Chris you could pull the GPX file and see if you see any anomalies. Can't tell from the photos but do you have the Navi board installed on top of the FC board in the center stack? If so one of the reasons in the past for moving it out onto, typically, boom 1 was that there was to much EMI interference under the batteries from the battery wires. PH and Compass readings improved greatly by moving it out on the boom. If you are using an Graupner radio you should also take a look, pre takeoff, at the compass value. If it is lower than 90 on this display screen then it is a good indication that it won't be of much use. Information on this can be found at http://www.mikrokopter.de/ucwiki/en/MagnetError?highlight=(mag)|(compass)
tiger 3515 400kv is a very popular motor, I'm amazed that one burned with a 2nd motor nearly doing the same at that payload. The 3515s are said to run hot though. You may need to upgrade to the new MN series or the Avoroto 3520s 400kv.
Hey Howard, it would be just my luck to need to look at new motors, since I have 24 3515 here at the moment ... Thanks Gary, I checked the GPX files the mag field for all flights was greater than 100 in the GPX files .... the only magnetic errors occurred when the motor let the smoke out of the wires .... larger current flow when shorted maybe?? (GPX attached) The GPS and NC are mounted together out on Boom 1, just the FC on the centre hub.
Chris could it be that there's one or two bad ESC's or something that's causing the ESC's to send out higher current? Before you get too involved into looking at other motors could you switch ESC's in the locations where the bad ones started smoking and see if it follows to different motors. Since you have 24 of them maybe you can do a little experiment? Also looking at the picture I don't see the GPS and NC, is that a current picture or is Boom 1 blocked by the batteries?
Those burning motors are quite worrying. What was you AUW when the motor burned? I hope this is just related to these specific two motors. Just a note: (Tiger Motors had quite big problems with their quality check before. Their MT2814 series' bell was playing after a few flights. Most people were thinking it's a bearing issue but it turned out to be c-clip was not tighting the case enough. I had like 60 MT2814 and 20 of them had this issue ) BTW, I'm building a heavy lift MK setup with Herkules III V4 for 6S lipo. I will post the details once I finish the rig.
Not sure on that one Dave, the ESC's were the brand new FF set, The two motors definitely had a brown smell to them, all the motors were hot when I landed. It was motors 1 and 4 ...
Ozkan, the all up weight was 12.2kg ... a payload of 5kg, and two FF 6S 9000mah batteries onboard I have weighed the MōVI rig I intend to mount, and with the pocket camera and tokina 11-16 onboard that is 3.2kg, it still needs the teredek clip added and a random cable or two.
You have backup motors, so it would be wise to change only the motors and fly without plugging the movi on the copter with the same payload you did. AUW 12.2 kg is just very very normal for MT3515 motors. The ESCs can cause this also but you need to test them also. What I would do : * Wouldn't change the ESCs order and change the fault motors. * Add the same payload and hover just a minute. * Then land and check the motor temps immediately to see if the same motors getting hot or not.
Chris take a look at this post I made on the motor thread. I ran a bunch of motors through Ecalc for different prop sizes and AUW's. At an AUW of just 10K the 15" prop was way out of efficiency range. The 16" prop made it doable though. I kept the type of prop and all other variables consistent just to see what kind of effects weight and prop size had on a particular combo. Obviously you can get better results than the slo fly props I selected but I think it might be worth it to try a set of 16" props. Just wanted to show that to you. Take a look. http://forum.freeflysystems.com/ind...motors-4012-and-beyond.2749/page-4#post-33849
Thanks Dave, thats a pretty useful table, It makes the Mt3515s look like a poor choice as the weight goes up, so at my 12.2 kg, I may be over doing it on 15" props ... I have just powered up the second HL Build, and have come across what I would consider an unusually high min gas required. When I do the motor test on the second build the values range from 48-55 for the motors to spin up. I was momentarily concerned that there was a problem here, but went back to the manual for the I2C converter, and read the piece about calibrating the ESC's, and followed the process through. After this process motors all started up on a value of 15 again. What was interesting about this, is both I2C converters were bought at the same time from the same supplier, along with the FF PDB and ESC's, yet one needed to be calibrated, and one came calibrated (or so I think) A tip for young players I guess, or a random observation.
No problem Chris. Did you read about the I2C issues over on the motor thread. Apparently its been tested that you lose power through the converter and the best way to go is through the new MK BL's that will be coming out any day. That's what I am using for my heavy lifter.
Dave, After your ecalc post, I went there and punched in the values for the 12.2kg configuration on, and then just altered the cooling efficiency value in the top left corner, and it varied the results enormously, from a 38 degree with excellent cooling efficiency, unto 98 degree with a very poor efficiency, so now entering the realm of hypothesising .... potentially since I was just flying around in very cautious manner whilst doing the weight test, I may not have been moving enough air around to keep the motors cool ..... hmm ... as I type that it sounds stupid, as there is a dirty big prop over each motor ....
When I ordered the parts for the current two copters, the MK BLs were vapour ware .... but I have another frame lying around here, with 550mm booms, so maybe that should be built up with 16" props, and the MN 4012-9 .... however it appears that combination will need 50A from the BL or ESC ... any word on what the v3.0 BLs are rated to current wise?
It really does depend on your payload. It appears that the 3515's are really the ideal motor for GAW's around 9000 or below. Over 9kg I would really suggest looking at either the Tiger MN4012-9KV480 or the Avroto 3520's. I'm starting to think that the 4012's are really a good motor for different GAW's where you simply change the prop for different payloads.
I have not heard any specs but since the BL2.0's are rated to 40A I would think it would be a safe assumption that the 4012-9's would work with the BL3.0's.
What values for Max Gas do people generally use, the default of 230, is there a heavy lift preference that is better, there is not much detail here http://www.mikrokopter.de/ucwiki/en/MK-Parameter/Misc
Chris looks like you may be overweight. Running this through ecalc with 15x5 props it shows an 82% hover throttle. You may have also damaged other motors but they didn't smoke.
2.01g PH is significantly better. CH pitch is still quite abrupt, but I guess when you want her to come home, no need to dally... Joe