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Old 08-17-2016, 12:22 AM   #38 (permalink)
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Join Date: Mar 2013
Default K120 Servo Saver Mod

A servo saver mod allows the collar of a servo arm to expand when it takes an impact so it can slip on the servo shaft and reduce stress on the servo gears. The O-Ring on the outside keeps it from expanding too easily and slipping in flight or on very minor impacts.

After you cut a slit thru the servo arm collar so it's a 'c' instead of an 'o', install a 007 O-Ring or X-Ring around the collar. It's a slightly tight fit, and keeps the collar from expanding too easily and slipping during hard maneuvers, but stretches to allow the collar to expand and the arm to slip during a crash. A 006 X-Ring or O-Ring is a tighter fit and will slip less often, but transfers more impact to the servo gears. I am currently using 006 X-Rings because I have spare servo gears on hand so occasional gear damage isn't a big issue for me.

I don't do the servo saver mod on the K110 or V977 and have never damaged a servo after hundreds of crashes, but everybody crashes differently. I usually crash these because I bog the motor. I rarely crash hard as the heli is de-accelerating right before the crash, just not de-accelerating hard enough due to the bogging.

007 O-Rings:
007 X-Rings:

006 O-Rings
006 X-Rings

K110 2S, K130, HCP100S, 180CFX, T-Rex 250 & 450, V120D02S, Master CP BL, V200D03, V911
Devo 6S 7E F7 8S 10 12S F12E Deviation, Taranis X9D, T8J, 9X, DX6i, Phoenix 5, RF 7
Team Pilot: MallHeli FireDemon
Extreme Air Ninja 3.6 Channel

Last edited by BirdBarber; 08-19-2016 at 11:15 AM..
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