I can't get my unit up!

ArduCopter SkyViper
1

My Skyviper can’t get it up.

After having flown the unit successfully for a few weeks including fully automated Mission Planner missions, I had some problems that required taking it back as close to original as I could, including a factory reset. Since then I have recalibrated using the web app via the Sonix. I have also recalibrated using the Mission Planner routines.

In the state that it is currently in, it will not lift more than a few inches from the ground. It will bounce around a few inches up until it gets hung up on some grass and flips over. I am not able to control the direction of drift because any input from the controller causes a pitch or roll motion followed by ground contact. What should I do?

The problem that I mentioned in the first paragraph was a failed motor which was replaced with a generic (aren’t they all) motor from Hobbyking. After that I got a few short flights that reached 20 - 30 ft altitude but had poor altittude and position hold problems so I had it do an auto-tune which improved handling. I then proceeded to do some manual parameter tuning to get back to where I had been happy with the performance. Nothing radical, just adjusting geofence radius and return altitude and things like that.

I have been trying to get it back to normal, including re-soldering the motor replacement splice, and several bouts of reset and re-calibrate with no improvement. I have no logs, for all the good that would do me, because the sd card was ejected without my notice during one of the crashes. I have replaced the card with a 16GB card from PNY witch has been unable to store any of the data or video even though the File System Access does report the presence of a card but with no files. I have been unable to format the card with the app or with Windows10. Must be a card problem.

It is only a short walk to my wit’s end so tomorrow I will just play with the dogs and try to relax.

2

Have you tried flying it in ‘indoor mode’? This could rule out a couple of things.

Also, these quads can have their altitude limited in the software. What is the altitude that the quad is sensing? If it was erroneously reading say 150ft while limited to 130ft it could cause problems.

Also, do you confirm that the motors spin strongly as I suggested in the other thread when doing the motor testing? I would suppose this is okay since you say you’ve flown higher than a couple inches after the motor swap.

Would you mind sharing your parameters? Maybe someone can spot something off.

3

Thanks for your response. I have not tried the test that you suggest yet but I will soon. I did try a takeoff in indoor mode with the same result. I tried several times. What I did try was holding the drone from the bottom so that I was clear of the motors and then doing an arming as if for takeoff. The motors arm normally. I then gave it full throttle and the prop rate increases equally but not greatly as if trying to takeoff. With the throttle held high I then manually rolled and pitched the unit a few degrees in all axes. I could feel the motors react to the change in attitude as if trying to bring it level. I could not tell any real difference in the thrust increase in any individual motor. Within a minute, all props stopped and the LEDs began flashing. I tried it several times with the same response.

4

Thanks for your response. I have not tried the test that you suggest yet but I will soon. I did try a takeoff in indoor mode with the same result. I tried
several times. What I did try was holding the drone from the bottom so that I was clear of the motors and then doing an arming as if for takeoff. The
motors arm normally. I then gave it full throttle and the prop rate increases equally but not greatly as if trying to takeoff. With the throttle held high
I then manually rolled and pitched the unit a few degrees in all axes. I could feel the motors react to the change in attitude as if trying to bring it
level. I could not tell any real difference in the thrust increase in any individual motor. Within a minute, all props stopped and the LEDs began flashing.
I tried it several times with the same response.

I’m guessing one of your motors is bung.

Please grab a log using the web interface - there are pointers on the Wiki
as to how to do that :slight_smile: Upload that log here.

5

Is this the log that you want?

