One motor suddenly stalling

Hello guys,

I just noticed a weird thing happening on my arducopter. I was doing some tethered testing and the quadrotor seemed to work fine. Then suddenly I could see motor 4 stall and therefore the quadrotor flip. I thought it might be the calibrations so I redid all of that. Then I tied it up again and tested. This time again the motor did it. So I pulled up the logs:

MOT: 1329, 1363, 1306, 1342

ATT, -234, 165, 1768, 407, -157, 20

MOT: 1298, 1378, 1319, 1349

ATT, -143, 276, 1803, 74, -475, 26

MOT: 1332, 1346, 1288, 1382

ATT, -91, 354, 1815, 50, -147, -64

MOT: 1326, 1336, 1329, 1357

ATT, -145, 273, 1811, 307, -247, 45

MOT: 1312, 1372, 1310, 1358

ATT, -229, 169, 1784, 200, -332, 80

MOT: 1327, 1367, 1298, 1364

ATT, -182, 143, 1765, -149, -571, 49

MOT: 1364, 1336, 1285, 1399

ATT, 140, 806, 1939, -653, -1809, -678

MOT: 1351, 1221, 1240, 1600

ATT, 785, 2273, 2584, -1507, -2500, -1057

MOT: 1420, 1207, 1230, 1730

ATT, 1558, 4025, 3207, -1582, -2500, -1369

MOT: 1440, 1207, 1304, 1804

ATT, 2293, 5338, 3825, -2066, -2500, -1686

MOT: 1506, 1207, 1332, 1832

ATT, 3322, 6135, 4695, -2042, -2500, -2103

MOT: 1477, 1207, 1332, 1832

ATT, 4654, 6104, 5832, -2448, -1828, -2500

MOT: 1363, 1207, 1437, 1801

ATT, 7245, 5642, 7332, -2500, -2500, -1355

MOT: 1077, 1077, 1077, 1077

ATT, 10786, 4339, 9601, -2500, -2500, -2005

MOT: 1077, 1077, 1077, 1077

ATT, 14532, 1867, 10747, -2500, -2500, -657

 

If you noticed the last few 'Motor' values suddenly shot up for motor 4 and reached 1800+ which is the max. In reality the motor had stalled... I then stopped the throttle and therefore you see the 1077 values. I need someone better than me to advise on what could be going on here.. Just a history that I didnt really observe this quite frequently. It happens every so often. 

Any ideas?

Thank you

Ammar

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • Thanks Ellison! I ll try switching them around now and see where the problem lies..

    BTW, does anyone know where I can find details on the different logs that I can collect. For example: I am not sure what each of the 8 values PM means. I looked up in the code and it says imu.adc_constraints or dcm.get_health.. However what do these convey??

     

    Similarly for the Atiitude readings, I understand from the code that the first three are roll, pitch and yaw. However I do not know what rc.servo_out is??

  • Those are the PPM values sent to the motor.  It goes up to max because the motor is stalled, and the APM increases the PPM to that motor thinking that side needs more power.  Is the motor or esc that's stalling getting hotter than the others, after this happens?

  • The same thing happened again.... Here are the logs:

    MOT: 1337, 1349, 1381, 1313

    ATT, -61, 156, 1566, 38, -636, 132

    MOT: 1356, 1362, 1270, 1396

    ATT, -113, 181, 1564, 293, 202, -30

    MOT: 1315, 1373, 1370, 1330

    ATT, -164, 173, 1565, 72, -338, 0

    MOT: 1340, 1354, 1314, 1380

    ATT, -125, 224, 1577, -63, -230, 26

    MOT: 1356, 1344, 1323, 1369

    ATT, -78, 328, 1628, -152, -1024, -270

    MOT: 1337, 1307, 1274, 1478

    ATT, 467, 1406, 1981, -1513, -2500, -857

    MOT: 1438, 1207, 1207, 1707

    ATT, 1236, 3081, 2690, -1441, -2500, -1215

    MOT: 1424, 1207, 1272, 1772

    ATT, 2054, 4734, 3406, -1986, -2500, -1653

    MOT: 1485, 1207, 1332, 1832

    ATT, 2891, 5809, 4167, -1733, -2500, -1966

    MOT: 1476, 1207, 1332, 1832

    ATT, 4127, 6120, 5200, -2040, -1944, -2488

    MOT: 1454, 1207, 1444, 1832

    ATT, 5896, 5836, 6439, -2500, -2500, -1079

    MOT: 1383, 1207, 1207, 1597

    ATT, 9294, 4896, 8227, -2500, -2500, -1942

    MOT: 1077, 1077, 1077, 1077

    ATT, 12795, 2901, 9978, -2500, -2500, -1676

    MOT: 1077, 1077, 1077, 1077

    ATT, 16241, 817, 10885, -2500, -2500, 364

     

    Motor 4 gets a really high PWM when it stalls.. What could this be ?

This reply was deleted.

Activity

Neville Rodrigues liked Neville Rodrigues's profile
Jun 30
Santiago Perez liked Santiago Perez's profile
Jun 21
More…