rideon67

My Feedback: (1)

The Hobbico CS150 digital servo on the rudder of my OMP 540 Edge is searching for center and will not stop jerking back and forth until I grab the control surface or put a load on the servo. Once it is stopped at center it will start jittering again if I touch the rudder. The vibration of the engine sets it off so it searches continually when running.

All the leads are soldered and run down a channel in the fuselage with the elevator leads (hitec 5645s) and the jitter is present with a different Tx and Rx. No jitter on the hitecs. I'm running 6v and 100% travel with a pushrod system.

Hobbico tells me they will not replace the servo even tho it's never been flown because it sounds like a mechanical problem.

Am I missing something or does this servo need replaced?

ramduster

My Feedback: (2)

Hi rideon67 does the servo jitter all the time or does it stop after the battery volts drop some. I have a Jr servo that will jitter some when the battery is just off a charge but when the volts drop all is OK. I am also thanking about getting some of these servos but if there are problems with them I may look for some thing else. also where do you fly at in piedmont.

rideon67

My Feedback: (1)

The jitter is intermittent but not related to the battery charge state. The surface also jitters when moving. I put this servo on the elevator, changed Rx channels, separated the lead away from the elev leads and tried everything I could think of. This servo is crap. The plane is all apart now --------- replacing with Hitec 333 in-oz. No more jitter.

I fly at BRRC. Too hot lately tho.............

ramduster

My Feedback: (2)

Yep I fly at BRRC also and I know what you mean about being too hot. Good to hear about the servo because I was just about to buy some.

BaldEagel

Does it jitter when disconnected from the rudder, if it does its a faulty servo, if it does not and you are running a closed loop system it may be the cables are too tight.

Mike

Hooked-On-RC

My Feedback: (16)

Yes sometimes on a pull pull system the cables may be too tight and the servo will hunt for center becasue of the cable tension. You can eliminate this issue by using a bellcrank on the rudder and let it take the cable tension.

rideon67

My Feedback: (1)

The jitter occurs only when the servo is connected to the rudder (by pushrod, not pull/pull cable). There is some gear lash in this servo and I suspect this slop along with the mass/momentum of the moving rudder is creating a overcontrol in the servo deadband.

When I replaced this servo with a Hitec 333 in-oz the problem went away. I sent the hobbico back but am not holding my breath...........