{
“HEARTBEAT” : { “type”: 2 ,“autopilot”: 3 ,“base_mode”: 209 ,“custom_mode”: 2 ,“system_status”: 4 ,“mavlink_version”: 3 ,"_seq" : 176, “_sysid” : 1, “_compid” : 1, “_age” : 498},
“EKF_STATUS_REPORT” : { “flags”: 485 ,“velocity_variance”: 0.000000 ,“pos_horiz_variance”: 0.000413 ,“pos_vert_variance”: 0.013717 ,“compass_variance”: 0.172656 ,“terrain_alt_variance”: 0.008505 ,"_seq" : 222, “_sysid” : 1, “_compid” : 1, “_age” : 118},
“STATUSTEXT” : { “severity”: 6 ,“text”: “EKF2 IMU0 in-flight yaw alignment complete” ,"_seq" : 153, “_sysid” : 1, “_compid” : 1, “_age” : 680},
“SYS_STATUS” : { “onboard_control_sensors_present”: 52558895 ,“onboard_control_sensors_enabled”: 52542511 ,“onboard_control_sensors_health”: 35781679 ,“load”: 459 ,“voltage_battery”: 3838 ,“current_battery”: -1 ,“battery_remaining”: -1 ,“drop_rate_comm”: 0 ,“errors_comm”: 0 ,“errors_count1”: 0 ,“errors_count2”: 0 ,“errors_count3”: 0 ,“errors_count4”: 0 ,"_seq" : 204, “_sysid” : 1, “_compid” : 1, “_age” : 208},
“RC_CHANNELS” : { “time_boot_ms”: 91262 ,“chancount”: 11 ,“chan1_raw”: 1497 ,“chan2_raw”: 1498 ,“chan3_raw”: 1505 ,“chan4_raw”: 1498 ,“chan5_raw”: 1995 ,“chan6_raw”: 1005 ,“chan7_raw”: 1005 ,“chan8_raw”: 198 ,“chan9_raw”: 19 ,“chan10_raw”: 100 ,“chan11_raw”: 22 ,“chan12_raw”: 0 ,“chan13_raw”: 0 ,“chan14_raw”: 0 ,“chan15_raw”: 0 ,“chan16_raw”: 0 ,“chan17_raw”: 0 ,“chan18_raw”: 0 ,“rssi”: 252 ,"_seq" : 213, “_sysid” : 1, “_compid” : 1, “_age” : 190},
“ATTITUDE” : { “time_boot_ms”: 91262 ,“roll”: -0.002145 ,“pitch”: 0.007048 ,“yaw”: 0.097635 ,“rollspeed”: 0.001910 ,“pitchspeed”: 0.000133 ,“yawspeed”: 0.004425 ,"_seq" : 214, “_sysid” : 1, “_compid” : 1, “_age” : 190},
“GPS_RAW_INT” : { “time_usec”: 0 ,“fix_type”: 1 ,“lat”: 290114965 ,“lon”: -821191546 ,“alt”: 44870 ,“eph”: 9999 ,“epv”: 9999 ,“vel”: 0 ,“cog”: 0 ,“satellites_visible”: 0 ,"_seq" : 208, “_sysid” : 1, “_compid” : 1, “_age” : 214},
“RAW_IMU” : { “time_usec”: 91221200 ,“xacc”: 6 ,“yacc”: 3 ,“zacc”: -1001 ,“xgyro”: 0 ,“ygyro”: 0 ,“zgyro”: 5 ,“xmag”: 185 ,“ymag”: -72 ,“zmag”: 361 ,"_seq" : 201, “_sysid” : 1, “_compid” : 1, “_age” : 236},
“SCALED_PRESSURE” : { “time_boot_ms”: 91221 ,“press_abs”: 1012.806 ,“press_diff”: -0.563437 ,“temperature”: 6189 ,"_seq" : 202, “_sysid” : 1, “_compid” : 1, “_age” : 240},
“VFR_HUD” : { “airspeed”: 0.000000 ,“groundspeed”: 0.032176 ,“heading”: 5 ,“throttle”: 0 ,“alt”: 0.000000 ,“climb”: 0.000000 ,"_seq" : 217, “_sysid” : 1, “_compid” : 1, “_age” : 158}}
{
“HEARTBEAT” : { “type”: 2 ,“autopilot”: 3 ,“base_mode”: 209 ,“custom_mode”: 2 ,“system_status”: 4 ,“mavlink_version”: 3 ,"_seq" : 12, “_sysid” : 1, “_compid” : 1, “_age” : 704},
“EKF_STATUS_REPORT” : { “flags”: 485 ,“velocity_variance”: 0.000000 ,“pos_horiz_variance”: 0.000963 ,“pos_vert_variance”: 0.001623 ,“compass_variance”: 0.065639 ,“terrain_alt_variance”: 0.020859 ,"_seq" : 55, “_sysid” : 1, “_compid” : 1, “_age” : 266},
“STATUSTEXT” : { “severity”: 6 ,“text”: “EKF2 IMU0 in-flight yaw alignment complete” ,"_seq" : 153, “_sysid” : 1, “_compid” : 1, “_age” : 1898},
