Hi Phillip, The MK telemetry will speak the errors when they occur and keep on looping. It sounds something like, "Warning, Motor Error" in a soothing female british voice which is somewhat alarming and soothing at the same time. The temp warning will happen over 100C, but the only time I have seen that with the BL3.0's is when the prop is on backwards and/or the motor is turning the wrong direction. What is the board version? It should be printed on the board. Best, Jeff
I definitely remember the voice saying motor error and other than reporting on the signal strength and the voltage error, she never mentioned anything about temp/heat. I am going off memory since the board is at the studio and I'm at home this morning, but I'm 99% sure it's says BL 3.0 on it. I remember searching for that specifically on this forum and on others to see if I could find any other similar failures when I first took everything apart and discovered what had happened.
Phillip. I've got a bit of experience with the whole bc ctrl issues... i ordered one back in april and it blew while on the bench... QC and the guys at MK shipped me a new one with some damp proofing and that one worked a charm. One thing I've learned... I bought a prebuilt rig 18 months ago or so. I've had a trial by fire in lots of fronts with it... I have a long history with electronics and RC back in the day, but I bought it RTF thinking it would be the best way to get me up and running, and now, after 2 full rebuilds of my own, I realize that in my opinion, RTF is awful. I'd never ever do it again. Even thou you think it'll save you, you never really know your rig till you've torn it apart and put it together. Now that I know every solder joint and every wire on the frame ... I'm confident that I have no cold joints. I know of one other person who over a year ago bought a CS 8 ready to fly (not sure where), and they were flying over some snow on a snowmobile shoot and the main connector from the lipos let go because it was a bad/cold joint. He was only 8 feet over a snow drift, but he was really shocked... cuz you can't see joints that were done by someone else inside a connector. I won't be able to add anything more technical than Steve or the other huge minds on this forum, but I will say from someone who started cold and worked through many technical issues, as you move forward - take the time to build it yourself and know every point, every wire, and every solder joint... not that it will prevent hw failure... but the questions will be fewer... and always have that sd card in when you fly. My heart goes out to you... I know how it feels. good luck getting it all pieced back together. steve
Thanks for the kind words, Steven. I agree with you 110% WRT the value of RTF builds. These things are truly in their infancy, and while I’m deeply grateful and fully supportive of Quadrocopter, I buy parts from them and build stuff myself. I have gotten great support in my efforts, and have learned more than I could have imagined. At the end of the day, I’m a card-carrying disciple of the church of “the devil you know versus the devil you don’t”.
I confess. When I first started with copters, I bought two CS8s. One RTF. One kit. Both from QC. I'm sure Karsten thought I was a bit weird. After I spent time with him (collecting the RTF), he knows for sure. I wanted to know how to maintain the RTF and the only way I could think of doing that was to figure out how to build one from a kit -- the RTF served as the model -- and I ended up with a primary aircraft and a backup and my brain was full. As Justin Marx observed (well, in the form of a question): There is no Easy button when it comes to the larger copters. Andy.
Thanks for the posts on RTF vs home built gentlemen. I do agree that building your own kit is the best way to learn the entirety of the system. This CS8 HL that we bought is just our first, my plan was to learn as much as I could about this platform with this basic CS HL and then build a custom X8 variant off the CS/MK platform that would better suits our lifting capacity needs(especially once we upgrade our Movi to a M15 which will add weight). We would keep this CS8 HL for flights with smaller cameras like a GH4 and extended flight times. I definitely didn't expect "plug and play" when I bought the RTF CS8 HL, but I also didn't expect to have to completely rebuild it because of no fault of my own. I will say though that the support on this forum has been awesome! I'm grateful to have a group of people that are so knowledgeable and willing to help. I just can't wait to get the cinestar back in air, it was such a blast to fly. As a DP, the possibilities that a Cinestar and a Movi open up are endless and extremely exciting just to think about!
I'm still waiting to hear back from Quadrocopter, called and then emailed on Thursday a very detailed description of everything that happened along with images of the damage per their request from our brief phone conversation. I was hoping to get something figured out with them early this week as I leave town for a series of international shoots starting tomorrow afternoon and going through July 3rd. I would love to be back in the air early July, but at this point I'm not sure that is going to be possible.
