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Questions on Broken Servos - UMX Radian

#1
So my umx radian just ate some turf (attempted inverted flight may or may not have been responsible for said turf-eating, but regardless...) and the only thing that seems to not be working after a full throttle nosedive is the servos on the motherboard. No input from the controller will move them and the AS3X is also not affecting control surfaces at all. Binding and throttle still work perfectly, and there doesn't seem to be any other physical damage. My questions are:

1) What could be the problem here?
2) has anyone else had this problem before?
3) is there a fix besides "get a new $65-75 motherboard for your $80 airplane"?

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#3
Did you try and rotate the gears on the servos to see if they are bound up may just be jammed.
Yes I did, and they were moving no problem with manual rotation. Also if they had been jammed then the mothers probably would have strained a little or moved slightly, and they were completely dead. I've started to think the board is just broken, and since a new board is he same as 90% of the cost of an entire new BNF UMX Radian, my plan is to just get a new one and call this one an entire airframe of spare parts. Normally I'm a fixer of aircraft, but this one seems to be a lost cause.
 

Brett_N

Active member
#5
try moving them back and forth a few times by rolling the larger outer gears.

the linear micro servo's get "stuck" sometimes (the potentiometer in them gets confused) and if you're lucky, the rolling the gears back and forth trick will work.

if not, you are SOL.
 

kilroy07

Well-known member
#6
I had a similar issue with my Firebird Stratos (MB look nearly identical)

I ran the servos all the way to the end stops and put just a touch of oil on them (mine was recovered from a tree after... oh, quite awhile in the elements) and then ran the all the way to the other stop (again just with fingers) when I powered it on, the servos snapped to the center position! "YEA!"


 
#7
I had a similar issue with my Firebird Stratos (MB look nearly identical)

I ran the servos all the way to the end stops and put just a touch of oil on them (mine was recovered from a tree after... oh, quite awhile in the elements) and then ran the all the way to the other stop (again just with fingers) when I powered it on, the servos snapped to the center position! "YEA!"


Good to know!! I will certainly try that :)

What kind of oil did you use?? Would high quality bike chain lube work?
 

kilroy07

Well-known member
#8
Would high quality bike chain lube work?
I would imagine, I used 3 in 1 oil (pretty light oil I would say) anything to just help things smooth out a bit I think would help.
(Hopefully yours aren't stripped or missing any teeth)

Looking again, the motherboards aren't identical, but close enough (the firebird has two motors)