Originally Posted by rangamatchstic
The Emax was very smooth, you could hear the gears but meh, also if i was running it on 6v maybe it was a little faster than 0.05 =P
Have you ever tested the speed with a servo tester?
I've tried three sorts of 9257 clones so far, from the thousands that are available. The first no-name eBay one obviously used a cored motor, since it was about 0.11s at 4.8v. The HK15158A gave 0.08s, so it must have a coreless motor. There was no difference that I could see in the circuit boards. I've had both of the servos burn out on my HK 450 Pro, which I attribute to running them at 6v. Even though the specs claim they can work at 6v, I would be a bit reluctant to try it unless the servo was sub-$10. I think the eMax has metal gears, so it might even be slower than the cheaper plastic gear ones, and to my mind, plastic gears are fine for tail servos on small helis.
In general, your mileage will vary with 9257 clones, but it seems to me that it's safest to run them at 4.8v. The HK one has horrible slop in the gears, but mainly caused by the second gear. When I replaced that with the same gear from my other dead 9257 clone, most of the slop was gone.
The next one I'm trying out is the Fitec FS9357D, plastic gear version. That's a fancy name for a 9257 knock-off, but 9357 has got to be better than 9257, right?