270 Fusion - Wobble Wobble

[The_Fox]

Well, good luck, i do not think the AR636 is defective. I have a few, and had some more of them. To me it looks more to be a defective servo.

[Psycho_dad]

Maiden flight of my 270 ARF went perfect ==> Not a single wobble, rock solid in all idle ups


Summary:
- AR636A is not the root cause of wobble wobble on my 270 BNF
- so issue in video must be mechanical related...

Conclusion:
I'll keep my 270 BNF for spare parts and keep flying my 270 ARF.

[brianbremer]

Based on the video that is definitely too high on the d-gain for the cyclic. This may require some adjustment depending on altitude density, desired head speed, servo performance (they all vary a little), on and on.

When using the advanced parameters (stick programming) don't be afraid to bring the d parameter down to 50 or less. The advanced parameter adjustments are scaled to safe adjustments so it takes a large adjustment to make a difference.

If your transmitter supports forward programming I would recommend using that instead, so much easier. Basically any tx running airware 2.01 or later and does not have "e" in the product name should support forward programing.

When using forward programming the gains are much closer to the actual gains so adjustments should be kept smaller (3% at a time).

If you do switch over to forward programming make sure you go back and set the stick programming advanced parameters back to 100 to avoid stacking adjustments.

Thanks and Best Regards,
Brian Bremer
Horizon Hobby, LLC

[The_Fox]

According to Brians post and to the fact you have used Emax ES08MD II cyclic servos, I guess the slow cyclic servos (at half the speed of a H3050) have solved the problem of to high gain.

[Psycho_dad]

Once again thank you all for your replies


@ Brian,

Thanks for your advice. My transmitter is a DX8E = no forwarded programming...

2 weeks ago, I did lower the D-gain from 90 to 60 (in steps of "5" a time) and testflown the heli after every change. It kept wobbling like hell and I did not notice the slightest improvement even at 60.

Maybe in the nearby future I will try to get my 270 BNF up flying again, but for now I'm happy that my 270 ARF is performing well. I really love this small powerhouse on steriods

grtz
PD

[Brick]

Psycho_dad, good to hear man ! I took my D gain down to 50, glad to say I am also wobble free

[brianbremer]

Please keep in mind if you are using the advanced gain parameters (stick programming) the adjustments are much less sensitive than the forward programming equivalents.


This was done for those that did not have the telemetry screen and had to use the swash plate angle to set the values.


If you are seeing a similar wobble and using stick programming, Cyclic D in the range of 10-60 would be normal.



Thanks and Best Regards,
Brian Bremer
Horizon Hobby, LLC

[Vrooooom]

I just replaced all 3 bearing blocks. After seeing roll while spooling down, I pulled the head to check for play. I noticed the top bearings where chattering. HH took care of this and I installed them. Of course the new ones are perfect, however the lower bearing was slightly crunchy, too. Again, HH sent me the lower also which I installed yesterday. While I was at it, I noticed a lot of play in around the ball joints. I remembered an old mod on the MCPX where grommets were placed in between the pushrods and balls to help with vibrations. A long story short, I used shrink tubing on each ball. It’s just the right size to slip over the joint, I left enough joint exposed to clip on the rod without binding. All of the play in the head is gone. Spooling up or down is now like my 360 cfx. Not a bit of wobble or roll. The head feels and sounds tight. All the tail wag is gone, also. Stock.

[Brick]

well I'm back to the vicious wobbles. This Heli is no fun to fly with the stock fbl. gonna bite the bullet and try another fbl . just too much problem chasing and adjusting......and NO flying

[Psycho_dad]

Sorry to hear that Brick. I know how frustrating it can be to keep searching for solutions and no flying.

Hope it works out for you because once this heli is up in the air (and running) it's

[ConductorJimmy]

Brick, did you figure out how to get rid of the wobble? I am having a lot of issues..

Originally Posted by Brick

well I'm back to the vicious wobbles. This Heli is no fun to fly with the stock fbl. gonna bite the bullet and try another fbl . just too much problem chasing and adjusting......and NO flying [IMG class=inlineimg]https://www.helifreak.com/images/smilies/thumbdown.gif[/IMG]

[Psycho_dad]

@Conductorjimmy,

can you describe your current tail wobble ==> fast / slow / does it occur in all idle-modes / …

My first 270 Fusion BNF had a tail wobble right out of the box; steps I took:
- lowered the gyro settings with several points
- changed the PID settings (advanced parameters)

Don't let this issue get you down, once it has been re-solved you will love this heli

[ConductorJimmy]

It has slow wobble going left and right. When I lower the D gain, it wobbles more. So I higher the D and it was when I raise it to around 130, the wobble became minimal. However, when I switch to idle 1 and idle 2, the whole heli started to shake like crazy...

Originally Posted by Psycho_dad

@Conductorjimmy,

can you describe your current tail wobble ==> fast / slow / does it occur in all idle-modes / …

My first 270 Fusion BNF had a tail wobble right out of the box; steps I took:
- lowered the gyro settings with several points
- changed the PID settings (advanced parameters)

Don't let this issue get you down, once it has been re-solved you will love this heli [IMG class=inlineimg]https://www.helifreak.com/images/smilies/headbang.gif[/IMG]

[The_Fox]

Set the D-Gain back to stock value. The Parameter You have to deal with first is P-Gain, becouse it`s the one wich is active first and all the time. A slow wag means, P-Gain is set to low. (Or gyro settins in Tx is to low.)
Set Gyro back to stock value first in Tx, 50 as far as i know, not shure about this.

