THEMA:

Hi,

did you try a calibration ?

Regards
PW

Hi,

one question:

which TX and RX software version?

Regards
Peter

Hi All,

So, here is my progress (quick summary - I believe the transmitter is not to blame).

Between flying sessions, I performed some experiments varying the ambient temperature of the transmitter from 10degC to 30degC - no change in the rudder or throttle setting of 8%/-98%. I also did some supply voltage tests with the same result.

Then, finally, I had the problem when flying - and sure enough the transmitter was still reading 8% on the rudder. (1 trim click right takes it to 9%, three left to 7%.)

Back in the workshop, I happened to find my Occam's Razor ( en.wikipedia.org/wiki/Occam%27s_razor ) and pointed it at the model. I rigged up a pointer on the fin/rudder fine enough to be able to see three clicks of trim; then grabbed the servo itself and twisted it hard. Sure enough, the servo could be moved a tiny amount on its grommets, amounting to about 4 clicks of trim offset. Twist it firmly the other way and it would go back to its original position. So my latest theory is that a sharp side-load on the tail wheel during landing or take off is enough to shift the servo on its grommets.

I have now replaced the grommets, inserts and screws (and applied a fine smear of silicone grease to the grommets), checked the servo is clear of the bearers (it was/is) and reduced the closed loop tension a little. And now we wait...

If that was the problem, I shall be suitably embarrassed

Hi,

thank´s for this info.

I sent all to Jeti; good to hear that it is not the radio. Jeti also did again some temperatur tests; but no problem with the radio .

Regards
PW