2017 550SX servo fit

Hey all - running into trouble with my Xpert R2 servos on new 550. If I run spacers on elevator servo, and remove one spacer nut off servo horn ball - the horn hits top of frame where anti-rotation brackets fits. If I hard mount servo without spacer, it clears, but then the control rod is not even close to 90 degrees to main shaft. How many have had to trim the frame for figment?

Also, I’ve had to file a bit off frame where aileron servos install, as the grommet on Xpert servo (where removeable cable installs) won’t fit through cut-out. This normal? I’m fine trimming, but seems I’m doing an awful lot of it on this build.

Hi,

well, there is no standard about servo sizes. But I wouldn't worry too much even if the links are not 90°, you will hardly notice it in flight.

If everything's set up as straight as possible, and the swash plate is level with as little electronic trim as possible, recommended angles are set, you are good to go.
Do the trim flight to adjust for the last bit, in flight. It won't get much more precise, the helicopter does not care for exact angles on the ground, there are so many dynamic effects.

I am pretty sure you will be happy in fact I think we mess too much with perfect angles on the ground, I myself prefer a more down-to-earth setup with only a little measuring and a good part of eyeballing

I mean, a good symmetric setup is the basis, no doubt about that, but e.g. the slight offset from 90° on the links does not do much bad, does hardly change the angles on the swash plate/blades, and it might even help compensating a little for the effect of the servo arm moving in a circle and the link supposed to move up and down straight.

Cheers

Eddi

Born to fly ...
forced to work.

Thanks Eddi! I see you mentioned this before, but can you foresee issues using a washer on servo horn instead of small nut? This gets my spacing for control rods a bit closer to parallel with main shaft.



Edited 1 time(s). Last edit at 04/22/2018 07:42PM by Ty89m.

Hi again,

no, I see no issues, the ball link is free enough and it looks mechanically sound to me.

Kind regards

Eddi

Born to fly ...
forced to work.