Frank Day Posted September 1 Share Posted September 1 Is there a simple method to discover the spec of a ESC, no label or clue on it. Hope to find out or I may just bin it. Its in a Max thrust Ruckus, they come with a 40A as standard with a 12x6 prop on 3S. For 4S they recommend dropping a prop size. Simple method to me is upping the esc rating especially as I have a few at 50-60-80A rather than faff swapping props back and forth. The model was used and the esc doesnt match those offered by the manufacturer. Obviously just changing it is the safest method but would be interested to know a way of finding its rating. I read about weighing them but as 50a will suit my needs and a quoted +-10A doesnt really help Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted September 1 Share Posted September 1 Frank, if you show us a photo of the ESC, someone might be able to recognise it. Quote Link to comment Share on other sites More sharing options...
Frank Day Posted September 1 Author Share Posted September 1 Hi Robin, I'll grab a picture of it. 8 hours ago, Robin Colbourne said: Frank, if you show us a photo of the ESC, someone might be able to recognise it. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted September 1 Share Posted September 1 Could try comparing the input & output cables of your mystery ESC with others, I don't think any manufacturer would over cable size for no reason, should get you close to its rating. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted September 2 Share Posted September 2 the size of the heatsink is an indication, manufacturers often use the same fets across their range of escs, so the max current spec is arbitrary anyway "test to failure, run at half" is a common acceptance technique 1 Quote Link to comment Share on other sites More sharing options...
simon barr Posted September 2 Share Posted September 2 You can't always just up the ESC ampage size as you may be over amping the motor which will eventually burn out. If you don't know the amp rating of the motor, be careful. 1 2 Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted September 2 Share Posted September 2 9 minutes ago, simon barr said: You can't always just up the ESC ampage size as you may be over amping the motor which will eventually burn out. If you don't know the amp rating of the motor, be careful. Not sure what the current rating of the original motor is. I replaced both the motor and ESC when I uprated my Riot. Quote Link to comment Share on other sites More sharing options...
Dickw Posted September 2 Share Posted September 2 10 minutes ago, simon barr said: You can't always just up the ESC ampage size as you may be over amping the motor which will eventually burn out. If you don't know the amp rating of the motor, be careful. That is not the case! It is the motor that determines how much current it takes, not the ESC. The ESC just has to be big enough to carry the current the motor draws. Dick 7 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted September 2 Share Posted September 2 Why not assume it's a 30A ESC? - run it at 30A (using watts/amps/volts meter) and see how things go, run the motor for at least a couple of minutes. If the ESC only gets moderately warm (out of direct airflow) you're safe. Up the current to 40A and see if the ESC temp rises by very much when still out of direct airflow. If it's OK you could up the current a bit more but do monitor the ESC temp. Anything approaching hot when out of airflow is bad - the interrnal structure of the ESC's MOSFETS will be considerably higher. All a bit of a guessing game so take care and use common sense. Some ESCs have a thermal overload cutout. The old Turnigy 80A units that I have, start to pulse the motor as a warning when they get a bit hot as I found when I pushed my luck on a pusher jet type model some years ago. 1 Quote Link to comment Share on other sites More sharing options...
simon barr Posted September 2 Share Posted September 2 2 hours ago, Dickw said: That is not the case! It is the motor that determines how much current it takes, not the ESC. The ESC just has to be big enough to carry the current the motor draws. Dick Exactly... so larger prop, ups the ampage, motor not rated to new ampage.... burn-out. The new ESC may be able to cope but not the motor. Quote Link to comment Share on other sites More sharing options...
Dickw Posted September 2 Share Posted September 2 35 minutes ago, simon barr said: Exactly... so larger prop, ups the ampage, motor not rated to new ampage.... burn-out. The new ESC may be able to cope but not the motor. Simon I appreciate you understand it correctly, but your previous post gave the impression that increasing the ESC rating increased the current to the motor. A newcomer to "electrics" might be lead into believing that so I just felt clarification was needed, and I hope between us we have achieved that. Dick 1 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted September 3 Share Posted September 3 If you have other ESC is it worth risking a model for ? 3 Quote Link to comment Share on other sites More sharing options...
Frank Day Posted September 4 Author Share Posted September 4 On 03/09/2024 at 09:30, Engine Doctor said: If you have other ESC is it worth risking a model for ? Short answer no. But was asking if there was a simple way to determine its rating. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 4 Share Posted September 4 A very crude "tell" is the number of capacitors. Single capacitor 30A or less. Twin capacitor 40A or more. All my 2-4s ESCs follow this guide but those intended for 6s or above may be different. 2 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted September 5 Share Posted September 5 Very interesting Simon never thought about that. Quote Link to comment Share on other sites More sharing options...
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