Mike Smith Posted February 9, 2017 Share Posted February 9, 2017 I have a problem with a "revving" motor which I am hoping someone may be able to throw some light on. I'm presuming that the issue is with the ESC as this seems the most likely?!?! It's a JP EnErG Pro SBEC 60A programmable brushless ESC. The ESC/motor responds normally for about the first half of the throttle travel. However, any further increase of the throttle control results in the motor revving (a bit like someone revving a car engine) about once a second with no further net increase in the motor speed. In other words the motor alternates between two speeds somewhere around the mid range. After doing this for around 10 or 20 seconds, with the throttle control held steady in the maximum position, the motor speed will ramp up of its own accord, approaching maximum for a few seconds and then drop back to the intermediate speed revving. After a while longer, it will ramp up again for a few seconds, then drop back, etc... etc... The ESC (and the model in which it is fitted) is about 3 years old, but has not been in use for a couple of years and was working perfectly when last used. Cumulative flight time from new is approximately 17 hours. The ESC feeds an Exel EX/3536/1100/7 (1100kv) brushless motor with 10x6 prop and power is from a fully charged 3 cell 2200mAh LiPo. I have tried several different batteries, all with the same results and these batteries all work fine on other models. Control is via a Hitec Aurora 9 TX with Optima 7 receiver. I have removed the ESC to the outside of the model to rule out overheating as a possible cause (although it's never overheated previously). I have also re-calibrated the ESC at max/min throttle positions as per instructions. Has anyone encountered such behaviour from an ESC/motor and, if so, any idea what the problem might be? Thanks in advance, Mike Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 9, 2017 Share Posted February 9, 2017 Was the Tx a couple of years ago, the Aurora and Optima 7 Rx Mike? Quote Link to comment Share on other sites More sharing options...
gangster Posted February 9, 2017 Share Posted February 9, 2017 Very interesting Mike. I have an ACS55 that behaves the same way. I found no cure. But later put it in a model where it was very under run 20 amps max and it still behaves the same way. I will be interested to hear the thoughts of the amassed wisdom. Incidentally the instructions with it and those on the web were in pigeon English but the distributors had the American company name and address in them. Would have thought they could have tidied that up a bit Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 9, 2017 Share Posted February 9, 2017 Mike If it does the same with other batteries then it must either be the ESC, motor or the wiring. 2 years unused can cause all sorts of corrosion related problems. Is this behaviour with the prop on or off? If it behaves normally with the prop off it would suggest the problem is current related and thus most likely to do with the ESC. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 9, 2017 Share Posted February 9, 2017 The easiest way to identify the culprit in these case is by substitution though I would also suspect the esc. It all depends on how accessible the components are but I would take these steps after ensuring all connections are sound and the battery is fully charged: 1: try a different receiver (or, better, a servo tester, which would eliminate the transmitter programming as well) 2:If that shows the same symptoms then try a different esc. If that clears the fault then look at transmitter programming. 3: Replace the motor or esc depending on 2 above. Geoff Quote Link to comment Share on other sites More sharing options...
Mike Smith Posted February 9, 2017 Author Share Posted February 9, 2017 Posted by Denis Watkins on 09/02/2017 16:54:39: Was the Tx a couple of years ago, the Aurora and Optima 7 Rx Mike? Yes, all components now are the same as they were a couple of years ago when it was all working fine. Quote Link to comment Share on other sites More sharing options...
Mike Smith Posted February 9, 2017 Author Share Posted February 9, 2017 Posted by Simon Chaddock on 09/02/2017 16:57:28: Mike If it does the same with other batteries then it must either be the ESC, motor or the wiring. 2 years unused can cause all sorts of corrosion related problems. Is this behaviour with the prop on or off? If it behaves normally with the prop off it would suggest the problem is current related and thus most likely to do with the ESC. It's with the prop on Simon. The model is exactly as it was straight after it's last flight a couple of years ago and it's been stored since indoors in normal temperature/humidity, etc. although I will check all the connections for signs of corrosion. Quote Link to comment Share on other sites More sharing options...
Mike Smith Posted February 9, 2017 Author Share Posted February 9, 2017 Posted by Geoff Sleath on 09/02/2017 17:01:37: The easiest way to identify the culprit in these case is by substitution though I would also suspect the esc. It all depends on how accessible the components are but I would take these steps after ensuring all connections are sound and the battery is fully charged: 1: try a different receiver (or, better, a servo tester, which would eliminate the transmitter programming as well) 2:If that shows the same symptoms then try a different esc. If that clears the fault then look at transmitter programming. 3: Replace the motor or esc depending on 2 above. Geoff Thanks Geoff, that's my next plan but as the installation in this, and my other models, is quite "compact", it's not going to be an easy task, but guess I will have to bite the bullet at some point Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 9, 2017 Share Posted February 9, 2017 7. Heli Governor mode RPM control off First range: Initially there will be a 5 second delay from start to full RPM. After this any further input from the throttle will be as normal. Second range: Initially there will be a 15 second delay from start to full RPM. After this any further input from the throttle will be as normal. Note: If you close the throttle at any point and allow the motor to stop then the time delay will become active again. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 9, 2017 Share Posted February 9, 2017 6. Soft Acceleration Start ups Very Soft – Provides initial slow 1.5 sec ramp-up from start to full rpm intended to protect delicate gears from stripping under instant load. This setting is recommended for either fixed wing models equipped with gearboxes and/or helicopters. Soft Acceleration- Provides initial slow 1 sec ramp-up from start to full rpm. This setting is recommended for either fixed wing models equipped with gearboxes and/or helicopters. Start Acceleration – Provides quick acceleration start ups with a linear throttle response. This is recommended for fixed wing models fitted with direct drive setups. Quote Link to comment Share on other sites More sharing options...
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