RE: Futaba and Hitec output shafts, same or not?
I can verify that splines will slip. Fortunately the slip was discovered during testing and before flight. A spline slip during flight would be very bad.
Fortunately Futaba horns are a different color. It is harder to distinguish the difference between JR and Hitec horns.
I found Hitec, Hobbico and Tower horns to measure .220” across the diameter of the hole in the horn and to have numbers on the horn. JR horns measure .233” to .235” and do not have numbers. Someone else might be able to verify my findings.
Bill