Servo jitter

[mickelsen]

I've got all the servos and devices hooked in my Seaview SD. Everything works pretty good except when I turn the motors on, I start getting some jitter on some of the other servos, primarily the rudder servo. Can you give me some suggestions as to where I should start looking to solve this problem?
Thanks

[He Who Shall Not Be Named]

I've got all the servos and devices hooked in my Seaview SD. Everything works pretty good except when I turn the motors on, I start getting some jitter on some of the other servos, primarily the rudder servo. Can you give me some suggestions as to where I should start looking to solve this problem?
Thanks

If you're using the WFly receiver ... that's the problem. We recommend using the Sombra Labs receiver in the tight confines of a 2" SubDriver.

David,

[mickelsen]

I'm using a Tracker III Tx, and I have both Seeker 6 and SL-8 Rx's. It happens with both.

[He Who Shall Not Be Named]

I'm using a Tracker III Tx, and I have both Seeker 6 and SL-8 Rx's. It happens with both.

Those are fine receivers, you've done good so far.

OK then, one of two things is going on:

1. Either your rudder pushrod is experiencing too much drag through the watertight seal or ...

2. You have a bum servo (bad feed-back potentiometer would be my guess)

First, disconnect the pushrod bell-crank from the rudder servo and see if the 'jitters' goes away -- if so, you have to bend the pushrod a bit till it presents less drag through the seal as you operate the SD and rudder servo.

If after disconnecting the rudder pushrod from the servo and the servo still 'jitters' then you have to replace the servo. Replacements available through the Caswell catalog.

David,

[mickelsen]

I have an extra servo so I just unplugged the rudder servo in the brick and plugged in the extra servo. The jitter disappeared. Bingo! I have to replace the rudder servo.
That makes two servos that I have to replace. The ballast servo is also bad. Replacing it without removing the bulkhead to do it should be interesting. Nevertheless, things are slowly getting pulled into shape.
Thanks.

[He Who Shall Not Be Named]

I have an extra servo so I just unplugged the rudder servo in the brick and plugged in the extra servo. The jitter disappeared. Bingo! I have to replace the rudder servo.
That makes two servos that I have to replace. The ballast servo is also bad. Replacing it without removing the bulkhead to do it should be interesting. Nevertheless, things are slowly getting pulled into shape.
Thanks.

As for pulling the ballast servo:

1. Within the ballast tank loosen the two wheel-collar set-screws (catch and set aside the wheel-collars when you pull out the servo)

2. Unscrew the two servo bracket retaining screws (long handle screw driver -- get inventive with some K&S tubing here)

3. With a long hemostat, grab the servo case and pull it out of the cylinder

Installation of the new servo you can figure out. Don't forget to coat the servo bracket retaining screw threads with some RTV to insure no water gets past the threads from the wet-side of the bulkhead.

David,