“SYS_STATUS” : { “onboard_control_sensors_present”: 52558895 ,“onboard_control_sensors_enabled”: 52542511 ,“onboard_control_sensors_health”: 52558895 ,“load”: 650 ,“voltage_battery”: 3837 ,“current_battery”: -1 ,“battery_remaining”: -1 ,“drop_rate_comm”: 0 ,“errors_comm”: 0 ,“errors_count1”: 0 ,“errors_count2”: 0 ,“errors_count3”: 0 ,“errors_count4”: 0 ,"_seq" : 59, “_sysid” : 1, “_compid” : 1, “_age” : 170},
“RC_CHANNELS” : { “time_boot_ms”: 92527 ,“chancount”: 11 ,“chan1_raw”: 1497 ,“chan2_raw”: 1497 ,“chan3_raw”: 1505 ,“chan4_raw”: 1498 ,“chan5_raw”: 1995 ,“chan6_raw”: 1005 ,“chan7_raw”: 1005 ,“chan8_raw”: 198 ,“chan9_raw”: 18 ,“chan10_raw”: 98 ,“chan11_raw”: 22 ,“chan12_raw”: 0 ,“chan13_raw”: 0 ,“chan14_raw”: 0 ,“chan15_raw”: 0 ,“chan16_raw”: 0 ,“chan17_raw”: 0 ,“chan18_raw”: 0 ,“rssi”: 252 ,"_seq" : 68, “_sysid” : 1, “_compid” : 1, “_age” : 134},
“ATTITUDE” : { “time_boot_ms”: 92544 ,“roll”: -0.002161 ,“pitch”: 0.006893 ,“yaw”: 0.100758 ,“rollspeed”: 0.004418 ,“pitchspeed”: -0.006084 ,“yawspeed”: 0.016857 ,"_seq" : 69, “_sysid” : 1, “_compid” : 1, “_age” : 134},
“GPS_RAW_INT” : { “time_usec”: 0 ,“fix_type”: 1 ,“lat”: 290114965 ,“lon”: -821191546 ,“alt”: 44870 ,“eph”: 9999 ,“epv”: 9999 ,“vel”: 0 ,“cog”: 0 ,“satellites_visible”: 0 ,"_seq" : 63, “_sysid” : 1, “_compid” : 1, “_age” : 168},
“RAW_IMU” : { “time_usec”: 92442203 ,“xacc”: 12 ,“yacc”: 9 ,“zacc”: -1001 ,“xgyro”: 0 ,“ygyro”: 1 ,“zgyro”: 19 ,“xmag”: 189 ,“ymag”: -79 ,“zmag”: 361 ,"_seq" : 57, “_sysid” : 1, “_compid” : 1, “_age” : 200},
“SCALED_PRESSURE” : { “time_boot_ms”: 92442 ,“press_abs”: 1012.815 ,“press_diff”: -0.554140 ,“temperature”: 6191 ,"_seq" : 58, “_sysid” : 1, “_compid” : 1, “_age” : 200},
“VFR_HUD” : { “airspeed”: 0.000000 ,“groundspeed”: 0.050216 ,“heading”: 5 ,“throttle”: 0 ,“alt”: 0.300000 ,“climb”: 0.020000 ,"_seq" : 72, “_sysid” : 1, “_compid” : 1, “_age” : 10}}
{
“HEARTBEAT” : { “type”: 2 ,“autopilot”: 3 ,“base_mode”: 209 ,“custom_mode”: 2 ,“system_status”: 4 ,“mavlink_version”: 3 ,"_seq" : 110, “_sysid” : 1, “_compid” : 1, “_age” : 920},
“EKF_STATUS_REPORT” : { “flags”: 485 ,“velocity_variance”: 0.000000 ,“pos_horiz_variance”: 0.001786 ,“pos_vert_variance”: 0.008805 ,“compass_variance”: 0.040032 ,“terrain_alt_variance”: 0.024089 ,"_seq" : 175, “_sysid” : 1, “_compid” : 1, “_age” : 198},
“STATUSTEXT” : { “severity”: 6 ,“text”: “EKF2 IMU0 in-flight yaw alignment complete” ,"_seq" : 153, “_sysid” : 1, “_compid” : 1, “_age” : 3194},
“SYS_STATUS” : { “onboard_control_sensors_present”: 52558895 ,“onboard_control_sensors_enabled”: 52542511 ,“onboard_control_sensors_health”: 35781679 ,“load”: 408 ,“voltage_battery”: 3830 ,“current_battery”: -1 ,“battery_remaining”: -1 ,“drop_rate_comm”: 0 ,“errors_comm”: 0 ,“errors_count1”: 0 ,“errors_count2”: 0 ,“errors_count3”: 0 ,“errors_count4”: 0 ,"_seq" : 186, “_sysid” : 1, “_compid” : 1, “_age” : 40},
