Since the X20-2208 and X20-1305 is only the same servo but with difference gear ratio to gain more speed or torque, so I only talk about the X20-2208 in this review.
First look of the servo and its accessories:
The servo comes with a full set of plastic arm, also the rubber servo holder and screws.
It also comes with a normal metal servo arm and a creative metal servo arm. This servo arm allows for continuous fine adjustments of the angle just by loosening one screw. And it may also protect the servo gears in a crash.
New metal servo arm:
And here is the servo with closer look:
The grooves on the case provide better cooling in the extreme conditions and reminds me about the MKS X8 series.
Very well finish metal case.
Let’s open it to find out what inside this beauty:
Just unscrew four screws in the bottom of the servo, you can open its case easily. The servo uses 4-stages drive train just like the small KST DS215MG
KST also uses two O-ring around seams to keep moisture out of the servo, but in case you crash into water, I believe this design would help a little bit too.
Open the bottom case, you will see the servo circuit board. You also can see the the wiring is glued down at both ends, to prevent the short-circuit between the board and the metal case. It also protect and prevent the wire loose from the board.
Next thing I do is testing how precious this servos is. This is how I setup the test:
And below is the test video:
Another question that we always want to know, that is about the amp draw. That’s why I made the test below:
I try my best to rotate the servo arm, but I cant, and the maximum amp draw is only 2.63A maximum in the test so I believe there is no issue to power it with 10A BEC.
Over all, this is a really good servo with great specs and well design. KST also said that unlike any other servo, the X20 generates no counter EMF in any working condition as it has the all-new design servo circuit board, so your flybarless system and receiver will not be interfered or have any weird behavior any more.