V-Bar Tail Tuning and Troubleshooting Guide with Mikado Logo Example

[OverTemp]

Directly, only with Express.

Indirectly, using bank switching, with Pro.

[MrMel]

Actually, in Pro it can be directly too, under bankswitching dropdown you see "Aux -> Tail gain"

[OverTemp]

Sweet!!!!

[Dandion]

Hi guys
i am playing with the Vbar settings for couples days and can not get rid off my slow tail wag.

My set up is :
Synergy E6, YGE 90HV, Vbar pro 5.2, YGE Governor.
P gain:80
I gain: 68
Gyro gain=92
Precomp: collective=18, cyclic=7

Problem:
When i hover (tail in), the tail wags slowly and the tail tends to move to the right very slowly with hands off on the TX. I must give little left rudder to bring the tail back in front of me.

Other than that, the heli flies fine but it would be better without this little tail wag. If i increase I gain., the wag increase. If i reduce the I gain, the tail is to soft and i do not like it..
Please, feel free to comment:
Daniel

[tmafra]

Im having the exactly same problem with my x5.

While flying its almost perfect but i can see the slight wag while flying backwards. A bit annoying

[Dandion]

i soldved my problem by giving more pitch to the tail blades. You could set correctly the tail by using the normal mode in the vbar. Once you can hover the heli without touching the rudder stick, go back to header hold.

Now the tail hold very well. Good luck

[BakedMopar]

I just recently have this problem on my 7HV after I swapped motors. I'm not sure if this is motor/heli related or V-Bar related. On CCW pirouettes it makes a stuttering noise. I tried changing gains on tail, checked mechanicals on the tail, lowered and even turned off the governor and I still have this sound. Any ideas?



[ame]http://www.youtube.com/watch?v=-AQmfEy9WaI&feature=youtube_gdata_player[/ame]

[Dafics]

Full size Vbar with 5.1 on a Trex550 V1........

Purchased the complete package secondhand but have just started from scratch with Vbar setup.

Cyclic nice..... set the tail in rate mode to adjust pushrod...OK When switched to HH mode the tail had a twitch (2 or 3Hz). Tried changing tail gain via the slider and directly in the advanced mode...... but really don't know if we were changing the right parameter in the right direction (tried both ways on some).

Suggestions?

PS
The tail seemed to fly OK and I haven't finished going through the mechanical checks although the previous owner didn't mention any issues.....

[stopper]

When I do the tic toc it wags its tail right and left.
what should I do to eliminate the problem.

[Justin Pucci]

Stopper,

Your tail gain is probably not optimized yet and is too low. Go back and run through the common gain tuning procedure that I describe in the original post or MrMel has in his videos and then report back. Good luck!


Sent from my iPhone using Tapatalk

[Rob43]

Hoping someone can offer some thoughts on my tail setup. It's the new tail for Compass 7HV. One of my friends is also running JR 8900 servo on Vbar as well. His settings include a very high Collective Precomp value - 50. My tail sounds "angry", and is much lower Common gain. Here's the link to the post I made in 7HV forum with the Vbar file. Note how low my common gain is - 45. Still have some slight tail kick from a hover, and it sounds angry from hard piro stops from CCW. The tail is making a buzzing sound all the time and never did before. Running Compass 115mm tail blades, JR DS8900G. It's almost perfect except for what I mentioned. It's almost dead steady in a hover, so maybe not too far off.

LINK to Posted Settings

[MrMel]

Originally Posted by Rob43

Hoping someone can offer some thoughts on my tail setup. It's the new tail for Compass 7HV. One of my friends is also running JR 8900 servo on Vbar as well. His settings include a very high Collective Precomp value - 50. My tail sounds "angry", and is much lower Common gain. Here's the link to the post I made in 7HV forum with the Vbar file. Note how low my common gain is - 45. Still have some slight tail kick from a hover, and it sounds angry from hard piro stops from CCW. The tail is making a buzzing sound all the time and never did before. Running Compass 115mm tail blades, JR DS8900G. It's almost perfect except for what I mentioned. It's almost dead steady in a hover, so maybe not too far off.

LINK to Posted Settings

Might be that you overthrow the blade and they stall, try LOWERING your endpoints and see if it helps.
Precomp at 50 is too high.

[Rob43]

Thank you for the suggestion. You suppose drop it to 100/100 from 110/110 would help? Or more so than that?

