NX4 w/ Mini V Won't Piro Flat

[hoblium]

Actually, as soon as I give any rudder input, it drifts backward (tail drops).

So far I have made sure swash is level (it is, climbs out flat both upright & inverted, and has almost perfectly matching pos & neg pitch) and fixed my crummy CoG (added almost 60g of lead weight evenly to the front, removed the header tank, etc.). It is now actually a little nose-heavy, especially near empty tank.

Does the V-Bar drop tail when there are excess vibes (I had a BeastX that used to do that)?

Needless to say it's a little frustrating!

Details: Super Combo with Gaui Servos, Gov, PushGlow, Mini V (2 Spek Sats) and yes I have the governor functioning properly.

I am ready to ditch the VBar and go with my go-to FBL (iKon)!

Suggestions? Anybody?

[S.Millar]

Did you use the supplied metal plate under the Vbar to isolate it from the motor vibration?

[hoblium]

Originally Posted by S.Millar

Did you use the supplied metal plate under the Vbar to isolate it from the motor vibration?

I did, yes. It does seem like the answer would be vibes, but my not-so-scientific method of looking at the vertical stab for shaking tells me the drive-train is pretty smooth.

Maybe I will throw an iKon on there (since my Atom is benched currently) and see if that works any better.

Still open to suggestions though!

[Glenn Goodlett]

Check your vbar logs. Get a BT module and run the spectrum analyzer in flight to check vibes.

I don't know if you need the pro upgrade for the mini or not to see the logs and/or the spectrum analyzer.

Has the tail ever hit anything? Those tail hubs bend easily.

[Hot Apple Pie Guy]

Did you do a 'optimization' flight before or after correcting CG?

I always thought CG was the main culprit for wobbling when piro'ing...

Mine have never been perfectly smooth, but I've seen pros piro'ing inverted over grass 1" off the ground without a single bobble... Always impressed me, and told me I need to work on my Fbl tuning skills... Lol

[hoblium]

I didn't do an optimization flight, no. I will give that a try.

Not sure about Mini V having vibe analysis, but I will look into that also.

Thanks guys, I will report back.

Sent from my HTC One using Tapatalk

[Hot Apple Pie Guy]

Vbar is pretty cool for having optimization flights... I do the tail and head optimizer a separately... Preferably in a low/no wind situation... If there's no wind, then you can also do the auto trim flight...

Have you ever done those before? There's tricks to them... Research it if you can... It's all about performing quick stops, both directions, full rolls to quick stops etc... Each time I do it I get better at it... But, after initial attempt I typically don't go back and do it again , so it's been a while since I've tried...

[DaveLister]

My NX4 bobbled while piroing when I had my head dampers worn out. There was a lot of play between feathering shaft and head which probably prevented vbar from compensating fast enough.

I swapped the damers for the red ones, but still had some play as the feathering shaft was too long to press them in correctly. As I didn't had any suitable washers, I dremmeled feathering shaft a little to make it shorter and that fixed it. Now I can even piro inverted an inch from the ground no problem.

[hoblium]

I am redoing the entire set up first and fixing my pro license so I can do the optimization flights.
We'll start there (actually hoping something was wrong in my set up and a fresh one will fix it).
Thanks again for all the suggestions, I will report back!

Sent from my HTC One using Tapatalk

[hoblium]

Yay, finally got the chance to take her out today and apparently I did something wrong in the setup before (thinking the swash wasn't really level).
Flew beautifully today and a LOT of fun - my first nitro, woot!

Via TapTalk & My Nexus 7