Stripped servo?

Geronimo

Active member
I've put one flight on this new plane, and I took it out this morning to find that the elevator servo is skittering like crazy under a light load. So back home we go. As far as I can tell the control rod is free and moves decently. It's a new servo from the FT Power Pack C with one 3-4 minute flight on it, and no crashes.

So how do I replace a servo that's hot melt glued on? I was afraid these planes were pretty much disposable, but I'm just wondering if there's a way to do it without creating some significant "authentic battle damage" in the side of the fuselage.

Also, any recommendations on a quick servo replacement that's decent quality?
 

Merv

Site Moderator
Staff member
You have 3 choices, mechanical, heat, chemical. Most of the time, I will take a hobby knife and cut out the old servo. If you do it carefully, there will not be too much damage. The new servo will fit in the hole. You could use a heat gun or hair dryer to soften the glue. Rubbing alcohol will loosen the bond, give it a minute or two to soak in.
 
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Geronimo

Active member
You have 3 choices, mechanical, heat, chemical. Most of the time, I will take a hobby knife and cut out the old servo. If you do it carefully, there will not be too much damage. The new servo will fit in the hole. You could use a heat gun or hair dryer to soften the glue. Rubbing alcohol will loosen the bond.

I forgot to mention that it's glued to the inside of the fuselage. Cutting it out means making a patch for the side, which I'm probably going to have to do. I'll try the alcohol first, thanks!
 

Geronimo

Active member
So I got the servo off (thanks Merv!) and opened it up. The tiny little drive gear right off the motor gear lost a tooth. Bummer! Everything else looks and works great. So I need a new servo.

I was reading some other threads about these 9g servos being unreliable. I guess we just roll the dice and hope for the best.
 

Merv

Site Moderator
Staff member
I was reading some other threads about these 9g servos being unreliable. I guess we just roll the dice and hope for the best.
Ive been flying planes a long time and have learned that all servos break. The size and cost of the servo matters little. I buy mine 10 or 20 at a time, much cheaper in bulk. Now WHEN they break I always have a spare ready to take its place.

Metal gear servos are a slightly tougher, however don’t use them if you have any kind of stability or flight controller. The constant micro correction will wear them out prematurely. They will develop a lot of slop rather quickly. For this application, plastic gears wear much longer.
 

Geronimo

Active member
I have found these have been working very well for me, they are 2-3 grams heavier but being digital, all metal gear and will run on 6 Volts is a big plus to me. I have many of the plastic 9 gram servos that have been working well but these in the right circumstance ( tail wheels ), 3D planes, large control surfices, they perform better.

https://www.aliexpress.com/item/32977425392.html?spm=a2g0s.8937460.0.0.8a0d2e0epilaJ6

Thanks a bunch!! Since it was my elevator servo that went wonky on me, I'm wanting something reliable for that. I can probably manage with one aileron (as long as the other one is neutral) or losing rudder, but not the elevator. I couldn't believe how squirrelly the plane was behaving, and it never occurred to me that it could be a servo. In all the years I flew .40, .60 and 1/5 scale RC, I never had a bad servo.