Mikrokopter Phase B error

[Droider]

So I am almost there .. I had tested everything out and run a motor test an BL temp test on my new test rig.... so I go back half hour later and I am getting a two blink red on my BL 6.. the one I swapped out this morning because of the stuttering motor..

Now does the blink say its the BL that has a fault on phase B or is the fault in the motors Phase B?

DAve

 

[Bartman]

dave,
i suppose if you pull the bell off the motor you can test for continuity and maybe detect a short with a multimeter. as for the motor phase someone said somewhere that you can try to map the motor signals with a scope to see what is being sent from the ESC's but that's well above my paygrade.
Is it an old motor or a new one? You fancy the nice motors, don't you!
Bart

 

[Droider]

Think its the motor . Just soldered a replacement motor on the BL and no error.. Just another lesson eh!?

Guess when you have a major incident you should just bite the bullet and do it all.. rather than trying to bandaid stuff..

Dave

 

[pootman]

Hi Dave,

My BL3 had three red blink on the led after I thought I had everything straightened out. When I looked it up on the wiki it said it was a Phase C error. I noticed a tiny amount of solder that had apparently dripped on the BL durning soldering. I'm assuming I fried the BL and never thought about checking the motor (brand new motor).

Lance

 

[Droider]

Check the motor.. if its the BL the motor stutters

Dave

 

[Droider]

Update..

Well I changed the motor and still the Phase two error.. so this is what I did.

de-slodered the motor.. powered up the copter and no problem. No Phase error. So with the board powered up I soldered the motor up and bingo.. motor tests ok everything as it should be. So I power down the copter and power it up.. If I get the Phase error again I can desolder, power up and re-solder and everything is ok.. OR

I get no error but the motor stutters with no error reported... GRRR..

I thought it may be something to do with the phase changes I did in the BL set up.. So if the error is phase B and it is active the BL set up pain says incompatible software. BUT if I unsolder the motor, power up and have no error on the BL I can change the settings in the BL pain...

I will swap out the BL for a brand new one but its really getting at me that I cannot find answers. I dont expect answers on this forum to such technical and individual problems but I would have thought on the MK site I would have found my answers... but it would appear that even though my posts get hundreds of hits no one really has the answers..

Double Grrr.

Dave

 

[Bartman]

dave,answers or not, with the heat you're getting in the one BL it should just be swapped out and left for another day to figure out what happened to it. summer's almost over.
bart

 

[Droider]

I know summers almost over and I have missed the best bits... grrr!

 

[Crash]

Different threads for the same problem make it very hard to keep track of things. Which BL-Ctrl do you have? V1.2 and V2 are very different.

The MK Bl-Ctrls are a bit of a mystery to me. I only know of two people that may have a clue about the technical aspect and they only post on RCG as far as I know. You will probably find the best answer on the .de site to a more technical problem.

One problem people run into is that a bad motor can fry an ESC phase, and a bad ESC phase can fry a motor. It would not be a bad idea for you to get a couple cheap stock ESCs and motors to do testing. I also made a post here with motor testing links.

I have noticed that a bare motor can spin up properly with only two phases firing. If you put the weight of a prop on it then you can see the stuttering and the bad phase.

I do not think that the MK BL-Ctrl error feedback extends to or past the FETs. IOW, I don't think it can tell you if a motor winding or FET is bad. I could however be very wrong on this. Someone please correct me if I am.

In any case, if just one FET got too hot to touch as in your other video, something is very wrong. It is sucking down way to much power and a regulated power supply with an AMP meter would have told you that - maybe even before real damage happened.

 

[Droider]

Hi Crash.. Thanks for your words of wisdom.. The multiple posts are stupid but I could not get answers from the .de site so I thought I would try rephrasing the question!

Could you post a link to the best place to post a structured thread on the RCG forum

Thanks

Dave

PS have NEW motor and NEW BL to fit tonight!

 

[Crash]

This was the thread I was referring to: http://www.rcgroups.com/forums/showthread.php?t=1336561&page=137
It's a huge thread so things get overlooked quickly.

I'll bet that the answer is going to be to change the BL-Ctrl which you are going to do anyway. I would pull it, put it in a bag labeled bad Phase B and maybe look into replacing the FET(s) and maybe a switching transistor or other SMD part at some point in the future.

Below is the schematic for the positive side of phase B. Look at those parts carefully and from an angle with good magnification.

Also below is a photo of a part from a brand new BL-CTRL with a similar problem to yours. In his case, he was able to fly until the motor smoked as well as a FET. After I changed the FET, I accidentally noticed this resistor.

I still don't know if that caused the problems or if high heat on an inner copper layer allowed the resistor to pull away.

 

[Droider]

Update.. changed the BL and the motor.. SHE FLIES!

Ill go check out that forum coz I do have a couple of weird ones like flashing red and green FC status light in MKtools with a new distribution board connected that has a 12c error!

Thanks crash..

Question; I have a brand new BL i soldered the caps on and then when I was fitting it a little brass coloured bit fell off.. I think it was next to 181, are these just links or is there some thing else to them. Wondered if blobed solder across the bits would make the bridge.. Maybe I should just send it back cause it does look like a cold joint. (bought a Jewellers eyeglass.. Perfect for close inspections)

Dave

 

[Crash]

Do you have a picture. I'd send it back though. Parts should fall off. EDITARTS SHOULD NOT FALL OFF.

 

[Droider]

Do you have a picture. I'd send it back though. Parts should fall off.

Check this out

 

[Crash]

I think I see an SMD parts missing but the pic is too small.

 

[Droider]

The bit that fell off is in the tweezers. It came off the pads just in front of the tweezers tips

 

[Crash]

Ah I can see it now. Maybe if you take a smaller picture I can use my microscope.

How did you get all of the solder out of the through holes for the caps?

 

[Droider]

I had not soldered the caps in at that point. Just tinned the legs and glued um on.

DAve

 

[Crash]

You don't need to tin the cap legs. I paste flux them before I solder and then clean off any gooey mess later. Wires are different though. They should be pre-tinned, especially the high strand count wires that most use.

Can you please take a mega pixel photo of the location where that cap fell off? I'm curious as to what the board looks like. Just do a screen capture or crop of that one part like I uploaded in post #11.