500t problems/questions

[etrex]

I picked up a used xl that came with a 500t gyro and an hs 56 for the tail servo.. after a crash I rebuilt on an sa frame and decided to upgrade to the 3400 digital servo for the tail....Now to get rid of the tail wag I have to set my gain very low... about 10 points lower than with the old servo. I went through everything it it is all smooth, and I did change the frame rate to high on the gyro...Now I notice that static on the bench the servo makes a slight hum and chatters a little.. When I plugged in the old hs56 and went to regular servo rate it does the same thing, but if I plug directly into the rudder channel on the rx it doesn' chatter at all...Is this some normal function of the gyro or is it toasted? It flew well with the old analog servo but now it will hardly hold at all.??????any thoughts? etrex

[aaxiss]

the hum is normal because of the resolution of the digital servo. as far as holding it should be alot better with the 3400. I have a similar setup and run about 28% on the gain in HH mode with the end points on the radio set at 150% and the DR at 50% tail is crisp and locked in, Travel set on gyro limiter. Piro rate is pretty fast also.

make sure you trim out your gyro again with the new servo... gain to 100% in HH mode, Trim step at 1 . watch for any creep in the servo and use sub trim to cancel it out. Start out with about 35% gain and adjust from there.

[etrex]

make sure you trim out your gyro again with the new servo... gain to 100% in HH mode, Trim step at 1 . watch for any creep in the servo and use sub trim to cancel it out. Start out with about 35% gain and adjust from there

aaxiss. I did set the subtrim to get rid of the creep, but did not know to go to 100 percent gain to do it, so I will try that. What do you mean by trim step at 1? Not sure I understand that...... also besides the hum, the servo arm is twitching back and forth slightly with no rudder input. enough to move the slider slightly and I suspect this is what is cousing my problem....I will let you know if retrimming helps. Thanx etrex