mCPX - 130X - nCPX shakes? How to clean Blade linear servos

2:43 PM giovanni 0 Comments


Have you ever experienced the famous "shakes" when you hover your micro helicopter, being that any chopper that uses linear servos (Blade mCPX, 130X, mSR, nano CPX, Walkera 120D02, ...)? 
Well there are a few solutions to this problem, but the most common, and the one that helped me out almost always is...
Clean your servos.

Linear servos basically work with a wiper sliding on a metal strip. This friction causes some grit to deposit both on the wiper and the strip. When this happens the signal is not clear anymore and the 3 in 1 will struggle to center the servo, causing the shakes.

You might have heard someone saying: "just clean them!" and maybe you are a bit afraid of opening up such a tiny and expensive part of your heli. Well, fear no more, this article is for you!


First thing to do is to remove the canopy and expose the electronics

Then go ahead and with a pin disconnect the three servo connectors

In my case I took the 3 in 1 off too, but there is no need for that, just carefully unscrew the servos from the frame

Be careful and remember which servo was where, you don't want to reassemble your heli with like new servos to find out you have to align the swashplate. I usually orient them so that, tail in, the left servo sits on the left of the frame, and so on. Also try not to mix up the pushrods, for the same reason as before.

Now this is when you have to be EXTRA CAREFUL. Remove the four tiny screw that hold the slider on the board and gently separate them to expose the wipers and the strip. Then with some alcohol gently rub the strip and the wipers. When you clean the wipers do so following the direction of the tiny flanges, be careful not to bend them. 
Repeat the same operation for the remaining two servos, reassembling them after you cleaned them.


And voilá, that's it! This picture is to show that the connectors on the 3 in 1 follow the same logic we used to place our servos on the table. The connector on the bottom left is for the left servo, the middle one is for the elevator and the right one is for the right servo...