Now start hovering in calm conditions. If a slow wag occures, increase P-Gain. If P-Gain is to high, it will oscillate.
You should increase P-Gain untill it is to high, and the tail starts oscillating, then decrease just a little bit.
D-Gain Parameter is the amount of "Blast" that will occure, when a strong wind will push the heli from a side. At that moment, the tail has to react suddenly, quick, and with the right ammount of power, to not overreact. That`s what D-Gain does.
When You have fixed the wag issue in hover by ajusting P-Gain, try a foward flight. If there should occure a wag in fast foward flight, increase I-Gain Parameter according to what You did to the P-Parameter.
For the ammount of D-Gain, Hover in windy coditions and hover the heli nose in to the wind, than turn sidewards to the wind. Now you can see the reaction of the D-Gain and adjust it.

After this procedure, there might occure a wag or oscillaion when changing headspeed. In this case, You can adjust by gyro gain from tx.

For better understanding, imagine this: P-Gain is the ammount of tolerance the FBL will show to a tail drift. If set to low, the FBL will allow some degrees tail drift to the right, then activate the servo to correct it leftwarts. (With the speed you set in D-Gain Parameter) So it will drift to the left, but to much, becouse the FBL is very tolerant. When it reached the end of tolerance, FBL again will correct it to the other side, and so on. By increasing the P-Gain, FBL will be less tolerant. Minimal tail drift will be corrected immediately, you will not even notice. When P-Gain is set to high, it will "over-correct". Thats when it will oscillate.
D-Gain will control the yaw speed while the correction occures. With P-Gain set up right, the tail usualy will not wag, so only minimal corrections will be needet. But if a strong wind should hit the heli from the side, or a high torque force should try to yaw it, the D-Gain parameter has to be set up to go in: "BAMM"! - tail corrected, but exactly to the point, no overrecation.

[ConductorJimmy]

Thanks for such detailed information! I will try it out this weekend. Pray for me!🙏

Originally Posted by The_Fox

Set the D-Gain back to stock value. The Parameter You have to deal with first is P-Gain, becouse it`s the one wich is active first and all the time. A slow wag means, P-Gain is set to low. (Or gyro settins in Tx is to low.)
Set Gyro back to stock value first in Tx, 50 as far as i know, not shure about this.

Now start hovering in calm conditions. If a slow wag occures, increase P-Gain. If P-Gain is to high, it will oscillate.
You should increase P-Gain untill it is to high, and the tail starts oscillating, then decrease just a little bit.
D-Gain Parameter is the amount of "Blast" that will occure, when a strong wind will push the heli from a side. At that moment, the tail has to react suddenly, quick, and with the right ammount of power, to not overreact. That`s what D-Gain does.
When You have fixed the wag issue in hover by ajusting P-Gain, try a foward flight. If there should occure a wag in fast foward flight, increase I-Gain Parameter according to what You did to the P-Parameter.
For the ammount of D-Gain, Hover in windy coditions and hover the heli nose in to the wind, than turn sidewards to the wind. Now you can see the reaction of the D-Gain and adjust it.

After this procedure, there might occure a wag or oscillaion when changing headspeed. In this case, You can adjust by gyro gain from tx.

For better understanding, imagine this: P-Gain is the ammount of tolerance the FBL will show to a tail drift. If set to low, the FBL will allow some degrees tail drift to the right, then activate the servo to correct it leftwarts. (With the speed you set in D-Gain Parameter) So it will drift to the left, but to much, becouse the FBL is very tolerant. When it reached the end of tolerance, FBL again will correct it to the other side, and so on. By increasing the P-Gain, FBL will be less tolerant. Minimal tail drift will be corrected immediately, you will not even notice. When P-Gain is set to high, it will "over-correct". Thats when it will oscillate.
D-Gain will control the yaw speed while the correction occures. With P-Gain set up right, the tail usualy will not wag, so only minimal corrections will be needet. But if a strong wind should hit the heli from the side, or a high torque force should try to yaw it, the D-Gain parameter has to be set up to go in: "BAMM"! - tail corrected, but exactly to the point, no overrecation.

[Brick]

Originally Posted by ConductorJimmy

Thanks for such detailed information! I will try it out this weekend. Pray for me!🙏

did you get it flying right ? I tried to get mine adjusted (again) today. I still have a bit of tail wag. and in IU modes I still get some shakes. the shakes are what worry me while flying, don't want to shake anything loose. I took my tail assembly apart and it all moves smooth and the tail rod is perfectly straight.

[ConductorJimmy]

I have not been able to flu for a week since my last crash that destroyed the main gear. The new main gear is on the way here, but the USPS is for some reason having an issue to delivery the package.... Still waiting...
Have you had any luck?

Originally Posted by Brick

did you get it flying right ? I tried to get mine adjusted (again) today. I still have a bit of tail wag. and in IU modes I still get some shakes. the shakes are what worry me while flying, don't want to shake anything loose. I took my tail assembly apart and it all moves smooth and the tail rod is perfectly straight.

[gyronut]

Jimmy, I am sorry that the USPS has been dragging their feet on that package I sent you last week. Considering I am only 2hrs away from E-ville.

[ConductorJimmy]

Richard,

I am sorry if my post came out in a wrong tone. I am truly grateful that you are so generously sending the main gear to me when you saw the main gear was in backorder in HH.

The post office is doing their best to make sure things happen and I am not saying this is anyone’s fault.

I reached out to the post office and they actually called me just an hour ago. At this point we are not sure where the package is and they are trying to see if they can find it.

Richard, thank you so much for being so kind and I will keep you posted when we find out about the package.

Jimmy

Originally Posted by gyronut

Jimmy, I am sorry that the USPS has been dragging their feet on that package I sent you last week. Considering I am only 2hrs away from E-ville.

[BrokeDad]

I see they are in stock again so I ordered a couple to have as spares.