Beam's tail bouncing problem

[ZongHans]

I'm currently flying the Beam E4. Using JR770 gyro with the inolab tail servo. The servo speed is 0.07, 2.4kg torgue. Servo speed option on the gyro is set at high.

When I do hard stopping on the rudder, it kindda bounces around (left right motion) for about 4 times before stopping. The bounce is super high speed. I tried reducing the gain, but it still bounces....only at a slower rate. My headspeed last tagged was at 3100RPM. All blades are stock.

Wonder if this action by the heli is normal? Or is there anything wrong with my Futaba 6EX 2.4GHz settings? D/R for rudder is at 80%... Anyone share your settings opinions?

[helirulz]

What is your gain setting?

If electronic gain is not sufficient, you can reduce mechanical gain by moving the ball on your rudder servo horn in towards the centre.

If you do so, don't forget to redo your travel limit.

[ZongHans]

What is your gain setting?

If electronic gain is not sufficient, you can reduce mechanical gain by moving the ball on your rudder servo horn in towards the centre.

If you do so, don't forget to redo your travel limit.

My gain is set to the maximum allowable that will not result in tail wagging. For my controller is about 9%. But some people said this is a normal reaction when you E-stop the rudder.

[HotDogBun]

Let me share with you what are the rough values I set on my DX7 for my 2 JRG770T gyros.
- EPA (end points) = 150% for left and right, maximum
- 63% for headlock and 20% for rate mode. For DX7, the head lock is off at 50%.
- Dualrate = 50%. Increase value and piro will be faster.
- Expo = 0%

My heli holds rock solid. Tail slide and tail holds rock solid.

[helirulz]

My gain is set to the maximum allowable that will not result in tail wagging. For my controller is about 9%. But some people said this is a normal reaction when you E-stop the rudder.

The fault lies in your setup then. You setup your gyro gain by trying to obtain as much gain as possible without the heli's tail wagging in a hover.

You have to reduce the gain till it stops wagging throughout the flight..irregardless of what maneuver you are doing.

You did mention that reducing the gyro gain slowed down the wagging tendency. Why not reduce it even further?

If reducing it all the way still doesn't solve the wagging problem, move the ball on the servo horn in as i mentioned previously.

[Lplate]

Let me share with you what are the rough values I set on my DX7 for my 2 JRG770T gyros.
- EPA (end points) = 150% for left and right, maximum
- 63% for headlock and 20% for rate mode. For DX7, the head lock is off at 50%.
- Dualrate = 50%. Increase value and piro will be faster.
- Expo = 0%

My heli holds rock solid. Tail slide and tail holds rock solid.

Wonder if I can use the same settings for my Spektrum DX6i and GY401 gyro with 9257 on Mini Titan? Afraid to practise reverse flight for fear of not having properly set-up tail.

[ZongHans]

Let me share with you what are the rough values I set on my DX7 for my 2 JRG770T gyros.
- EPA (end points) = 150% for left and right, maximum
- 63% for headlock and 20% for rate mode. For DX7, the head lock is off at 50%.
- Dualrate = 50%. Increase value and piro will be faster.
- Expo = 0%

My heli holds rock solid. Tail slide and tail holds rock solid.

Hmm....you did mention yours is a DX7... Well, I did mine on my Futaba 6EX 2.4GHz. But my EPA is max at 140% left and right, 10% headlock and 70% D/R expo at 0%. My Gyro gain is positive headlock, negative non-headlock mode, 0-100% on both sides.

I even shortened the servo horn. But the end result is only reduced bounce. Now maybe about 10 degree bounce compared to previous 90 degree bounce. This was done based on a full round of pyro. Maybe at a speed of 1.5 rounds per second.

Also, could it be due to the problem that I'm using a non-JR controller? Anyone out there with futaba controller encounter this problem?

[ZongHans]

Great news! I finally solved the mistry! The tail bouncing problem did not only occured to me, but some other people and their heli as well! The verdict, JR770 is a super sensitive Gyro that is unforgiving to the slightest vibration!

On my last flight day, after consulting some of my great flight buddies, they noticed that I had a Gyro strap attached to my Beam. I did the strap thing because the Beam's Gyro mounting surface is poorly designed and becomes loose as time goes by. To stop the Gyro from shaking around, I used the strap since the maiden flight of my beam. This strap, is the main cause of the tail bouncing problem.

Continued tests to the problem revealed that the bounce only occured on the clockwise pyro direction... I even consulted some of the JR770 supporters. But I finally came to a website's review of the Gyro. The site mentioned that initial tests showed that the JR770 is a crappy Gyro! But after some fine tunings to reduce the heli's vibrations, improvements were noticable! Oh, by the way, they did the test on a nitro heli which had a rough engine and did flew well using a Futaba 401 Gyro. After smoothening out the engine and some mega Gyro dampening, the JR770 held the heli even better then the 401!

Their conclusion? JR770 is hell of a difficult-to-set-up Gyro but with the proper method of setting it up, its a great Gyro! Value for money too, if you considered the 611.

My solution to my heli? Apply some epoxy to the contact points of the Gyro mounting surface to the main frame. Then, use 3 layers of foam tape....The kind with black foam and dark green insulation film. Stick the Gyro in, and then increase the gain. Mine now has a 14% gain as compared to the 9% gain with no tail wagging even during side flight and punch ups.

[ZongHans]

Great news! I finally solved the mystery! The tail bouncing problem did not only occured to me, but some other people and their heli as well! The verdict, JR770 is a super sensitive Gyro that is unforgiving to the slightest vibration!

On my last flight day, after consulting some of my great flight buddies, they noticed that I had a Gyro strap attached to my Beam. I did the strap thing because the Beam's Gyro mounting surface is poorly designed and becomes loose as time goes by. To stop the Gyro from shaking around, I used the strap since the maiden flight of my beam. This strap, is the main cause of the tail bouncing problem.

Continued tests to the problem revealed that the bounce only occured on the clockwise pyro direction... I even consulted some of the JR770 supporters. But I finally came to a website's review of the Gyro. The site mentioned that initial tests showed that the JR770 is a crappy Gyro! But after some fine tunings to reduce the heli's vibrations, improvements were noticable! Oh, by the way, they did the test on a nitro heli which had a rough engine and did flew well using a Futaba 401 Gyro. After smoothening out the engine and some mega Gyro dampening, the JR770 held the heli even better then the 401!

Their conclusion? JR770 is hell of a difficult-to-set-up Gyro but with the proper method of setting it up, its a great Gyro! Value for money too, if you considered the 611.

My solution to my heli? Apply some epoxy to the contact points of the Gyro mounting surface to the main frame. Then, use 3 layers of foam tape....The kind with black foam and dark green insulation film. Stick the Gyro in, and then increase the gain. Mine now has a 14% gain as compared to the 9% gain with no tail wagging even during side flight and punch ups.

By the way, the revied website is here.

[Ice93]

Glad to see you solved the your problem...

[perfect1]

Currently I am using a piece of rubber band to hold the gyro. No issue so far.

[Ice93]

Here's a pretty good guide for the JR770

http://www.helifreak.com/showthread.php?t=78591