HXT-900 questions on an AXN Floater-Jet

Hey, guys. I've got an AXN Floater-Jet I'm using HXT-900s on with a FlySky CT6B transmitter. I'm using the exceed-rc T6config software to make adjustments to my transmitter settings. I have had 3 HXT-900 Servos start acting weird on me over the past 3 weeks. The servos will suddenly have almost 180degrees of travel, and they will not return back to their center position once I let off of the controls. If I adjust the centering on my TX, the servo will continuously rotate until it reaches the 180 degree mark or hits the bulkhead in the wall of the AXN. This started with my elevator, so I changed out the servo. No issues until I went out to fly today and the rudder and elevator servos are both acting up on me. I'm not sure if its a hardware or software issue at this point. I'm trying to experiment to eliminate variables, but I would also appreciate any wisdom from the community of more experienced folks. Any ideas on how to make sure the servos return to their resting position and have a normal degree of travel? Thanks in advance!

Ok, Fred. I will look into that tonight after work. I'm using the stock prop-saver with o-rings i picked up from Lowe's. They are a little thicker than the bands from AXN. I read a few posts where that was blamed for causing prop vibrations. At the moment, I feel vibration from the prop isn't as big as a contributing factor as crash landings. I've put this thing though some abuse, unfortunately. I'm obvoiusly a newb and got this plane for me to learn on. The last flight/crash (along with some fine views of the appalachians) before this issue arose with both servos is avaiable on youtube. ( http://www.youtube.com/watch?v=YE8hlfNUYBk ) If you think that impact was significant enough to cause the issue, let me know. I will get back with you on the diagnosis on the servos as soon as I am able to crack the hood on them. Thanks for your help!

Vibration will weaken the wiring (especially in very thin stranded ones) and the effect is cumulative (ie, it gradually gets worse until there's a final stress fracture).

It's possible that the wires were sufficiently wekaned from the vibrations before the crash and the final thump and sudden stop at the end could have been enough to make the last remaining strand(s) part company.

Also a sudden jolt could have ben enough to put a hairline fracture in the pcb (which would give the same effect)

Originally posted by appala If I had to guess, the 1 servo has about 2.5hrs on it and the other has about 30-45min of use. I'm surprised they have both failed in such close sequence. Any tips on how to tell if my prop is causing excessive vibration?

I'm surprised too. We probably have 50-60 of these, some in helicopters, and have never seen this kind of failure.
Easiest way is to balance the prop. If you don't have a balancer, try putting some Scotch tape at the back of one blade and see if it improves or gets worse. If worse, move it to the other blade and keep adding smaller pieces until it seems OK. Replace all the pieces with one or more larger ones if it gets messy. A prop(per) balancer is a good investment, though. Some of these cheap props are way out of balance, bad centering etc.

Fred

Sounds like I know what I will be looking at tonight after work! Thanks again. I'll let you know what I find. I really want to figure out why I've had three servo failures in the same number of weeks with such low hours.