E5 tail wag help

[Stang Man]

Okay guy I wanted to ask here, just incase I'm missing something.

I have a stretched E5 with Align DS615's and a DS650 on the tail, it also has a Skookum SK540. Out of the blue it started a fast tail wag that seems to get worse with higher head speed.

I rebuilt the tail with all new bearing and went over all the mechanics and the tail is buttery smooth, but it didn't help.

One thing that is strange is if I spool up on the bench without main blades the wag is gone.So I don't think its the tail.
Could a vibe in the head/main blades cause the tail to wag, or should I look at something else?

I was also considering replacing the tail servo, but I wanted to ask here before I dropped the coin.

[Rodney Kirstine]

Are you using a governor?

[Stang Man]

Yes, I'm using the Skookum Gov.

[Rodney Kirstine]

As a quick test, you could turn the governor off and run throttle curves. I've had governors cause fast tail wags. Also, when I ran the Skookum governor, it wouldn't activate on the bench without blades because there's no load on the motor, so that could explain why you don't see the wag in that situation.

[Stang Man]

Okay thanks I'll give that a try.

When I change from idle 1 to idle 2 I can hear the head speed change, doesn't that mean it's working?

[Rodney Kirstine]

Been a while since I ran a Skookum but assuming you use different throttle percentages for IU1 and IU2 it will change head speed even if the governor isn't engaged.

[Chris Sexton]

Originally Posted by Rodney Kirstine

As a quick test, you could turn the governor off and run throttle curves. I've had governors cause fast tail wags. Also, when I ran the Skookum governor, it wouldn't activate on the bench without blades because there's no load on the motor, so that could explain why you don't see the wag in that situation.

+1 gov gain being too high can cause this.

Also, I have had troubles with that tail servo before. Try everything else first, but keep in mind that tail servo may be having trouble too.

[Stang Man]

Thanks again guys! The gov gains makes the most sense. It's just strange that the tail was fine one day and out of the blue the wag shows up.

[LoveToFly1]

yea, I am actually leaning towards the tail servo myself. not there one day then there the next.... the only thing IMO it could be (since you have rebuilt the tail) is the tail servo.

unless you have changed head speeds, bc head speed can cause this as well.

[LoveToFly1]

well, not really cause it, but it can require a lower tail gain at higher head speed, so if you increased HS, then you may need to lower tail gain. make sense?

[Stang Man]

Well it turned out to be the gov on the Skookum. Switched to the governor on my hobbywing, all is good now.

Thanks a lot guysI would have never figured that out on my own!

[Rodney Kirstine]

That's great!

[Digger1973]

Just getting back to flying after almost 2 yrs. My e5s has the same issue and i believe it is in the sk gov as well. Flew great prior to stretching and a weaker motor. Going to play with it more once i get time through the week.

I forgot how much fun i had with my E5. Really glad i decided to fly it again.

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