Motor is hanging

[Kalle]

Thank u for the advice @Kinderkram
Iam little bit confused the ESC are "just" costing 72€ and not 90€ or iam i wrong?
Where would u sell the ESC? Do you think in the FPV Forum i would finde someone? I mean like we realized now they are not really made for multicopters...dont wanna "trick" someoneby giving him hope he made a good deal

Marco

[kinderkram]

The price is almost the same in various shops - you can also get them from Foxtech, Goodluckbuy and the like for ~85-90€
The price displayed at Kopterworx is without tax, with tax it`s 89€ a piece.

You might want to look at this thread:
http://fpvlab.com/forums/showthread.php ... EXPERIENCE

Someone showed off a comparison of the said T-Motors and the Turnigy K-Force 70A HV. Result: the T-Motors also stalled!


If you read a bit further, one expert (FerdinandK) demonstrated the Turnigys with good results - they are his actual recommandation.
They come at 55€ and seem to do the trick:
http://www.hobbyking.com/hobbyking/stor ... s_ESC.html

Oh ... and no need do trick anybody when offering the YEPs. They are good for helis or other motors so someone might be interested at FPVC or Ebay...

[JussiH]

Marco.

The data that Christof posted very clearly suggests that 12S with your 25" props is way too much and that efficiency will be very poor. Is there some special reason that it must be 12S?

In fact the data that christof posted, shows that a 26*8.5 will top out at 2365 RPM. Divide that with the Motor KV and you get a good idea of how much voltage is needed to reach full speed-.

2365/135 = 17.52 Volts

Your prop is gonna be a little faster so lets assume a top speed of 2600 RPM and the max motor voltage becomes:

2600/135 = 19,25 Volts

Clearly indicates that 6S would be sufficient and probably most effective, provided you could find one that could deliver the needed current without dropping the voltage too much....

So you might be better off to redo the math and choose a more suited battery configuration than to buy 8 new ESC´s and still have the same problem.

If you are stuck with some big 12S pack, you could maybe get it rebuilt to a 6s2p configuration and be better off with that. Also means that upcoming UltraESC V2, KISS 30A and ESC32v3 will be attainable (and affordable) options for this machine.

If you tell us what your goal is with this copter and give us more details about it, we could probably help u better.

[Kalle]

@JussiH
Thank u very much for ur long post! I am happy that the people here are explaining everything that even me iam understanding^^
Yes ure right the efficiency is not that good but i was testing this combination with 12 and 10 S at home and for flying around on middle throttle i have a higher flytime with the 12s than with the 10 S.
Maybe youre right with the 6S combination...iam sure the efficience is much better but i need to carry a bit.
All in all the weigth will be something like 14 kg of the copter and i thought a X Octo would be the best version...now that i was getting much more experience i would change a lot but the frame is already made and the motors bought like the props^^iam planing now since more than one year on that project and in the FPV Forum all people were really friendly and helped me a lot but with my experience in that times i couldnt really expact that they are "making" the copter for me.
I started first with a smaler copter and it was going so easy and so well directly that i thought i can handle a bigger project too...maybe i took little bit to much on my shoulders
First thing i will change on the copter is the distance between the two motors over each other iam sure that this distance is the key for a better efficence....maybe someone already made tests about that? I was searching in the FPV Forum and there are many threads about that but the results are not the really the same.
Not sure if its ok to ask that stuff in this thread...i think the problem of this tread is solved
Anyway thank u very much for the help would love to hear a answere on my last questions

Edit: I dont really need to fly full throttle the whole time and i need high thrust with the half throttle i can fly like i want. If iam flying with my combination longer than 20 min on full thrust the motors are going to hot. But i want the option to go higher with the thrust even its just for a short time.

Marco

[Kalle]

Hey together,
I made the new esc on (quadro) and everything looks perfect at the beginning...than on motor starts little bit smoking. I stoped and was checking the esc and the motor everythibg looks fine but on the smoking motor is on one of the wires inside the motor a dirty sticky spott....any idea what the problem could be? Same effect without props btw. The motor is still working but the smoke is scaring me
Marco

Edit: could it be a production mistake? That the isolation of the copperwires is just not perfect?
how would u program the esc?
I have:
Brake: off
Battery Type: lipo
Cutoff mode: soft cut
Cut off threshold: middle
Start mode: normal
Timing: 15°
Governor Mode: off
Pwm Frequenz : 12khz
Build in Bec Output: 5,25
Lipo Cells : auto

Edit: I made all props away and learning the ESC again. From 0-30% throttle the motor is "scratching" and when aim trying to go on 100% the motor is hanging very strong....
Pleas help me...

Edit:http://fpvlab.com/forums/showthread.php?31275-T-MOTOR-U8-and-ESC-compatibility-issues-ANY-EXPERIENCE
if i was understanding this post right means that right now there is no ESC for the U8 when iam using 12S... ?