Originally posted by wildblueyawner
Hate to crash your party, but changing control linkage setups will not affect the total electrical energy consumed by the servo, thus will not extend flight time (with a caveat below). If you’re experiencing longer flight times following your linkage mod’s, it’s for some other reason or variables not accounted for.
First the basics - Current drain (amps) depends on torque, not servo travel. Electrical energy consumed is the product of current and time (amp-hours), but since time depends on the distance the servo travels, the energy (work performed) can be equated to the product of torque and the angle that the servo sweeps as it applies that torque.
The kicker is that you can't get energy from nowhere - Output torque and servo travel are inversely related – If you decrease load torque by changing the lever ratio, the servo has to travel proportionally farther (just like with gear ratios). No matter the configuration of the linkages, no matter if they’re linearly or non-linearly associated, no matter how they’re related, the mechanical work required for a given control surface throw will be the same, thus the electrical energy (amp-hours) consumed will be the same.
Now the caveat. From a physics standpoint, the above applies, however from a real-world engineering standpoint, reducing the load on the servo may be justified if, for example, the servo is running hot due to high torque, causing inefficient operation and associated high current drain vs. output torque.
Effective ways to decrease battery drain (for a given aircraft and control setup) include the old standbys:
1) Reducing friction and binding as much as possible: pushrod friction, clevis binding, misaligned control horns, hinge friction caused by warped control surfaces, misaligned hinges, glue in hinges, etc. Friction is (generally) the enemy.
2) Ensure that servos don't go beyond the limit of travel of the control surface. Stalling a servo is the worst (sky high battery drain plus heat). If your radio has it, adjust EPA’s accordingly.
3) Avoid unnecessary servo motion - Re-assess how many control functions you need, and whether they really need to be mixed or coupled. Also smooth flying, not bang-bang hardover stick action, but that comes naturally with experience.
Thats exactly what I was going to say!!!!heehee....