Cliff 1959 Posted May 25 Share Posted May 25 A funny thing happened yesterday flying the vintage Mercury IV. I was four minutes into the third flight at about 100ft (fortunately) when the motor started to let out loud beeps and stopped working. I still had servo control so, with the motor continuously beeping, I managed a reasonably good deadstick landing. About five minutes passed as I retrieved the model back to the pits and removed the cowl to examine the esc, the motor was warm and the esc not as much. I reconnected the battery and the motor now ran as normal. The battery still had 60% charge. The motor is a Tornado Thumper bought new for the model, as was the esc, she's flown less than ten flights. The beeping noise is usually associated with a connection problem between the receiver and esc, so is this a clue I wonder? Any ideas guys, should I try a another esc? Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted May 25 Share Posted May 25 (edited) Which motor and ESC? And what arrangements are there to cool the ESC? Could be beeping to tell you that the ESC is overheating. Was there a pattern to the beeping, long and short beeps or pauses? Edited May 25 by Shaun Walsh Quote Link to comment Share on other sites More sharing options...
John Lee Posted May 25 Share Posted May 25 Assuming it is a matching Thumper/Overlander system the sudden continuous bleeps would indicate a voltage supply problem: I'd very carefully check and possibly remake all the power supply connections & also the internal resistance of the battery. Quote Link to comment Share on other sites More sharing options...
RottenRow Posted May 25 Share Posted May 25 Plug a voltage monitor into the battery balance lead. Restrain the model then run it on the ground, with the same battery, for at least the length of time that you were flying it. If / when the fault occurs look at the monitor display, in particular at the balance of the cells. You might see that one has a significantly lower voltage at this point. If so, that indicates a dud cell. The voltages will return to normal once the motor has stopped for a short time. Brian. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 Hi guys, the motor is a Tornado Thumper 4205/06 980w 800kv, the esc is a Overlander XP2 60amp, the battery a 4s 5000mah Turnigy Rapid with about seven charges on it (also used without problems in an edf). The beeps were continuous and fairly rapid, possibly two a second. The esc is on the bulkhead and is directly behind an intake hole in the cowl, the motor control is set to a maximum power of 75% to keep the amp draw to a maximum of 55 amps. The model floats around on about half throttle although I couldn't say what the amp draw is at this setting it must be pretty low, some of the time I'm actually gliding power off. All the power connections were made by me using 4mm gold connectors securely soldered and properly sleeved.the esc to battery connection is an XT90. I'll check connections. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted May 25 Share Posted May 25 13 minutes ago, RottenRow said: Plug a voltage monitor into the battery balance lead. Restrain the model then run it on the ground, with the same battery, for at least the length of time that you were flying it. If / when the fault occurs look at the monitor display, in particular at the balance of the cells. You might see that one has a significantly lower voltage at this point. If so, that indicates a dud cell. The voltages will return to normal once the motor has stopped for a short time. Brian. Sounds like its a low voltage warning and cut off. When you run the motor on the ground monitor the total voltage and individual cell voltages until the motor cuts out as suggested by Cliff. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 7 minutes ago, RottenRow said: Plug a voltage monitor into the battery balance lead. Restrain the model then run it on the ground, with the same battery, for at least the length of time that you were flying it. If / when the fault occurs look at the monitor display, in particular at the balance of the cells. You might see that one has a significantly lower voltage at this point. If so, that indicates a dud cell. The voltages will return to normal once the motor has stopped for a short time. Brian. Hi Brian, from the time the problem started to landing and disconnecting was three minutes, after a further 7:45 seconds I reconnected the motor and it ran normally, (I've just reviewed my video) for the timings. I can try what you suggest, I'll need to charge the battery first though, cheers Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 25 Share Posted May 25 36 minutes ago, Cliff 1959 said: ... the motor control is set to a maximum power of 75% to keep the amp draw to a maximum of 55 amps. How/where do you do this Cliff? most modern escs use continuous training so will assume the last-highest throttle signal is 'full throttle' 🙂 1 Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 11 minutes ago, Phil Green said: How/where do you do this Cliff? most modern escs use continuous training so will assume the last-highest throttle signal is 'full throttle' 🙂 Hi Phil, I set it up on the throttle output on the transmitter, in this case a Radiomaster TX16S, I guess most radios are capable of this. It's just like restricting the amount of travel a servo has (but I'm no expert!), cheers. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 Guys I'm just rendering a video of my garden experiments, I performed individual cells checks as it was running and the problem occurred at three minutes, and to top it all another fault appeared! The motor ran to full throttle before quitting to a tickover then couldn't be shut down without disconnecting the battery! Then I tried a second test without the cowl and after about 90s the motor reset with the usual esc connection sound. The voltages by the way all stayed close together but did drop to about 3.9v per cell. Anyway you'll see the video later on today. Cheers. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted May 25 Share Posted May 25 Cliff, next time you are able, with the model tethered, or with prop off, check the failsafe, as it seems to be going full chat at Brown out. switch the transmitter off with motor running, to see if the motor throttles UP the motor should throttle down of course Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 Here's the video of it happening in the back garden chaps: https://youtu.be/QhJXrBemeqo Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted May 25 Share Posted May 25 I'd say it was an ESC fault, loosing its set-up. It could be a dry joint on the PCB that's being affected by the vibration from the motor. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 1 hour ago, Denis Watkins said: Cliff, next time you are able, with the model tethered, or with prop off, check the failsafe, as it seems to be going full chat at Brown out. switch the transmitter off with motor running, to see if the motor throttles UP the motor should throttle down of course 1 hour ago, Denis Watkins said: Cliff, next time you are able, with the model tethered, or with prop off, check the failsafe, as it seems to be going full chat at Brown out. switch the transmitter off with motor running, to see if the motor throttles UP the motor should throttle down of course Hi Denis, This time it didn't go to full chat just beeped continuously then failed, switched off the tx and it reset the esc but wouldn't run until the tx was switched back on again. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 9 minutes ago, Andy Stephenson said: I'd say it was an ESC fault, loosing its set-up. It could be a dry joint on the PCB that's being affected by the vibration from the motor. Hi Andy, I guess if I swop the esc into another model and put that esc into this model it would identify the faulty component, the esc has been fine up until now but probably less than 10 flights in all, I wonder if it turns out to be the esc can the manufacturer fix it? Quote Link to comment Share on other sites More sharing options...