I am happy to report that the cinestar is back in my hands and flies beautifully! I ended up shipping it back to QC as I had a 3 week long shoot that I was out of the country for and thought they would do the repair while I was gone instead of it just sitting back at my studio. They were able to repair everything for me at a very reasonable cost and had it done when I returned from my shoot. After verifying everything was setup correctly in MK Tools I took it out last night and with the help of my wife, test flew it. The first flight was terrifying, not exactly sure what happened but after doing a full pre-flight check, calibrating the compass, calibrating the throttle, calibrating the gyro and arming the motors it immediately took flight(even though throttle was all the way down). It shot up hundreds of feet as I tried to gain control. I was not in GPS Hold, or altitude hold mode, supposedly fully manual. After a few seconds of panic, I flipped it to altitude hold mode which did nothing, and then flipped to GPS/Come home mode. It immediately stopped climbing and began to descend right to it's take off location. I let it land itself as I was scared to try and switch it out of CH mode. I then shut the motors off and grabbed my MK Tools computer. I checked everything, no errors, no problem, everything seemed ok. The throttle was correct in all the places I could check it. I then re-did the compass calibration, throttle calibration, and gyro calibration. This time I had my wife hold the copter above her head as I armed the motors, everything worked perfectly. All controls responded as they should. I did not change anything in the MK setup, I just re-did the compass calibration(though I was originally flying in manual the whole time, until I hit the CH switch). After passing the "tethered by the wife" test, I put it on the ground and gave it a whirl. It flew perfectly. No problems at all. It responded exactly how it should of and flew PERFECTLY. I flew it again this morning at a local park before anyone was there and it again flew perfectly. I'm excited to have it back in working order, definitely looking forward to getting more flight time and learning as much as I can about the MK system. Workstation at the office... From this morning's flight. The only problem I'm now having is concerning a new battery I received. When plugged into my i720 charger, it errors out saying it is only a 5Cell battery. Same goes when I plug it into my cheap old battery tester that plugs into the balance plug. The voltages don't seem off, it just doesn't show a 6th Cell. I'm guessing it's just a bad battery from the factory, but I thought I'd ask here incase there is something simple I can do to rule that in or out before I contact QC for a replacement. Thanks for everyone's input and help in this thread, this forum has some amazingly knowledgeable people and your willingness to share is unparalleled. Hopefully someday I can contribute as much as I've learned.
Philip: I'm concerned to read the story of your first test flight. Something was very, very wrong. Did you by chance get a GPX file on a microSD card that you can post? I don't want to worry you unnecessarily, but that first test flight was so aberrant that I would spend some time trying to understand what might have gone wrong. Could you amplify what you mean by "calibrating the throttle?" What stick movements did you do, please? Andy.
I echo Andy's concerns, and I would strongly recommend that if you EVER experience something even half as scary as that uncommanded ascent, that you DO NOT FLY again until you know what happened. Do you have a microSD card in the Navigation board? If you do, please share the GPX file from that aberrant flight. This kind of thing is extremely dangerous. If you don't know why it happened, how can you know it won't happen again?
just my two cents here... and it's worth exactly that... while i've had issues with MK stuff, nothing at all that scarey. It's odd that it seems to have corrected itself... but on that note, I went out on a shoot a few weeks back at 5 am to get a sunrise shot... and we calibrated the compass and did a test flight, and it was all fine, then the bird did what I can only call a fart. (pardon my crassness). It was like the MK system took some kind of hit and the compass wouldn't stay calibrated, but more oddly some of my flight/channel assignments changed themselves. Never seen it do that before... I had my laptop handy and went in and found it had disabled gps mode, and moved the altitude hold assigment to a different channel... so I reset it all and it worked great.... all I can say is welcome to thunderdome my friend... and be careful till you have the system working reliably.
Andy, Thanks for the reply. Something definitely went wrong with the first flight, I do have the GPX file, I've uploaded it here. Please let me know what you see and if anything stands out. I have also uploaded the GPX file to my latest flight from earlier today that went well for comparison. I noticed that there was error 32 on the problem flight and a problem with one of the motors(I think). I'm no MK expert, so any insight would be much appreciated! Flight with problem: 14071900.GPX Flight from today: 14071904.GPX Sorry for the incorrect statement, I actually did a accelerometer calibration (left stick up and to the right until the beeps). I did this with the craft level and pointed north(though the last part shouldn't matter).
Steven: That sounds like some kind of a noise spike had corrupted the MK Tools settings in flash memory. Did you report this to Holger at Mikrokopter. I suspect he would want to know about the der Furz (if you pardon my crassness ). I would worry about that kind of transient failure. T'be sure it could drive a man to the Guinness. Mind you, it takes very little to drive me to the Guinness. Even writing this posting and I can feel that I'm being driven.... Andy.
Hi Steve, I was very nervous to try again, and if I hadn't gone through the successful tethered test flight, and then reviewed the GPX files and noticed there were no errors, I would not of flown again. With the short, 2 minutes that I did the tethered test flight, the data all looked good, no errors and from what I could tell everything was correct. I compared the two GPX files in the field and noticed errors in the first flight that were not there in the tethered second flight, so I thought I would give it a go. It probably wasn't the wisest decision, but having all of the info I had I went for it and thankfully it worked out. The uncommanded ascent was one of the scariest things I've experienced, short of the crash that started this thread. If the CH switch didn't work, my next step I had already decided would be to kill the motors and hope the damage would be minimal. Thankfully it didn't come to that! I did have a microSD card in the navi board, and I've attached the file for you to check out. I've also attached the GPX file from the flight I did this morning that went as planned. Flight with problem: 14071900.GPX Flight from today: 14071904.GPX As I've mentioned a couple times, I'm pretty new to the MK system(lots of experience with other MR FCs though), so any information that can be learned from these GPX files would be greatly appreciated! I would love to get to the bottom of this and know exactly why this happened. The idea of it happening again is not something I want to risk, especially in the future when we're flying a camera under the rig.
