Torquestar,
Eyeballing and trial and error, is something we all go thru, with each heli, and as you case changing out servos. I just changed one out on my HBK2 tonight. After getting it all back together, make the intial setup/eyeballing and make a test flight/hover. And make necessary adjustments. Get it as close as you can with all the trim levers in the neutral position.
Dave / Choppersrule
ORIGINAL: Torquestar
i'll bow to both of your experience and change them out. better safe than sorry! i'll order a few more s75 gear sets just in case. i'm a little intimidated by changing all the servos since I don't really have the experience to know how to properly set up the swashplate linkages, other than eyeballing and trial and error.