Servos DS520 tail servo ball link setup

[murankar]

Ok, I was reading the manual for the JR G270 3D gyro and a question formulated in my head.

Issue: My tail is still jumping around even with the gain set at 51 on my GA250 gyro. So the questions are
1) What is the proper location for the linkage ball on the servo arm for the DS520 tail servo?

2) Can that location affect how the gyro acts while in operation?

According to the JR Manual and their gyro they claim that if the linkage ball is to far out it will be necessary to reduce the gain or if the linkage ball is to far in it will be necessary to increase the gain.

Does this hold true for all gyros or just the JR G270 3D?

 

[Lee]

Yes. The further away from the centre, the more movement the servo creates causing greater effect on the tail with a given Gain and vice versa for ball being closer.

 

[murankar]

Since I still have some wag in the tail and gain so low. Should I go ahead and move the ball in one hole and see if I am able to eliminate the wag?

 

[Lee]

If you have set the ball in the recommended position, i would check everything else first. Check for binding in the tail linkage system.

 

[murankar]

In the Align 450 pro manual I could net find the setup info for the servo arm I am using. I am using the single arm one with 5 holes in it. I used originally the third hole from center. The manual is referencing the DS5A arm which has four arms and two holes in each arm. They show the linkage ball being located at the inner most hole. I see no measurements for the location.

I do however have a four arm servo arm. It has four holes in each arm not two like illustrated in the manual.

Thanks for the help

 

[Tony]

It should give you a measurement of how far out the ball is supposed to go from center.

 

[murankar]

There are measurements but nothing indicating the distance from center. Let me see If I can fond something on the interwebz for this.

I think I found something not sure. Does 8.18mm sound right?

 

[murankar]

I still was not able to find info as of yet. I did however move the ball link one hole in, which is the second hole from center. I was able to get the HH gain pushed up to about 54 and still had some small amounts of wag. I went through three batteries playing around with it and think that I could move it in to the last hole.

After moving the servo horn I went through the gyro set up to redo the end points. Id did feel more solid than the last flight. In the afternoon I will redo the endpoints once again for the new ball link location. I am thinking that the tail should start to lock up at this point. If not I do have two horns that are real close to the 8.18mm measurement I found in the manual. I am still not sure if that is the right number.

 

[Morelight]

I finally got a measurement for you from my 450 Pro V2 manual Matthias. My kit used the D5BF tail servo horn, which has 2 holes each of the 4 arms. You are supposed to use the inside hole to mount the ball link, and on page 19 of my manual, at the bottom left it shows the measurement :

10mm from center of the servo to the center of the ball link.

hope this works out on your bird.

 

[murankar]

I think I have the pro V1 manual from Horizon Hobbies. In that manual the tail servo install is on page 16. Mine is listing the DS5A horn. It sounds like they are almost the same design. My manual is also showing the ball going in the 1st hole of the D5 leg. My DS520 came with 4 horns and I used the one with only one leg on it. Without taking off the servo it appears that is where my ball link is right now. So I will go through and attempt to fly in the AM to see if it worked. It also appears that the horn with 6 legs might work for it also. Just did a quick recheck yes it is real close off by maybe a half mil. I will report my findings in the Early Afternoon. Thanks for the info!