Jlerch
Senior Heliman
Location: Parrish, Florida
| First, here is an HD video I shot of me testing a JR DS890G tail servo that gave me a few too many mg of Adrenaline today during a "Landing"
http://vimeo.com/1669148?pg=embed&sec=1669148&hd=1
Other than mis-speaking a few times, is this a sound test to verify that the servo is indeed faulty?
I've been noticing over the last few flights, that I've had to dial nearly 10 points off the gyro gain to keep the tail from oscillating. At the time, I blamed my flying style, assuming that it had changed. My justification for the gyro gain change was I was getting oscillations from flying faster than normal...
In hind site, the servo was failing, getting weaker and slower during each flight. Slower servo takes a lower gain to keep from oscillating (right?)
On the assumption that I didn't screw this up (possible) perhaps its time for a new "Pro-tip: If everything has been flying fine, and suddenly you have to start lowering your gyro gain to keep the tail from oscillating, perhaps its time to land and do a finger test on your tail servo."
BTW, this is how I found mine. After a hair raising attempt to get the wildly swinging tail under control, that continued to go both ways even after hitting throttle hold, I was inspecting the tail for damage after the "Landing" I thought something mechanical came loose, so I tried twisting a tail blade to find the loose ball joint. To my surprise the tail simply twisted in my hand with only modest resistance, and all the ball joints and linkage was fine. This would have been a serious PITA to catch on a pre-flight. I would actually have to perform a torque test on each servo prio to flight... (Yuk)
So, I this a valid test for this servo? Did it fail?
(Still new to RC testing methodologies, but I vote this servo failes!)
/more info in the video captions on Vimeo (just click on the video to goto the site and watch in HD )
James Lerch - ManateeRC Member - Blade 400 - Raptor 60 - Lots of sim time |
