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Old 11-05-2010, 01:17 PM
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Default RE: Hitec Digital Servo Programming

ORIGINAL: mglavin


I'll see what I can do with a step by step explanation, I'll have to get out the programmer and work through it taking notes...

As I alluded to earlier, merely aligning the servo horn perpendicularly to the control rod serves KNOW purpose other than aesthetics… The goal is to center the servo arm in the center of the travel arc, not some arbitrary location with regard to the pushrod. I have some examples (drawings) I’ll try to locate and post them ASAP. Variables with hinge line, hinge line offsets, control horn location, control horn height, depth of or height of servo arm pivot and location all effect the requirements to center the servo arm in its respective travel arc.

Centering the servo arm in its travel arc garners equal throw in both directions at the surface and TX even with the variable anomalies of model specific set-up and the linkage ratios and geometry thereof. The extra steps required to achieve this are not absolutely required but afford the modeler a precision set-up if nothing less. Being able to deflect the joystick twenty degrees in either direction and realize like speed to a fixed deflection in degrees either side of center is again our goal without benefit of software and trims afforded via the TX. The mechanical set-up can do this with all ZEROED out at the TX. Using trims, offsets and curves skews the results and ultimately leaves you with unequal travel volumes and speed of the surface in play.

Thanks for sticking with me and helping. I agree that just moving the servo arm to make it perpendicular with the control rod is not enough. You need to make the new center position the center of rotation and also have equal/full servo travel from the new center. From the laptop I set the new center (perpendicular to the control rod) and then set the new left and right end points. Brendan has informed me that to mirror the factory end points I should set them to 45 deg from center. I don't have a problem doing this from the laptop but, when using the HPP-21 plus without the laptop I am doing something wrong and can't seem to understand the directions that are provided.