Schildere mein Problem mal in englisch, da ich es auch international dikutiere. Solltet natürlich ruhig in deutsch antworten ;-)
Dear Sirs,
Thank you very much for answering my request.
Having a LVC-Trouble was also my first idea, when I heard the engine of my 2,10 m Edge pulsing in the sky (alternating the rpm on a lower level). I thought this, especially because of an used new 2-Blade-Propeller with 22x14. My first 10 flights were with an 3-Blade-Propeller 20x12 and I had no problems at all. At full acceleration my Rotomax 50 pulled 95 Amps out of my 12S5000 Battery-Pack. With the new 2-Blade-Prop it pulled 136 Amps and the problem occured the first time.
But however, after some detailed investigations, I'm thinking that the problem is not the LVC!
I switched again the propeller, installed a smaller 2-Blade-Propeller 22x10. At full acelleration it pulled 82 Amps out of my batteries. But the effect is the same: after about 30 seconds full gas, the Rotomax starts pulsing the rpm on a lower level. And each new time with full gas, this unlikely result is coming a little bit earlier (first at 82 Amps, second at 74 Amps, third at 65 Amps, a.s.o.)
From my side of view, wether the ESC has a malfunction or it is a termical problem. But I'm not sure of what the ESC really does by reaching 100 degrees temperature... normaly it then should completely stop the engine.
How did I programm my ESC?
1. Brake off
2. 12S LiPo
3. Rotation normal
4. Acceleration high
5. Under-Voltage: I tried all three possibilities "Ignore" and "Reduce Power" and "Stop", to check the difference and because of the tones are different from the ESC's user manual! At "Ignore" and "Reduce Power" the result is as described above (pulsing on lower RPM). At "Stop" the engine stops completely when the problem occured.
6. timing: it was on "automatic" already during my first 10 flights with the 3-Blade-Propeller when no problem occured, but as well during my flights with the big Propeller when the problem started. Later I put it on "High", but the problem was still the same.
7. Switching frequency: it was on 8 kHz since my first flights. Later I put it on 16 kHz, but it was not better, the problem still occured.
8. Restore factory setting: never used
9. Active RPM-Controll: never used
I'm having a program box. But I cannot do anything with this box, because it doesn't work at all.
I know, that I have to put 6 V on the box, because of the opto disjunction. But when I do so, in the display of the program box appears only "Hextronik Prog. Box V 0242" and not "...V 1.0" and no push on any key doesn't have any effect! Therefore I did all my programming with the sticks of my transmitter. But by this way I'm not able to controll or change the Cut-off-Voltage!!!
The default should be 3,2V per cell, that makes an effect at 38,4 V by using the 12S Battery.
But the problem occured already higher, at about 42V and because of the installed Graupner HoTT System (incl. Electric Air Module), I'm able to watch all 12 cells in realtime on the 2nd display of my transmitter Graupner MC32, as well as the total voltage, the current, etc. And there was no cell voltage lower than 3,5 Volt and no total voltage lower than 42V when the problem occured! On the other hand should not occure any effect at all, by the already tested program position "ignore" under point 5 on the program list.
While thinking about "what was different during the first 10 flights when it worked corectly", I see only 2 things; first the propeller and second the radio system battery. This little 3S2200 battery got a new position after 10 flights, because of an advantage regarding the Center of Gavity. I put it closer to the Rotomax 50. It could be possible, the the cooling airflow to the ESC is now poor, because this little battery is now between the Rotomax and the ESC. But again, in the case of a temperature problem, the Rotomax should stop immediately, and not starting to reduce power and pulse with a lower RPM.
Hoping that somebody is having further ideas for me?
It's really terrible to have this problem in my favorite airplane, especially during the best summer weeks in the year :-(
Thanks a lot in advance, your support is highly appreciated,
Andreas Meitzke
Phone: +49-(0)177-3228262
Dear Sirs,
Thank you very much for answering my request.
Having a LVC-Trouble was also my first idea, when I heard the engine of my 2,10 m Edge pulsing in the sky (alternating the rpm on a lower level). I thought this, especially because of an used new 2-Blade-Propeller with 22x14. My first 10 flights were with an 3-Blade-Propeller 20x12 and I had no problems at all. At full acceleration my Rotomax 50 pulled 95 Amps out of my 12S5000 Battery-Pack. With the new 2-Blade-Prop it pulled 136 Amps and the problem occured the first time.
But however, after some detailed investigations, I'm thinking that the problem is not the LVC!
I switched again the propeller, installed a smaller 2-Blade-Propeller 22x10. At full acelleration it pulled 82 Amps out of my batteries. But the effect is the same: after about 30 seconds full gas, the Rotomax starts pulsing the rpm on a lower level. And each new time with full gas, this unlikely result is coming a little bit earlier (first at 82 Amps, second at 74 Amps, third at 65 Amps, a.s.o.)
From my side of view, wether the ESC has a malfunction or it is a termical problem. But I'm not sure of what the ESC really does by reaching 100 degrees temperature... normaly it then should completely stop the engine.
How did I programm my ESC?
1. Brake off
2. 12S LiPo
3. Rotation normal
4. Acceleration high
5. Under-Voltage: I tried all three possibilities "Ignore" and "Reduce Power" and "Stop", to check the difference and because of the tones are different from the ESC's user manual! At "Ignore" and "Reduce Power" the result is as described above (pulsing on lower RPM). At "Stop" the engine stops completely when the problem occured.
6. timing: it was on "automatic" already during my first 10 flights with the 3-Blade-Propeller when no problem occured, but as well during my flights with the big Propeller when the problem started. Later I put it on "High", but the problem was still the same.
7. Switching frequency: it was on 8 kHz since my first flights. Later I put it on 16 kHz, but it was not better, the problem still occured.
8. Restore factory setting: never used
9. Active RPM-Controll: never used
I'm having a program box. But I cannot do anything with this box, because it doesn't work at all.
I know, that I have to put 6 V on the box, because of the opto disjunction. But when I do so, in the display of the program box appears only "Hextronik Prog. Box V 0242" and not "...V 1.0" and no push on any key doesn't have any effect! Therefore I did all my programming with the sticks of my transmitter. But by this way I'm not able to controll or change the Cut-off-Voltage!!!
The default should be 3,2V per cell, that makes an effect at 38,4 V by using the 12S Battery.
But the problem occured already higher, at about 42V and because of the installed Graupner HoTT System (incl. Electric Air Module), I'm able to watch all 12 cells in realtime on the 2nd display of my transmitter Graupner MC32, as well as the total voltage, the current, etc. And there was no cell voltage lower than 3,5 Volt and no total voltage lower than 42V when the problem occured! On the other hand should not occure any effect at all, by the already tested program position "ignore" under point 5 on the program list.
While thinking about "what was different during the first 10 flights when it worked corectly", I see only 2 things; first the propeller and second the radio system battery. This little 3S2200 battery got a new position after 10 flights, because of an advantage regarding the Center of Gavity. I put it closer to the Rotomax 50. It could be possible, the the cooling airflow to the ESC is now poor, because this little battery is now between the Rotomax and the ESC. But again, in the case of a temperature problem, the Rotomax should stop immediately, and not starting to reduce power and pulse with a lower RPM.
Hoping that somebody is having further ideas for me?
It's really terrible to have this problem in my favorite airplane, especially during the best summer weeks in the year :-(
Thanks a lot in advance, your support is highly appreciated,
Andreas Meitzke
Phone: +49-(0)177-3228262