Being careful which Electronic Speed Controller (ESC) to use

[Peter Hollands]

Folks

I decided to upgrade the brushless motor and ESC on my alpha axion 139. But I found that the new ESC had some problems.

I initially bought a 30A ESC from 4-Max Purple Power
and this motor with a 220W power.

I fitted this, with an upraded 3S battery to my spare Alpha Axion, but soon noticed a problem.

The ESC has a safety feature that means that if the prop ever stops spinning with the throttle up, then it shuts down the ESC.
If I slowly went from no throttle on the transmiter and increased the throttle slowly, sometime the prop would start, then stop on it's own. This was true only at low revs.
(it was in tickover), and then the ESC would shut down. I was worried that the autopilot might do this during autonomous flight,
but not know to reset the ESC by going to minimum throttle and then moving back up to a significant amount of throttle.

Also the increase in performance of my plane was disappointing. I tried the ESC on both high and low frequency settings.

So I dug out a spare Castle Creations 36A Thunderbird ESC. (click their Tab on their website for the 36).  I rewired that into the same plane with the same prop (6x4 pusher).
Immediately the starting thrust of the going from no throtlle and a static prop to slightly incrased throttle at tick-over and a moving prop, was much much better.
There was no problem with any safety features.

And when I flew the plane, it was transformed. The climb rate was what I hoped for.

So the moral of the story seems to be, people should be careful about the make of ESC that they fit to their planes. They have vastly different characteristics, and some are just not suitable for use with an autopilot. Interested in any comments and experience on this topic ...

Best wishes, Pete

[markw]

Hi Pete,

Could the problem ESC be defective? Perhaps a bad or weak output phase is the problem.

regards,

--Mark