View Single Post
Old Sep 28, 2012, 01:30 PM
2Doggs is offline
Find More Posts by 2Doggs
just gotta mess with it!
2Doggs's Avatar
North West Louisiana
Joined Nov 2009
6,152 Posts
maybe both - the servo will respond to changing pulse widths, with most using 1520us at neutral, and about 500us either side of that. The pulse width sent to the servos will depend on the RX, but maybe the gyro can modify the signal to the tail servo. Perhaps someone a bit more knowledgeable in digital electronics will chip in...


OK, I did a test using the CX program box, which also functions as a servo tester, and a retired Corona 929MG servo.

First of all, I set both CX3x1000 tail limits to 100. Full rudder deflection then resulted in the servo arm moving maybe 40 degrees either side of centre. On the servo tester, it seemed to correspond to 1130us to 1910us - though I was only judging this by eye for the servo arm position.

Setting the controller tail limits to the maximum of 125 resulted in servo arm movement of a little over 45 degrees either side of centre, and on the servo tester, I could replicate that by going from 1020us to 2020us.

Therefore it seems that tail limits set to 125 will result in the maximum normal amount of servo throw.

One interesting result of these tests is that, for my radio at least, which is a JR9XII with a 2.4G FrSky module and RX, adjusting servo trim in the controller moved the servo neutral but had no effect on the servo end positions. That means that using large trim values in the controller will inevitably result in differential servo throw, something to be wary of in the cyclic servos.
2Doggs is offline Find More Posts by 2Doggs
Last edited by 2Doggs; Sep 28, 2012 at 02:04 PM. Reason: Update
Reply With Quote