“RC_CHANNELS” : { “time_boot_ms”: 93785 ,“chancount”: 11 ,“chan1_raw”: 1497 ,“chan2_raw”: 1497 ,“chan3_raw”: 1507 ,“chan4_raw”: 1498 ,“chan5_raw”: 1995 ,“chan6_raw”: 1005 ,“chan7_raw”: 1005 ,“chan8_raw”: 198 ,“chan9_raw”: 18 ,“chan10_raw”: 99 ,“chan11_raw”: 22 ,“chan12_raw”: 0 ,“chan13_raw”: 0 ,“chan14_raw”: 0 ,“chan15_raw”: 0 ,“chan16_raw”: 0 ,“chan17_raw”: 0 ,“chan18_raw”: 0 ,“rssi”: 252 ,"_seq" : 179, “_sysid” : 1, “_compid” : 1, “_age” : 174},
“ATTITUDE” : { “time_boot_ms”: 93785 ,“roll”: -0.001872 ,“pitch”: 0.007238 ,“yaw”: 0.104383 ,“rollspeed”: -0.002858 ,“pitchspeed”: 0.002378 ,“yawspeed”: -0.030122 ,"_seq" : 180, “_sysid” : 1, “_compid” : 1, “_age” : 164},
“GPS_RAW_INT” : { “time_usec”: 0 ,“fix_type”: 1 ,“lat”: 290114965 ,“lon”: -821191546 ,“alt”: 44870 ,“eph”: 9999 ,“epv”: 9999 ,“vel”: 0 ,“cog”: 0 ,“satellites_visible”: 0 ,"_seq" : 190, “_sysid” : 1, “_compid” : 1, “_age” : 44},
“RAW_IMU” : { “time_usec”: 93905326 ,“xacc”: 8 ,“yacc”: 2 ,“zacc”: -999 ,“xgyro”: 2 ,“ygyro”: 0 ,“zgyro”: 17 ,“xmag”: 203 ,“ymag”: -85 ,“zmag”: 361 ,"_seq" : 183, “_sysid” : 1, “_compid” : 1, “_age” : 58},
“SCALED_PRESSURE” : { “time_boot_ms”: 93905 ,“press_abs”: 1012.808 ,“press_diff”: -0.561406 ,“temperature”: 6193 ,"_seq" : 184, “_sysid” : 1, “_compid” : 1, “_age” : 58},
“VFR_HUD” : { “airspeed”: 0.000000 ,“groundspeed”: 0.061495 ,“heading”: 5 ,“throttle”: 0 ,“alt”: 0.230000 ,“climb”: 0.020000 ,"_seq" : 170, “_sysid” : 1, “_compid” : 1, “_age” : 222}}
{
“HEARTBEAT” : { “type”: 2 ,“autopilot”: 3 ,“base_mode”: 209 ,“custom_mode”: 2 ,“system_status”: 4 ,“mavlink_version”: 3 ,"_seq" : 28, “_sysid” : 1, “_compid” : 1, “_age” : 246},
“EKF_STATUS_REPORT” : { “flags”: 485 ,“velocity_variance”: 0.000000 ,“pos_horiz_variance”: 0.002779 ,“pos_vert_variance”: 0.002033 ,“compass_variance”: 0.054735 ,“terrain_alt_variance”: 0.027475 ,"_seq" : 43, “_sysid” : 1, “_compid” : 1, “_age” : 126},
“STATUSTEXT” : { “severity”: 6 ,“text”: “EKF2 IMU0 in-flight yaw alignment complete” ,"_seq" : 153, “_sysid” : 1, “_compid” : 1, “_age” : 4502},
“SYS_STATUS” : { “onboard_control_sensors_present”: 52558895 ,“onboard_control_sensors_enabled”: 52542511 ,“onboard_control_sensors_health”: 35781679 ,“load”: 426 ,“voltage_battery”: 3823 ,“current_battery”: -1 ,“battery_remaining”: -1 ,“drop_rate_comm”: 0 ,“errors_comm”: 0 ,“errors_count1”: 0 ,“errors_count2”: 0 ,“errors_count3”: 0 ,“errors_count4”: 0 ,"_seq" : 45, “_sysid” : 1, “_compid” : 1, “_age” : 128},
“RC_CHANNELS” : { “time_boot_ms”: 95040 ,“chancount”: 11 ,“chan1_raw”: 1497 ,“chan2_raw”: 1498 ,“chan3_raw”: 1396 ,“chan4_raw”: 1498 ,“chan5_raw”: 1995 ,“chan6_raw”: 1005 ,“chan7_raw”: 1005 ,“chan8_raw”: 198 ,“chan9_raw”: 18 ,“chan10_raw”: 97 ,“chan11_raw”: 22 ,“chan12_raw”: 0 ,“chan13_raw”: 0 ,“chan14_raw”: 0 ,“chan15_raw”: 0 ,“chan16_raw”: 0 ,“chan17_raw”: 0 ,“chan18_raw”: 0 ,“rssi”: 252 ,"_seq" : 31, “_sysid” : 1, “_compid” : 1, “_age” : 232},
“ATTITUDE” : { “time_boot_ms”: 95040 ,“roll”: -0.001522 ,“pitch”: 0.006975 ,“yaw”: 0.104731 ,“rollspeed”: 0.006516 ,“pitchspeed”: 0.007429 ,“yawspeed”: -0.006170 ,"_seq" : 32, “_sysid” : 1, “_compid” : 1, “_age” : 234},
“GPS_RAW_INT” : { “time_usec”: 0 ,“fix_type”: 1 ,“lat”: 290114965 ,“lon”: -821191546 ,“alt”: 44870 ,“eph”: 9999 ,“epv”: 9999 ,“vel”: 0 ,“cog”: 0 ,“satellites_visible”: 0 ,"_seq" : 49, “_sysid” : 1, “_compid” : 1, “_age” : 134},