[Rob43]

To clarify, my precomp isn't 50. Am at 30.

[MrMel]

Instead of just go by chance, take a few pictures at min/max where you see the angles of the blades and I can tell.

[Rob43]

Having a closer look, no doubt stall was a possible cause for blowout. With full pitch range, there was about 45 degrees of pitch at the full travel. I reduced it to 80 slider values from 110 each direction. The pitch is still a great deal, but surely less chance of stall. My JR servo horn has a 14.5 mm setting which is perhaps still a bit too much for best setup. I seem to recall my Spartan tail gyro days where around 11-14 was the best range for best throws for control, Not sure, but I can't see why it would need to be more for Vbar. On the other hand, too little will worsen the tendency of tail kick from collective pop. I've made substantial adjustments this evening, but didn't save the file as of yet. I was mainly attempting to tune collective precomp to achieve a steady tail with collective pop from hover. It appears to be a tricky balance to seek. I can tell 25 is too much. It wags to the left with blade rotation, so it's too much. I reduced in increments down to 9, and believe it was kicking right. Not sure I can dial it all out. Unsure if my JR 8900G is capable or not. It's a very small kick, so not sure it's worth chasing or necessary. Certainly a smoother collective stick application sees no such movement, and should hold well in 3D moves. I reduced the stop gains and rid the angry sound. I believe the remaing buzz sound is simply blade noise. It's very steady in a hover. I had to reduce the Common gain to 47 so far to fly a 2100 headspeed. Sorry for lengthy writing, thanks kindly for the advice.

[rcflyerheli]

I was having a problem with a mild tail kick on hard collective punches (maybe 10-15 degrees) I tried playing with the I gain values and collective precomp, at no avail. I changed my tail blades to CY 110s and that helped, but did not eliminate the problem.

I started playing with bank switching the other night, and kicked my overall gain values way up to see what effect it would have on the tail. Well I am happy to say that the gain value (for me this was 95) really did fix the tail kick in hard collective.

I feel that my tail setup mechanically is perfect with no rough spots anywhere along the travel of the slider, and a Torque 9188 running things. I've been flying this V2 bird for a little over a year now, and the tail kick has been present from the get-go. The tail holds great in every other area of flight and doesn't have any wag, so I came to the conclusion that the blades just were too short. Maybe I should have gone directly to 115's, but the 110s give me more ground clearance and work in every other area.

I am really starting to love the bank switching feature on my Vbars. It is simple to setup on my DX8 right on the ELE D/R switch. Since I am an old (literally) pattern flyer from the 80's, the D/R switch is perfect. Actually I use the other side (AIL D/R) for throttle hold, and I don't have to reach way up on top of the TX to get to any switch. I realize that this departs from the norm, but I'm not normal anyway, as I fly Mode 1, so it works for me.

[Justin Pucci]

Thanks for sharing your tuning experience, rcflyerheli! I'm glad to hear that everything is working out for you.

Remember that head speed and tail gear ratio are important considerations in determining tail performance. If you're running lower head speeds, you will benefit significantly from larger blades and so will the V-Bar control loop.

It sounds like you went through the proper steps to make sure that your V-Bar tail is set up perfect for your flying style. Now go beat that thing up mode-1 style and enjoy!

Cheers,
-->Justin

[firemedic295]

Tail driving me nuts.HELP.
My tail wags very slowly right to left when when moving the pitch/throttler up or down.Very noticeable while hovering or coming from fast forward to hover.just a slight kick then slow wag.my setup .

Goblin 700
scorp 4525-520 ult
jive 120 v11
bls 255/256
rail blaeds
links moving freely no binding anywhere. heli flies great.all electronics working fine

yaw rate 120
gyro gain 60
rc dead band 5
acc 75
p gain 70
I gain 85
gain A 20
gain B 20

Torque precomp

collective 10
cyclic 3
zer0 col 0

Thanks guys.

[Justin Pucci]

Firemedic,

Change your P and I gains to 75 and 75, keep your precomps the same, and start increasing your common gain slider. A value of 60 is pretty low for a 90-sized machine...depending on your setup, you should be able to get up to between 80 and 110. If you need to vary your I gain again, change your collective and cyclic precomps by 3 and 2 points, respectively in the opposite direction (I gain increases, precomps decrease).

Good luck and let us know how it goes!

Cheers,
- Justin