[Oscy]

I'm putting a Hobby King 5045/500 brushless motor in a 60 size Escapade 60 with a Turnigy Plush 60A UBEC.

I'm using a 15/6 propeller for testing, and a 6 cell lipo battery

When I bring the throttle up slowly, the motor starts smoothly and gets up to about half speed, about 4000 RPM. As the throttle is pushed above half way the motor stops and a loud "shrieking" sound is heard. If I back off the throttle to zero and run it up again, the motor again works ok until I get to half throttle.

The motore is rated for up to 7 cells by Hobby King and the UBEC has a rating of 80 amps surge and 60 continuous. With the 15/6 prop I shouldnt be close to these limits.

Any Ideas What is causing the motor to stop and "Shriek" At higher throttle settings

Thanks for any ideas.

[JohnR]

I would send the motor back. But you should get a watt meter and see what it is really pulling. That way you could see what the levels are when you go past half throttle. There is a chance that the ESC or transmitter is programed wrong, but that is not likely. Send the motor back.

[fhhuber]

The symptoms match improper timing and/or excess prop load.

Poor timing setting will let the motor run until its in its power range then normal load will cause the screeching and it will stop.
this is more likely than just excess prop load.

You can also get this when one of the ESC output MOSFETs fails.

Its far more likely to be an ESC issue than a motor issue.

[JohnR]

That could be the cause also, but we just had two different motors from different manufactures that had bad bearings in them. This produced a very similar problem. You could change the setting in the ESC or try another one, if the problem is still there then send in the motor. Personally, I have never had an ESC that had the timing that far off to cause problems such as this. That is not to say, that it wouldn't happen. I would try out Fhhuber recommendations first, then move on to the motor. It could save you some time. :-)

[Oscy]

I tried reprogramming the ESC to High timing...Still Squeels..

I'll try another ESC and then try a new motor..This motor is rated for almost 2 horsepower...the prop is only a 15/6......I may try a smaller prop, but the plane will weigh about 9 pounds .....

Thanks to all for the tips