I am not finding the spec for the servo arm ball link measurment for a 600 E.
Can anyone tell me how far from center the link should be?
I am using Spectrum DS821 servos, are the standard arms strong enough?

Thank you.

I used futaba servos. followed guidelines on page 19 and 20 of the manual. Since the servo arms are pull-pull setups, it took quite a bit of adjusting to get the servo buzz under control especially the fwd/aft cyclic.
All i could really do was ensure the servo linkages were as parallel as possible, then adjust linkages to stop the buzzing. It was a pain in the @#*$*%&.
Maybe someone else has a better way. good luck.

No way I'd use those servos on a 50.

read some treads on the DS821s ... they will brake their output gear shaft to the servo horn . I am putting Futaba s9451s in my 600CF

Something else I set mine up so that all measurements are equal and level. So that ball are adjusted in or out on the arm to insure they are level with the ball on the control arm. Also as stated earlier adjust to eliminate any binding between linkages. If one is just a little bit longer or shorter it will "buzz"

What servos would you recommend? I am not into heavy 3D, just sport flying.
These DS 821 servos have a fairly high torqe rating, are they weak in the geartrain?

What about the measurment for the balllink from center? Should that be the same as the bellcrank?

They have been failing frequently, the output shaft shears off the top and the amp dies. They seem prone to vibration and according to JR are ok for a 50 size electric. Personally I wouldn't put them in anything that costs more than the servos themselves. The one I saw let go was on a 40 size airplane with 1 servo on each wing, not over powered and not set up for 3d. I just dont think its worth the risk on a heli that size.