“RAW_IMU” : { “time_usec”: 95121503 ,“xacc”: 3 ,“yacc”: 2 ,“zacc”: -1002 ,“xgyro”: 3 ,“ygyro”: -6 ,“zgyro”: 0 ,“xmag”: 186 ,“ymag”: -92 ,“zmag”: 362 ,"_seq" : 35, “_sysid” : 1, “_compid” : 1, “_age” : 158},
“SCALED_PRESSURE” : { “time_boot_ms”: 95121 ,“press_abs”: 1012.819 ,“press_diff”: -0.550390 ,“temperature”: 6195 ,"_seq" : 36, “_sysid” : 1, “_compid” : 1, “_age” : 156},
“VFR_HUD” : { “airspeed”: 0.000000 ,“groundspeed”: 0.087087 ,“heading”: 6 ,“throttle”: 0 ,“alt”: 0.190000 ,“climb”: 0.020000 ,"_seq" : 37, “_sysid” : 1, “_compid” : 1, “_age” : 158}}
{
“HEARTBEAT” : { “type”: 2 ,“autopilot”: 3 ,“base_mode”: 209 ,“custom_mode”: 2 ,“system_status”: 4 ,“mavlink_version”: 3 ,"_seq" : 119, “_sysid” : 1, “_compid” : 1, “_age” : 562},
“EKF_STATUS_REPORT” : { “flags”: 485 ,“velocity_variance”: 0.000000 ,“pos_horiz_variance”: 0.003537 ,“pos_vert_variance”: 0.003506 ,“compass_variance”: 0.059958 ,“terrain_alt_variance”: 0.025636 ,"_seq" : 162, “_sysid” : 1, “_compid” : 1, “_age” : 108},
“STATUSTEXT” : { “severity”: 6 ,“text”: “Tmode: throttle disarm” ,"_seq" : 156, “_sysid” : 1, “_compid” : 1, “_age” : 140},
“SYS_STATUS” : { “onboard_control_sensors_present”: 52558895 ,“onboard_control_sensors_enabled”: 52542511 ,“onboard_control_sensors_health”: 35781679 ,“load”: 428 ,“voltage_battery”: 3817 ,“current_battery”: -1 ,“battery_remaining”: -1 ,“drop_rate_comm”: 0 ,“errors_comm”: 0 ,“errors_count1”: 0 ,“errors_count2”: 0 ,“errors_count3”: 0 ,“errors_count4”: 0 ,"_seq" : 149, “_sysid” : 1, “_compid” : 1, “_age” : 226},
“RC_CHANNELS” : { “time_boot_ms”: 96532 ,“chancount”: 11 ,“chan1_raw”: 1497 ,“chan2_raw”: 1498 ,“chan3_raw”: 1148 ,“chan4_raw”: 1498 ,“chan5_raw”: 1995 ,“chan6_raw”: 1005 ,“chan7_raw”: 1005 ,“chan8_raw”: 198 ,“chan9_raw”: 19 ,“chan10_raw”: 99 ,“chan11_raw”: 22 ,“chan12_raw”: 0 ,“chan13_raw”: 0 ,“chan14_raw”: 0 ,“chan15_raw”: 0 ,“chan16_raw”: 0 ,“chan17_raw”: 0 ,“chan18_raw”: 0 ,“rssi”: 252 ,"_seq" : 166, “_sysid” : 1, “_compid” : 1, “_age” : 66},
“ATTITUDE” : { “time_boot_ms”: 96533 ,“roll”: -0.000983 ,“pitch”: 0.006381 ,“yaw”: 0.104455 ,“rollspeed”: 0.013178 ,“pitchspeed”: 0.009765 ,“yawspeed”: 0.007722 ,"_seq" : 167, “_sysid” : 1, “_compid” : 1, “_age” : 66},
“GPS_RAW_INT” : { “time_usec”: 0 ,“fix_type”: 1 ,“lat”: 290114965 ,“lon”: -821191546 ,“alt”: 44870 ,“eph”: 9999 ,“epv”: 9999 ,“vel”: 0 ,“cog”: 0 ,“satellites_visible”: 0 ,"_seq" : 153, “_sysid” : 1, “_compid” : 1, “_age” : 232},
“RAW_IMU” : { “time_usec”: 96593162 ,“xacc”: 8 ,“yacc”: 9 ,“zacc”: -998 ,“xgyro”: 2 ,“ygyro”: -6 ,“zgyro”: 10 ,“xmag”: 202 ,“ymag”: -40 ,“zmag”: 364 ,"_seq" : 170, “_sysid” : 1, “_compid” : 1, “_age” : 10},
“SCALED_PRESSURE” : { “time_boot_ms”: 96593 ,“press_abs”: 1012.811 ,“press_diff”: -0.558125 ,“temperature”: 6197 ,"_seq" : 171, “_sysid” : 1, “_compid” : 1, “_age” : 10},
“VFR_HUD” : { “airspeed”: 0.000000 ,“groundspeed”: 0.091188 ,“heading”: 6 ,“throttle”: 0 ,“alt”: 0.170000 ,“climb”: 0.010000 ,"_seq" : 157, “_sysid” : 1, “_compid” : 1, “_age” : 124}}

