reached the aircraft it was clear that the port u/c mounting had been broken. Until I was able to examine the innards I had no idea what had happened. When I contacted the ESC manufacturer, he happens to be based in Poland, he said he'd never had an ESC fail before and sent me a new one free. That has worked without any problems since and the original undamaged one has also been faultless. The electronic components in these systems are just picked off the production line. Military Spec electronics come off the same lines, almost always the case, but get a burn in period to check that any failure due to infant mortality is eliminated and to check the performance of the component or chip. They charge the item at ten times, or more, than the commercial item. That's one of the reasons for the high cost of military or civil aviation avionics. No one is going to spend any time in analysing why a component failed as that is just too expensive - unless you are a military or civilian aerospace customer willing to pay the cost of this investigation. Key thing is to have an exit for the cooling air and to feel he temperature of the ESC and flight pack on landing to make sure that they are just warm. Quote Link to comment Share on other sites More sharing options...
toto Posted January 14 Author Share Posted January 14 Thanks for that Peter. Admittedly the ventilation does seem a bit limited so ... even though maybe the root cause .... could be worth increasing it as an additional measure. I have the choice of putting a vent either side of the fuselage or one in the bottom just underneath the battery and the ESC. That maybe tonight's task .... if not tomorrow. Toto Quote Link to comment Share on other sites More sharing options...
kc Posted January 14 Share Posted January 14 I think you should return the 2 failed ESCs and also the remaining unused one and expect a refund on the unused one at the very least. The ESC cannot be used without soldering connectors on so that should not be a reason for failing to replace a faulty item. However if there was no cooling air to yesterdays ESC then they might say that was the cause. Note that the goods should really be returned to the retailer. Possibly Overlander might be interested and sympathetic but it's the retailers responsibility for faulty items. 1 Quote Link to comment Share on other sites More sharing options...
PeterF Posted January 14 Share Posted January 14 1 hour ago, toto said: Ok chaps ....... another sort of solution ...... much the same as before but a bit better managed ...... The leads of the ESC ( from motor to ESC ) are not long enough to let the ESC to be sited in the mid-fuselage ..... fact ..... so its either out in front beside the motor or above the battery. The only other alternative .... slight adjustment is as shown below. ESC held onto the underside of the hatch ( above the battery ) with velcro giving a slightly better positioning in that it is held " off " the top of the battery having no direct contact. Toto, It looks like you have put the Velcro on the flattest side of the ESC with the label. I believe this is wrong and I always have the flattest side open to the air. The flattest side is the heatsink for the FETs, the component that blew in your previous ESC. The heatsink needs to be open to reject heat. You have put Velcro on the heatsink which is a good insulator, a recipe for overheating. If you look at the ESC you dismantled, the one side has various components with a plastic cover to protect them. The other side has the FETs then the thermal heat transfer compound with the heat sink plate. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted January 14 Share Posted January 14 Hi toto, Did the ESC's come with soldered on connections ? Do overlander actually manufacture these units ? in the UK ? Or subcontract ? Or just buy in units and "badge engineer " ??? I would think that if I were overlander I would want to inspect every "returned unit' to try and identify "family faults" and make rectification to manufacture to keep the good company name. Some feel the company does not have a good name ( "O" ) worth protecting ? Contact overlander stating what's happened, twice ? Now, even showing pictures and mentioning this thread. Any batch numbers on the Esc or similar, purchased on same invoice etc. to help overlander ? What guarantee comes with these units ? Yes I know, electric stuff is easily ruined, some even bring non returnable, but if it don't work or dies very early...... I am sure overlander ( two page ad in rcme mag every month ? ) Does not want any bad press etc.. I would be interested to know of their reply and verdict... Common factor, possibly motor, wound in DELTA.... Surely a resistance check would show/suggest something.... Could you show the other side of the Esc PCB board ? Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted January 14 Share Posted January 14 Might be an idea to change the models name, tempting fate a little too much... Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted January 14 Share Posted January 14 Hi Again Toto It's coincidentally that mine came from Kings Lynn Models Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted January 14 Share Posted January 14 Yes, retailer responsible for refund, then they go to manufacturer for a refund... Get the manufacturer/retail supplier involved early.... Mail order shop/UK supplier ( j Perkins ) / manufacturer ( in China ), toprc bf109 mark 2...as an example..... 1 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 14 Share Posted January 14 1 minute ago, Rich Griff said: Yes, retailer responsible for refund, then they go to manufacturer for a refund... Get the manufacturer/retail supplier involved early.... Mail order shop/UK supplier ( j Perkins ) / manufacturer ( in China ), toprc bf109 mark 2...as an example..... Sorry, but if anyone - toto especially - ever needed an example of how not to deal with an equipment problem - whther real or perceived - then your handling of the issues that you said you had with that model is a superb example of what not to do. You could have resolved it in a matter of minutes, but it dragged on for months, with several threads, a huge amount of disinformation and evasion of the simplest of questions and, from what you are hinting, possibly not even fully resolved many months later. 5 Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 14 Share Posted January 14 For those that still believe this is an overheating problem, despite toto explaining the circumstances, this esc is advertised as having overheat protection. Toto is looking at relocating the esc as best practice is to keep it cool. @toto for ultimate cooling, strap it to the motor standoffs - appearance is irrelevant 1 Quote Link to comment Share on other sites More sharing options...
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