Most of my recent experience is with Align ships and torque tubes. My 600 EFL Pro has the most locked in tail I've ever had. So, maybe I'm a bit spoiled. My E7 has some tail wag at hover. Maybe a 1/4 to 1/2 inch or less. It is not constant and seems to come and go a bit but it is present about half the time I'm hovering. Maybe it's tied to collective stick movement.
My setup is Hacker 470KV 14T pinion, CC 110HV on set RPM at 1900, 2000 & 2100 rpm. The BLS 251 tail servo horn is in the last hole of the Futaba 4 arm horn and the Vbar numbers are right around 100 for travel and I'm not over-traveling the slider. Vbar rudder gyro is about 80-85. The mechanical tail control parts feel smooth and easy to me. I started with Gov gain at 8 and if I move it down to 1, I can significantly reduce the wag but not entirely get rid of it. I don't think running the gov gain at 1 is a good option in the long run. Belt tension is certainly not on the loose side, although I have tried it a bit looser with no difference in wag.
Is it unreasonable to expect a belt drive tail to be as locked as a torque tube? My Compass 6HV, also belt drive, did this same kind of wag although it was much worse. The tail control on that ship was not good with plastic hinges and metal pins for pivots.
My friend Ray Nemovi built the E7 airframe and I did the mechanical and electronic setup. I supplied him with some silicone spray and he assured me that he used it on the belt. The ship has maybe 15-20 flights on it now. Would it be worthwhile to give the belt another silicon bath? Suggestions and comments welcome. I'd sure like this beauty to hold the tail still when hovering.