Sent from my iPhone

6

Its UP! I finally got around to running the 100 percent power motor test. It was very clear that one of the motors did not match the others in power. It was the one that I had just replaced. I had bought a set of 4 so I still had one with the right rotation/ I did a quick replacement and a quick cllibration and took it out to try. It is very windy so I kept it below 20 feet. POS_HOLD and ALT_HOLD were a little uncertain but it responded well to stick commands so I will wai for a better day to get it trimmed up.

Lesson learned. These little motors can go half bad. I had not expected that. I thought these brushed motors worked or not. The first replacement had provided two or three flights before it went half bad. The 100 percent power test is a quick and easy way to find out. Thanks for all of your help.

7

Very nice to hear, if you’re curious you could spin the motor around by hand while testing for continuity/resistance in the motor windings and make sure that all positions have the same resistance and all do have continuity. If you’re a bit better equipped throw it on a power supply with an oscilloscope.

8

I don’t have much in the way of electronics test equipment, in fact none. Well maybe a DVM and a soldering iron. I do have a fairly well equipped machine shop but thats from another day. As to further testing on that motor. Not very likely. I consider anything that costs less than 3 dollars to be unrepairable. Just for curiosity, I disassembled the first motor, or I should say demolished, the first bad motor. I am convinced that it is next to impossible to open one of these things and put it back together reliably. These things are an amazing piece of design and manufacturing but they are disposable. They are also in a sense, very crude. The commutator is nothing more than the bare ends of the armature winding glued to a plastic core. The brushes are just very thin metal strips imbeded in the plastic structure of the end cap and held in contact with the “commutator” by the tension of their own flex. They last a few hours and are not able to take any stresses, particularly high current caused by a hard stall.

It is hard to imagine a better example of meeting the design parameters for the intended application. Easily repairable is not one of those parameters. This one is 8.5mm diameter. I think they are made smaller than 6mm diameter. I would really like to see the equipment that creates that coreless armature. The Chinese must have developed a copper based silkworm for the job.

3 Likes