I had Futaba S3114 nano-servos controling the swashplate, but had to modify them (they fell in the stock openings), since then I have gone to Hi-tech HS-55 servos, they are a direct-fit for the stock HS50's, although the servo arms didn't quite line up a perfect 90 degrees, linkage adjustments had to be made (on the stock TX-RX system), which mean countless hours flying & adjusting to get the pitch curve/cyclic control working properly again. On a new computerized TX you have sub-trims you can adjust instead.

Shadow