Rating:
Application(s): Powered aircraft, gliders, NOT helis.
Comments: I run it from a 5v bec, a 4 or 5 cell nicad pack, or a 2 cell LiFe (6+ volts).
So far, the only problem has been that the output bearing seems to be of low quality, as they develop some slop fairly quickly. A friend of mine prefers the 928, which is an analog, plastic gear servo with, I believe, a bushing instead of a bearing. His comment was that the digital bearing servos got sloppy fairly quickly.
The bearing is a 5x8x2. I've been able to find a 5x8x2.5 from RcBearings, but not a 5x8x2, but I have not really tried to locate the correct size at this time. I may just try a 5x8x2.5 and see if it works.
Aside from the radial play in the shaft, they seem robust. There's some backlash, but nothing unusual for a metal gear servo.
Despite some other reports, I've had no problems running them on 6v, including using a 2 cell LiFe. I'm using them for the ailerons in my Acromaster, and their holding up well. Better than the HS55's the previous owner had used.