Weird servo feedback under load

[Tbos]

Hi.

I'm in the process of putting a PA Katana mx together and ran into an odd servo issue.

When moving the rudder, the servo seems to be pushing back against the direction of movement specified by the transmitter.

https://youtu.be/ANlGt8BSMNU




All of the servos do this to a certain extent, but the rudder is the worst offender.

These are hitec 8085 mg servos and a spektrum ar6210. I've tried powering the rx off of both the bec and a receiver life pack.

Any help appreciated.

 

[Xpress]

Cycle the servos a lot, especially if new. Sometimes they just need to 'break in'.

 

[Tbos]

I'll give that a shot. Thanks.

 

[Tbos]

No luck with that. I'm going to assume it's bad and replace it.

 

[Xpress]

Give us a call:

858 748 6948

 

[Tbos]

Thanks. Did that and talked though some troubleshooting steps.

I'm waiting on a replacement to come and I'll send the weird one back for repair if it turns out to be bad.

 

[Tbos]

By the way, it was awesome to make a call to a vendor and have someone knowledgeable on the phone in under 30 seconds.

Thanks again.

 

[Xpress]

You are welcome :thumbup:

We make it a point to stand behind our products.

 

[Tbos]

So I tried a new servo (5085) today and it acted exactly the same.

Since the rudder moves so smoothly I'm going to assume it's a lack of load that is causing it.

If I apply load to either the rudder or the control arm and the vibration goes away.

I guess I'll go fly it.

 

[Xpress]

Interesting... Do report back how the airplane flies.