Problems with MGM 25035

[dropps]

Hello
My name is Jens Gabel and I live in Germany. I have a Mystic running with Neu 1521. Great boat. The setup is : 1521/1,5D (1900 kv) 6s Lipos and the MGM 25035 esc. But I got the problem that you controllers will not work probably with the motors. It seems that the ESC loses commutation at ¾ throttles. I hear a screaming sound and the motors looses power immediately
I tried nearly ever Setup in the ESC, but nothing worked. Can anyone tell me what to do? Or did anyone have any similar problem?
I appreciate your answer.
Best regards: JensDSC01134.jpgDSC01130.jpgDSC01129.jpg

[Fluid]

This used to be a problem with the low D wind Neu motors and earlier Schulze controllers. I never tried my MGMs with my 1D Neus so I can't say if it is common or not. It is a software issue in the controller, the D motors have such low inductance that the ESC loses the rotor position. Set the PWM and timing as low as possible, and try the motors on 4S. You may have to contact MGM for a solution.



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[RaceMechaniX]

Jens,

I have run the 28026 with a 1521 1.5D on 4S with no problems. Set the frequency to Auto and try the timing at 0. If no luck, try increasing the timing to 2 Deg and 4 Deg with any improvement. I would not go higher than 10 Deg.

I have run a 25063 up to 82k RPM with a 4 pole motor like the Neu's so it should not be a problem of RPM with a 4 pole motor.

Have you looked at the data?

TG

[dropps]

Hey guys.
Thanks for your help. I appreciate that.
This setup (1521 1,5D on 6s with x447) was installed in one of my earlier mystic. But not with the mgm esc. In that boat I used some CC 240 Hydra. And the Setup was perfect. That´s why I decided to install the same setup in this mystic.
Anyway, I tried a lot of different settings. I started with 0° timing, to 5, 10 and even 15°. I tried different PWM Setting with 2 kHz, 12 kHz and many more. Nothing worked. Attached you will find o YouTube link where you can see what I mean.
Running the Motor with 4s is not really an option. That would be something about 28000 rmp.....not much enough. I need something between 38000 and 42000 rpm.

I hope that anyone has any Idea......I´m more than disappointed. Spent so many bucks and time in the boot and it is not running.....

http://www.youtube.com/watch?v=rMUclhEqAM4&list=UUexH5tPdxF2TvbNplreDD4g

[oscarel]

Have you contacted MGM?

[dropps]

Sure I did.
But until now I got no answer. Still waiting.

[engineer_78]

Yes interesting! I was planning to motors NEU 1521 1,5D to use the regulators MGM, will be to keep track of how you will be able to configure the controllers!

[RaceMechaniX]

Jens,

It sure acts like you are hitting the current limit in the controllers. Have you looked at the data? There is an overcurrent variable you can select which will show when the ESC is clipping the current.

TG

[Fluid]

It also looks just like my Schulzes losing sync with the Neu D motors. That was with 1D motors though....




.

[MarkF]

We use to fix are schulzes by adding more capacitors before Schulze fixed the sofware. Steve Neu once told me that capacitors helped with low inductence motors and turning the PWM rate up sometimes helps too. I would make a bank of at least 5 caps and give that a try.

Mark

[oscarel]

Sounds like both controllers doing it together, how do you have power going to receiver? Can you post a picture of graph from one of the controllers?

[dropps]

Hello Guys.
I got some news for you. In the past it ought, that both esc have this kind of problem, but actually I would say that only one ESC has this problem. Attached you will find a detailed look at the logger files where you can see what I mean.
The first picture shows the rpm of the left motor. I was running for quite a while, until I tried to give full throttle. At 4:50 (moment of full throttle) you can see, that there is a huge jump in RPM. There you can see that you max. Rpm limit is reached and there for the esc reduces power. The log tells me that too. But if you look at the rpm of the left motor at the same time, you will see nothing like that.
This is why I think that only one ESC has the problem. And now I tell you why I think (but I´m not 100% sure) that the Motor is the problem and not the ESC.
As you know I have some brand new 1521/1,5 D Neu installed. What I found out, was that the two motors don´t have the same Cogging. (In other words, the permanent magnet detent toque between the rotor magnets and the stator pole shoes) I had this effect on my other Neu too, but I never had any problems with these motors. I used some CC 240 Hydra and they worked fine, until now (4 years). But the mgm seems to have a problem with the motor which has the low Cogging.
I tried every setup in the esc, but nothing worked. I´m still waiting for the answer from MGM. But right now, I have decided to put some other Motors in. I hope to get the stuff this week so that I can make a test ride on the next weekend. I´ll keep you informed.
Thanks for your help.
Best Regards: Jens
Motor Left.jpg

[RaceMechaniX]

Jens,

Can you confirm that both motors are from a similar batch (manufacturer date, similar motor windings, similar rotor construction)? Neu has gone through several different small variation in construction carbon vs Kevlar filament winding, skewed stator vs straight stator teeth, good insulation and magnet wire vs lower cost supplier.

The high cogging torque motor likely has a non-skewed stator with good magnet wire. This results in a "cleaner" back EMF profile which the ESC can read easier. With skewed stators, poor magnet wire or lesser grade magnets this degrades the BEMF making if more difficult to read.

I would check the motors for differences and next switch the esc's to make sure it's a single motor issue.

TG

[BILL OXIDEAN]

Hello
My name is Jens Gabel and I live in Germany. I have a Mystic running with Neu 1521. Great boat. The setup is : 1521/1,5D (1900 kv) 6s Lipos and the MGM 25035 esc. But I got the problem that you controllers will not work probably with the motors. It seems that the ESC loses commutation at ¾ throttles. I hear a screaming sound and the motors looses power immediately
I tried nearly ever Setup in the ESC, but nothing worked. Can anyone tell me what to do? Or did anyone have any similar problem?
I appreciate your answer.
Best regards: Jens[ATTACH=CONFIG]112910[/ATTACH][ATTACH=CONFIG]112912[/ATTACH][ATTACH=CONFIG]112911[/ATTACH]

REALLY nice rigging on this boat!
Good job : )

[dropps]

REALLY nice rigging on this boat!
Good job : )

@ BILL OXIDEAN
I appreciate you post. Thanks.

@ Tyler Garrard
The motors are both ordered in November 2013 and were built in December 2013. The look the same, they have the same weight, the same screws.....everything is the same. Accept the cogging. But this is something I didn´t feel worried about it because I had this effect on my other neu 1521/1,5D too. But as I told you, the cc 240 had no problem with that. At that time I started a discussion in a German forum concerning that problem, but nobody could help me.
Right now I will change the Motors. I ordered some 2240 LMT. We have a powerboat meeting in a couple of days here in Germany and I don’t want to spend too much time in troubleshooting. I need that boat running. But I´m still in contact with MGM and I hope to fix the Problem. I´ll let you know.
Best regards: Jens