ORIGINAL: Ilikebipes
Because I have built and flown the Dirty Birdy the thought of using the torque rods would never even cross my mind. It's a big precision plane that will travel at some pretty fast speeds and you could get some control flex with the system.
Gene-
I think the flex issue is related to a few things- but not to the torque rod assembly.
I do not believe plastic film coverings offer the rigid finish. Finishing with fiberglass or fabric/dope I believe helps fix this... as well as building up an aileron from gluing two sticks together and sanding to the airfoil. Sheeted foam would be an even better option.
I don't want the servo arm, push rod, and control horn hanging out in the wind- not that it will effect a whole lot, I just don't want it in this case.
Truth be told, in a classic pattern application,
I believe the torque rod makes more sense. But that is just me and I am really not that important in the history of model aviation, so it can only be taken with a grain of salt anyhow.
tailskid-
I agree with your assessment. It can interfere with internal hardware if the install is not properly pre-planned.
Top_Gunn-
I am assuming a proper application within my reasoning. You are correct that there comes a point where the application just will not make sence... especially in giant scale and jet aircraft.
Brian
Brian,
Not so sure what your issues with dual aileron servos are. If one issue is clean airfoil, forget it. Those gaping holes that retracts reside in are far more disturbing to the air mass. If another issue is weight for a given stiffness required, dual servos and tork rods are possibly a wash. Depends on how long the tork rods are. Stiffness of strip ailerons is inherently small and that doesn't help or favor tork rods. Mini servos today produce more than enough tork for ailerons considering the available tork of the day back then. If we had 40 oz-in we were doing good. Heck a micro servo can deliver that much tork today for around 10 gram weight. If an issue is cost, then I agree, tork rods are less costly up front but if done the way I did mine, they cost time and effort
Having said all that, tork rods can be stiffened up nicely using carbon tubes rather than steel. Back in the day, ca 1985, I used 5/32" carbon tubes and applied a layer of carbon tow around the tubes to keep them from splitting and to a tickness just enough such that the carbon tube would slide nicely inside outer NyRod sheath. I usuallyused epoxy but have also used ca with similar results. Produced a light, stiff and strong driver for ailerons. Sorry no photos, but I think the description should be self explaining.
Merle Hyde was the first guy I recall who put dual servos in the wing, late 80's early 90's, I think....Around the same time frame I remember installing tork rods in one intermediate sized model with plug in wings and driving each tork rod with separate servos. It worked fine but why even go there? Too heavy for certain