Brushless motor stuttering (sometimes..).

[AndrewNZ]

Greetings,
I'm having trouble with my electrical set-up in a new model. I have a new motor, a new 25A ESC, and a good receiver. On a test run everything will be ok but then, next time the throttle is opened the motor will be stuttering - not able to run smoothly. I stripped the whole system, checked every component including wiring continuity, re-installed everything, and all ran properly. But then on next startup - motor chattering again. It's only the throttle channel - the rudder and elevator are still working as intended.
Would appreciate any advice. Thanks.

 

[Konrad]

ESC settings are inappropriate for the impedance of the motor. What specifically is your set up

 

[AndrewNZ]

Hi Konrad, thanks for replying.
Set up is:
Battery: Turnigy 3S-1800mah Lipo, ESC: Turnigy Plush 25A, Receiver FRSKY V8R7, Motor RaceStar 2200KV (for 2S/3S)
In a powered glider 1.7m span, flying weight 900grams. Wing loading 7oz/sq.ft.
I have used exactly the same set up in an earlier model (another powered glider) which is still flying, no problems.
I'm still a beginner to RC and have just learned about the need to initialize the ESC, which I will do today and see if that checks the stuttering of the motor.
Andrew.

 

[Jarron]

Have you made sure your motor mounting screws aren't too long? If they contact the windings inside the motor, it will cause this if not destroy the motor.

 

[Konrad]

Unfortunately you haven’t told us your current draw (Prop size would give us a rough idea).
Also the products you do list, other than the receiver, are generally of low quality. That is they have wide tolerance bands. That is sometimes they work well together other times they don’t.

I don’t know if your ESC is compatible with this programing card. You are looking to be able to change at the minimum the timing and frequency of the esc to try to match the motor.

Turnigy Plush-32 Series ESC Programming Card

The Turnigy Plush-32 series of ESC gives a fast response to your every input comes. Get this programming card to make life easier programming the Plush-32 ESC.

hobbyking.com

 

[AndrewNZ]

Have you made sure your motor mounting screws aren't too long? If they contact the windings inside the motor, it will cause this if not destroy the motor.

Hi Jarron, no, the mountings have all been checked and all are ok.
I've just 'initialised' the ESC - looks like that might have fixed it. Will need a few more test runs to confirm...

 

[Flying Dutchman]

I've had similar problems with a Plush-32 series ESC. The programming card is actually required (not just 'nice to have') to adjust the timing, very annoying. Rather than spending more money on a single use accessory, I decided to chuck it and use another ESC.

 

[Konrad]

I've had similar problems with a Plush-32 series ESC. The programming card is actually required (not just 'nice to have') to adjust the timing, very annoying. Rather than spending more money on a single use accessory, I decided to chuck it and use another ESC.

That’s one solution. But for $5 I’m happy to pay that for ESC programing cards. It is so much more convenient than counting beeps and stick positions used on most other entry level ESC.

I probably have 90% of the ESCs covered with the cards I keep in my flight box. This often makes me the hero for a day!

Now the web based ESC are great!

 

[AndrewNZ]

Unfortunately you haven’t told us your current draw (Prop size would give us a rough idea).
Also the products you do list, other than the receiver, are generally of low quality. That is they have wide tolerance bands. That is sometimes they work well together other times they don’t.

I don’t know if your ESC is compatible with this programing card. You are looking to be able to change at the minimum the timing and frequency of the esc to try to match the motor.

Turnigy Plush-32 Series ESC Programming Card

The Turnigy Plush-32 series of ESC gives a fast response to your every input comes. Get this programming card to make life easier programming the Plush-32 ESC.

hobbyking.com

Not a lot I can do about the components at the present time, but I have just done an 'initialization' of the Plush ESC, and at this point the system is all working. Will do a series of test runs over a couple of days to confirm everything's still functioning as it should. Thanks for the hint re the programming card. I will get one as I think I have four or five Plush ESC's of different ratings, and not yet used.
Thanks for your help.

 

[AndrewNZ]

I've had similar problems with a Plush-32 series ESC. The programming card is actually required (not just 'nice to have') to adjust the timing, very annoying. Rather than spending more money on a single use accessory, I decided to chuck it and use another ESC.

Thanks for your reply. I will get a programming card - it might save me having to ditch another four or five ESC's - as yet unused.

 

[Flying Dutchman]

Yes, makes sense if you have a couple of them. But be careful with the versions. I assume the latest card version is backward compatible to older ESC's. The HK descriptions are not always clear.

 

[Wayne]

Glad you got her working. This little issues slow us down a bit, always worth it in the end when you get to fly it!

 

[DaviBrons]

It is very easy to overheat a small motor on a large model with the wrong gear ratio.
Turn the shaft, the rotor with a working magnet should resist, as if flipping from one position to another. It is easier to compare with a similar serviceable one.
The resistance force depends on the type of magnetic system (there are also smoothly rotating types) and the "strength" of the rotor magnet. If the rotor is overheated, the magnetic properties deteriorate, the torque and power drop. Try to hold the shaft a little with your fingers and a little on the gas - if the magnetic properties are lost, the moment begins to suffice only to spin the engine without load.
Serious manufacturers sell rotors separately, both for modification and for such cases.
Well, or you can do something more radical. I would start by replacing the ESC.