Patrick, the lack of failure data for the 4012 motors still makes me edgy about my setup. Does your retrofit work for your 4012 motors too? I'd hate to be the first guy to experience something like this.
Hey Steve, Yes, my apologies - this also applies to the KDE4012XF series. There have been no reports of any failures of this motor series, but we can still upgrade your motors to reinstall confidence.
This is what Patrick replied when I inquired about the changes " We have removed the chance of the failure-location that occurred (at the set-screw flat), changed to a much stronger shaft material (at a high cost for us), and changed the installation procedure. All of this is free of charge to the customer of course, so that we give you guys the best products on the market."
I would like to inform everybody about the progress: Patricks was so helpful with the support. I will be sending the motors to KDE for the upgrade which is free of charge. I'm also going to try the new 5215XF-435KV on MK Bl Ctrl 3.0 ESCs.
I can second that. I had twice a motor stop on me on two different flat Cinestar Octos with MK, and in both situations I felt nothing (besides doubled blood pressure and triple heart rate(;-) )
On this topic of motor stoping I also had a motor stop in flight and the Mk FC kept the craft level and kept its heading, where I was able to land safely, the only troubleshooting and attempt I could do to try to fix this on the field, was to disconnect and connect the motor wires and restart the motors, after several attempts all the motors started and I was able to finish the shot, the copter worked fine on other flights the rest of the day, my point is I did not do anything special other than disconnect and connect bullet connectors they all felt snug and well connected from the start, so why would this happened? how can we make a better and more solid connection between bullet connectors other than eliminate the blluets by direct soldering just yesterday on a different copter on start up, on the ground, 1 motor would not start correctly, it would spun slowly and jitter, same, after several disconnect, connect, attempts the motor eventually spin correctly like the others and I did flight with no more issues
Jose: The issue you're describing sounds like "decommutation" -- a problem where the brushless controller is sending three phase signals to the motor and the timing of the three phases is not quite right for the motor. I suspect that, while disconnecting and reconnecting the motor wires may have felt like you were doing something to correct the problem, that it may have not -- it can just be an electronic timing error. This concerns the "timing angle" being used by the brushless motor controller -- and that's a value that seems to have to be determined "experimentally" (and we are the lab mice!) rather than by looking it up in a table showing the various motor types. The bottom line seems to be that you cannot just select a particular motor and use it with a particular brushless controller without asking the question: "What should the timing angle be for this motor?" Unfortunately, all I know right now is the question. I don't know the answer -- or even the logic behind how to derive the answer other than "try this angle and see if it works and tweak the angle if it does not." Andy.
Thanks Andy that makes sense but the first time it happened in flight was MK Bl-2 with TM 2814 770Kv motors combo that has been proven to work together, the other copter with a A2, Maytech, and U5 that performs good (A2 wood knock knock) the night before I gave a close inspection to each of the male bullets looking for connectors that where not snug I found 2 or 3 that felt not snug so I slightly open with a xacto knife the split in male part. the other ones that some times loos the spring feature are the crown type I saw on Kopterworks that they use on some of the newer HL this type enclose in plastic connector
Jose: Yeah, a loose connector certainly can provide a very convincing simulation of decommutation! Andy.
In case anyone's interested in those Kopterworx connectors, they're at http://kopterworx.com/3-5mm-3-wire-bullet-connector-for-motor.html Andy.
Andy I think I going to give them a try or how about this perhaps this may fit inside the booms kind of like Flexacopter
The red trip The red triple connectors we use since years in the centre of the CS8 without issues. Makes dismantling quicker, easier and is safer as it is less likely for three to come apart than one.
Did anyone experiment with the flexacopter boom end connectors? The type that makes aligning motors/booms easy? They are expensive, however now that many are running X8 you only need four connectors. http://shop.flexacopter.com/25mm-tubeconnector-quad-set-p-268.html
I used Castle Creation bullet connectors and solder the connectors directly to the BL pads. Haven't had one issue since.
Thanks. Looks like you can get them here: http://www.helidirect.com/rjx-mt60-3-poles-connector-for-motor-p-36565.hdx and several other places. Andy.