Hello friends! Once again i call upon this great community to help with an issue i don't understand. I just returned from a job where my Cinestar 8 performed a great job. we were in all corners of the world without an issue... Well, until the last shot of the last day. I just finished filming a scene without any hint of problems. After a quick battery change, all motors did their usual chirp on start up. I then increase my throttle to take off, and my number 6 motor wont spin. It will spin one revolution and stop, and continue to do so. I check my settings, all good, I check my esc and have a green light, I test my spare motor and the same thing happens. I then check my flight log and nothing. No errors nothing unusual. On my return to the hotel I decide to test again. This time the copter starts up fine. I do a low altitude test flight and she fly's great. Now im back home and the same thing is going on, but im not showing any errors on my bl's/ esc Does anyone have any idea what might be causing this intermittent problem. I cant fly bird until i know whats going on and i have some jobs coming up. Cinestar 8 MK flight crl 2.1 Navi crl 2.0 Any help would be greatly appreciated.
Hey Darren the only thing I can think of is that one of your motor wires connectors might have a bad connection. Like a bad bullet connector not full having full contact? can you show us what type of motor connector you are running? Have you tried switching the motors over to another bl to see what happens?
Hi Jason, Thank you for your reply. Yes, i switched it over and it works fine. I know its not the motor but i guess it could be the connection from the bl to the motor. I don't see any visible damage and it is a pretty tight connection.
Yeah If its those split type connectors like the t-motors have you can always just get screwdriver and make them more open to make 100% sure there get connected.
Another thing i noticed is that the wires between the esc's and the motor wires are actually getting hotter than the others even though the motor is not fully spinning.
Darren can might want to give us you more info on your set-up motors props etc. Maybe give us a gpx file with the problem then maybe someone can dial in?
There is no Gpx file because I can't take off. And the last flight it took before this problem didn't show any problems as far as I can tell.
You dont need to take off to get a gpx file. Just take your props off and start your motors Make sure you run it for about 1 min and move your sticks around so we can see if anything is abnormal
The GPX file will start recording when the throttle exceeds 40%. The other candidates for the problem include: 1. Check the solder connection on the BL-Ctrl in question. Perhaps re-flow the solder to ensure it's good. 2. The BL-Ctrl has itself failed -- the green LED is not an absolute guarantee. The symptoms you're getting suggest that the three phase power to the motor is not being supplied -- either it's getting there as two phase, or the BL-Ctrl is failing to provide adequate current (my hunch is on the two-phase theory). If it's 2. above, then you may have to replace the BL-Ctrl itself. Dave King did this and posted a video on this topic so it might be worth a search for that. Andy.
Thank you Andy. The copter is on my table without props on. I guess what i meant to say is that i can start all motors besides #6 and therefore it wont let me use any throttle to initiate the gpx recording. It will only sit on idle speed. All connections look solid and there is no indication of anything abnormal. Is there a simple test i can do to confirm it is the BL Ctrl failing? they are all pretty new. I have had an issue with 2 in the past and had the whole unit replaced.
Do you see any kind of error indication when you connect up to the Flight Controller using MK Tool? That would be where I would start -- both looking for high level errors in the main status indicators, and by scrolling through the so-called "LCD Display" in the center (above the four red arrows), and also specifically trying the Motor Test for that one "lazy" motor -- you can try and spin just that motor up using the Motor Test. See http://www.mikrokopter.de/ucwiki/en/MikroKopterTool Section 4. Hope that might help -- but let us know what you find. Andy.
No Errors what so ever anywhere. I did the motor test and at first it did work fine, but when i went back and started the motors through the remote it stopped working again. went back to motor test and now the same thing happens there. My feeling is that the BL is on the way out or it just went out. I still have the green all clear light on though. But i guess it doesn't mean anything.
Darren: The green light means that the firmware thinks it completed the self-test ok and does not see any errors. If there's no issues with the solder pads on the BL-Ctrl or the wiring, then as, you say, the evidence is telling us that (a) the BL-Ctrl has failed and (b) it has failed in such a way that the firmware is not seeing it. Just a thought: Are *all* the BL-Ctrls showing green LEDs illuminated. Not quite sure why I'm asking that, other than it's something I would check were I in your shop looking over your shoulder at your copter. Andy.
OK, i get what your saying. Yes all lights are green. Unfortunately besides doing some trouble shooting, im a little challenged when it comes to electronics, so off to Quadrocopter it goes tomorrow. Thank you for your help.
If you have time, please post again when you hear back from QC what they find was the issue. Thanks Andy.
Ive had this happen a few times back when I flew MK. Once it corrected itself after not flying for a week, strange but it never came back. The other time I replaced the BLCTRL and all worked as normal. It was also doing that occasional work normal, not at all thing.
Darren: You mentioned in your original posting that you'd tried your spare motor -- do you happen to know whether that spare motor is good? Gary's idea is a valid one, but if you tested with your known-good spare motor, it will be really interesting to know whether Gary's suggestion yields different results. Andy.