Servo control rod length ??

[dave26985]

Hey freinds,
I am building my new H550. I have been using finless' awsome build vids, and the many other great posts from all of you on this site. Many thanks !!
Their have been some minor differences in my build so far because of Bob's stock plastic frame & my CF one... so far overcome.
However I was just assembeling my first servo rods which are the 2 that go from the elevator control lever to the elv. servo. In the manual it looks like they are measuring the length from the inside most part of each link. in order to take care of the stock links being to short I made replacements with one end using the raptor link, but using the length from ball to ball, of the assembled stock one.
When I put it up to my control lever & servo it was way to long. In fact I had to go back to the stock links in order to screw them on far enough to get the proper length. What the heck am I doing wrong ??
I am using the Gaui CNC elev. lever, & maxwell 821's,(same size as DS821)
The measurment from ball to ball is 67mm. Any idea's ?? Also can someone give me their measurment from ball to ball from elevator lever ball to servo horn ball.. Thanks.
Dave.

[ptang92]

I think the balls and measurements will vary depending on which H550 and servo you have. I realized this during my build when I replaced the plastic elevator lever with the CNC. I tried using the Raptor 30 links and found that it would have been too long with 2 Raptor 30 links. I used 1 Gaui and 1 Raptor link for all of my servo connections as that gave me the right length linkage while giving the links enough threads without worrys.

So I think your setup will vary depending also on the servos and how far their arm/wheel center is from the levers. Work with what is best for your configuration. I'm using 3004 servos as I had them handy. I actually converted 3003 as wanted a BB servo and it was the cheapest for me as I'm only a beginner...

[mjdee14]

Mine is 67 mm right on the button. And I also used the gaui link on the elevator horn...and an ECO8 link and ball on the servo.. Nice thing with the CNC elev crank is you don't have to do the offset on the servo wheel.

[dave26985]

Thanks ,
mjdee14, nice inset on your `cain over `cain pic. Yea the CNC lever makes it nice, also the CNC bellcranks do the same for the throtle & ail. servos. I just don't understand how, if we have the same 67mm distance ball to ball, that with the stock links you could have 44mm between the inside of the them.
I guess thats part of the reason that in this hobbie you have to be just the right mix of wanting to fly a chopper, and wanting to "build" a chopper. It is the perfict mix of challenge & fun!

[Pinecone]

In general, the link lengths in the manual are to get you in the ball park and to make sure you use the proper link in the proper location.

But EVERY link needs to be adjusted to what YOUR heli needs.