Wow. I don't want to worry you, Phil, but something is badly wrong. In the first eight seconds the copter went from 1.749 meters elevation to 91.135 meters. The total current peaked at one second into the flight at 150 amps, 3.491 Kilowatts! The throttle was at about 60% in the first second of flight, then set back to 0% even though the aircraft continued to climb. Here is a graphic representation of the flight. At first blush this is completely internally contradictory -- you opened the throttle to take off, but the copter continued to do an emergency climb for the first eight seconds. The vertical scale is distorted by having to show 3.459 kilowatts of power -- the red blip is the throttle -- and the green is the altitude -- the green doesn't look like much, but the vertical velocity is 90 meters in six seconds...that's 33 mph straight up to 298 feet. From the outset, all of the data rows in the GPX files show an error 9, Motor Error. That normally occurs when a motor shuts down. If you don't mind, I'm going to email a link to this thread and your message above to Holger at Mikrokopter as I think he needs to know about this -- an uncommanded ascent suggests a serious safety issue. Andy.
I see something very interesting. I see that the compass is not calibrated (why were you able to start your motors without calibrating?) and you were in Altitude Hold from takeoff. And it's clear that the uncommanded ascent was due to the fact that the copter believed that its desired altitude was somewhere far higher than your takeoff spot. Curiously, as the copter was ascending like a bat out of hell, the variometer was indicating a descent. What this implies to me is that there may have been a serious error on the I2C bus, a software crash on the Flight Control Board, or a defect with the altitude sensor. Upon further reading, I think the problem was that you took off without calibrating the MK electronics. I don't understand why that would be possible unless you shut off all the failsafes for ignoring compass errors, etc. But even that...I don't know how this should be possible. I also see that you have an external compass. Is that true? Lastly, as a word for others, I strongly recommend never taking off with AH or PH engaged. I always take off in Manual mode, then engage those functions one at a time (if at all) once I've reached 10-20m.
Thank you for all the info, that definitely confirms what I saw on that flight. I've never seen the copter move that fast vertically, and that I did intact immediately killed the small amount of throttle input I was giving as soon as it took off. I usually "spin up" the motors just a little after starting them and before takeoff to make sure the throttle is responding it at it should, that bump in the throttle is what you mention in the first second. It seems to me the problem lies in the actual MK FC, since as soon as I flipped the CH switch, and the NAVI board took over, all was fine. Which is weird considering Steve mentioned seeing a compass error. Feel free to send this info to Holger, I'd definitely like to know this would never happen again, in any circumstance!
Steve, it's odd... I just completed a compass calibration prior to the flight. My wife and I wrestled the craft around and had a successful calibration (or so I thought). After doing the calibration, I plugged the copter into my computer and ran the MK software, it found no errors. Everything was green and it had no issues that I could find. No mention of a compass error, which I've experienced seeing in the MK software(and hearing through the Graupner telemetry). I went through every window to make sure everything looked good. I even opened the 3D windows and verified that the craft was reporting the correct tilt and such when I would physically move it. I then closed down the software, disconnected the USB, disconnected the battery, plugged the battery back in, let the GPS get a fix, calibrated the accelerometer, calibrated the gyros and armed the motors. With a slight bump in throttle, the craft jumped off the ground and just kept going. I was in Altitude hold as you mentioned for the takeoff, thank you for the info on leaving that off until airborne, I'll definitely keep to that from now on. I do have an external compass. I think you're right about the calibration causing the issue. However, I think it's because of a bad calibration, or one that maybe didn't write to the board correctly(is a corrupted calibration even possible?). I definitely did a compass calibration and acc calibration and verified that all was well through the MK software prior to takeoff. Thank you for taking the time to help figure out what happened!
Errr...I'm not sure that's quite right, Steve. Here are the first 21 rows of the data from 14071900.GPX: The Variometer is reading positive values for the first 16 rows -- which appears correct given the bat-out-of-hell uncommanded ascent. As I think you saw, there are no I2C bus errors shown in the GPX file. I didn't think you could disable the fundamental calibrations -- compass calibration, sure, but I didn't think you could even start the motors without the ACC or gyro calibration being done? Also, do you see any data suggesting that the MK boards had the throttle set high enough to cause the ascent? The GPS Sticks do not reflect the behavior of the copter. Motor #8 was in NOK (not ok) status and that's worrisome but, again, I cannot quite correlate that to the bat-out-of-hell take-off. I agree that AH enabled at take-off can create some "interesting" take-offs (some would argue they produce better than normal takeoffs given the way I fly). However, I'm not as concerned about a PH take-off given that you have >8 satellites and a solid 3D lock. Agreed, it's probably not the best thing to rely upon, but I've had to do it when taking off in narrow confines -- or landing on a one meter square Haynes-approved blue tarp in windy conditions. Holger requested I send him the GPX files so I'm waiting comments from him. Andy.
Philip: could you connect up to the MK boards using MK Tool and "Save" the settings to the a .mkp file and then post that file please? This will record the MK Tool parameter values. I just used my administrative power to permit you to upload files of type .mkp -- but if, for some reason, i messed up, change the file name by suffixing .txt to the end of the file name. Andy.