Three FM-9 users, one in California, one in Australia, and one in Germany have reported on a very strange and disturbing problem with one Castle Creations Edge Lite 50 ESC. Each has had one that worked properly and one that did not.
The symptom is that, after the motor blip, there is a screeching sound as the timing of the PWM pulses to the motor aren't properly synchronized. Sometimes the motor greatly over revs. Usually it settles down, finally, at the programmed RPM.
The Australian user send me the problem ESC and I was able to reproduce the problem on my test stand. Extremely unnerving and unpleasant!
I sent an email to Castle's user support email address and received a reply from Clint Akins, Outside Sales and Support. Even though he was on the way to the Joe Nall Fly-In, we arranged to discuss the problem over the phone. I hooked up Castle Link and we went through the settings. Without changing them, he had me use the "Update" button to send the same settings to the ESC. To my amazement, that cured the ESC, as I verified with a bunch of different programmed RPMs.
Clint says that he first heard of a similar problem at a helicopter meet and this is where he found how to correct the problem. He feels that the answer is that the ESC sometimes reads the information from Castle Link incorrectly (even though it implements an error-detection scheme, but presumably one that doesn't catch all bit errors). (I have never heard of the problem occurring on the Phoenix or the ICE or the Talon.)
I'm impressed that Clint took the time to help address this problem in a timely fashion.
I would appreciate it if anyone else who has experienced this problem and who tries, hopefully successfully, to cure it will comment on it here.