FlyBoy 2000:

No disagreement with all the comments so far on this thread.....they all sound legit to me......... but when I was building my KC 1 year ago, I had several N.I.B. 8411's and wanted the 2721's for another project.....I now have over 100 flights on my KC......zero flap problems....I use all digis on my KC, except for N/G steering(2721) most flights off grass and still works fine..... and UP-6 brake valve(341)

I set up all of my servos with an in-line ammeter to be sure there is no high-current drag or stalling occuring at any point in the travel......I have found 8411's pull just a little more current than a 2721.....now the 8611's are a different armadillo.....they can pull big mama amps when you drag or stall them.....

Another saving grace is the fact that with the KC linkage set up the way it is, and with the long live hinge line (no where near as tight as on my SuperBandit)....... there is inherently enough slop to prevent any stalling at either end of full travel, unless you really screw things up......you don't really have to bang the flaps up tight with the servo when you set them up, as airloads do that for you, for the last 1/16" or so of travel.......

While the 2721/4721 remains a great servo in selected applications, it really is getting long in the tooth......the output bearing and flimsy case top design really belong in the 1990's, as does the analog technology.....the Giant Scale gurus know all about this....when they want to hold that monster rudder rock steady on their 50% Edges, in both full push and full pull, or hold that elevator rock still with 60 degress +/- of travel, they gang 8411's or 8611's not 2721/4721........

I use an SR 2200 RX pack with no regulator......my UltraDuo Plus records about 400-450 maH consumption for an 8 minute in-the-air flight, so I think current draw is well within safe range.....

Just my dumb***** opinion......

Tom