Geoff S Posted May 25 Share Posted May 25 1 hour ago, Cliff 1959 said: Hi Andy, I guess if I swop the esc into another model and put that esc into this model it would identify the faulty component, the esc has been fine up until now but probably less than 10 flights in all, I wonder if it turns out to be the esc can the manufacturer fix it? I suppose it would be repairable but the manufacturer is most likely in China and it would cost more in time than the price of a new one. The days when I used to repair (valve!) radios back in the late 50s are long gone. You could always remove the heat shrink and closely examine the the PC to find a dry joint but is it worth either the effort or the risk? Moving the esc to another model and seeing if the problem moves with it is a good approach, though. If it proves to be an esc fault then just replace it IMO. There doesn't seem to be an airflow over the esc's heat sink (input but no outlet) so it could be over-heating. If you could only just bear to hold a finger on it was close to 50 degC on the outside - it could be hotter inside, Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 Right, here's the result of trying the esc in a model with the same motor ... six minutes in and hey presto the problem occurred again ... motor died and the esc went back into connection mode with the beeps, closed the throttle and the motor beeped four times and it fired up again, it didn't do this on this deadstick flight though! Perhaps it was a lot hotter. Anyway thanks all for the ideas in conclusion I'll increase the air outlet hole in the cowl and install an 80amp while I'm at it, thanks again, cheers. Quote Link to comment Share on other sites More sharing options...
Cliff 1959 Posted May 25 Author Share Posted May 25 56 minutes ago, Geoff S said: There doesn't seem to be an airflow over the esc's heat sink (input but no outlet) so it could be over-heating. If you could only just bear to hold a finger on it was close to 50 degC on the outside - it could be hotter inside, The outlets are two 'spoons' either side of the cowl, not even as big as the inlet though, cheers Geoff. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted May 25 Share Posted May 25 (edited) Cliff Be aware the throttle effect is achieved by chopping the power on/off. A Watt meter measures the average amps Even at reduced throttle the ESC will still be passing pulses of full power amps. By limiting the average amps to 55 may actually be giving your 60A ESC a hard time causing it to overheat. As pointed out the temperature you feel on the outside of the thick ESC shrink wrap is nothing like that of the working part of the chip buried inside the chip's body. I would favour an ESC with a capacity that can take the full power amps and preferably with some "headroom". After all there is no guarantee that the amp rating printed on the label is 100% accurate. As an aside I take ESC cooling very seriously and even add "fingered" heatsinks as they have several times the heat dissipation capacity of an aluminium plate. I then mount the ESC so the heat sink fingers are on the outside of the fuselage directly in the airflow. The external heatsink fingers on an EDF Maybe overkill but on a cold day you are hard put to feel any warmth from the ESC after a flight but the same can't be said of the battery. Edited May 25 by Simon Chaddock Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 25 Share Posted May 25 4 hours ago, Denis Watkins said: ...as it seems to be going full chat at Brown out. Cant see the logic of that conclusion Dennis 🤔 Why would there be a brownout? and during a brown out the rx wouldn't be feeding a channel pulse to the esc, so the motor would stop. Quote Link to comment Share on other sites More sharing options...
RottenRow Posted May 25 Share Posted May 25 Once you have installed your 80A ESC, it would be interesting to know what the current draw is at 100% (not 75%) throttle setting. It could well be up around that level, seeing that it is 55A at 75% throttle. Rather that limiting the throttle, it would be better to fit a finer pitch prop and use the full range of the throttle setting. Probably something around 75% of the pitch that you are currently using (assuming the same diameter). As Simon suggests, you are probably exceeding the rating of the 60A ESC, the electronic devices within won't like that too much. Brian. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 25 Share Posted May 25 (edited) Just an observation Cliff, in the video you can hear the prop cavitating like crazy, a lower pitch prop would also reduce your current and consequently the heat in the esc, its just a thought... I would check the 3 motor connectors for heat after a failure too (quickly!) 😊 Edit: great minds Brian 😉 Further edit: just to explain my earlier comment, you remember how you used to have to 'train' an ESC to the throttle signal range coming from the rx? unfortunately a modern esc doesnt work that way, they use continuous training which means that if you have your throttle signal limited to 75% (ie about 1.75mS PWM) then it will assume that value is 100% throttle until it sees anything higher than 1.75mS. Going from 75% to 100% you wont see any change in motor speed - its already going at 100% - but as you reduce the throttle, back to (say) 75% the 'new high' value remains and 75% stick becomes 75% motor speed. The ESC trains its max and min to the signal it sees, continuously. Personally I dont like this idea one little bit, but unforch its how most work now! Edited May 25 by Phil Green 1 Quote Link to comment Share on other sites More sharing options...
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