Comp-Arf 2.6M Extra 260 (Ailerons)

[rcheliman]

Guy's just wanted to see if there has been any other problems with running one servo per wing halfon the Comp-arf 2.6M Extra 260 of a rep at the Joe Nall show sold me one with everything set-up, thought I was getting a real deal, well you know how them real deals go. After four lumbering flights it was time to ring her out. Well after the first snap roll, in she went. After examination and others watching the flight it was discovered that the phenolic aileron control horn broke, all we could summarize was the twisting on the aileron broke it.The servo was a new JR 8711, Just as a heads up, be very careful running only one servo per wing on these airframes as they were designed for two ailerons per wing half. Oh yea the rep did say he was sorry for my loss.

[Howie]

What length arms did you have on the servo?

Did you have a clevis on the phenolic horn or a ball link?

[rcheliman]

Had 2" SWB arm's with Ball links on both ends.

[camss69]

If you had a ball link on the phenolic side of the linkage that was your problem, those arms will not tolerate any type of twisting, especially if you only had the one arm for the entire aileron.

The ailerons are very stiff, there are quite a few people running a single aileron servo per aileron.

Are you sure the guy was a rep from comp-arf? In the instructions included with that plane they state several times with emphasis NOT to use a ball link on the phenolic side. It would surprise me if you got one from a comp-arf rep and I would say he owes you a plane if you bought it that way from him and he didn't warn you.

[Howie]

	Quote: Originally Posted by rcheliman
	Had 2" SWB arm's with Ball links on both ends.

I too am sorry for your loss but there are two problems with your set-up.

1. You can use one servo but only with a maximum of a 1.5" arm on the servo. (Assuming you had a standard control horn on the aileron.)

2. You cannot use a ball link on the phenolic horn. The twisting force will allow the horn to flex and that will allow flutter to happen.

I have seen many of these set up with only one servo per aileron. No problems at all but they all have had only 1.5" or 1.25" arms.

[rcheliman]

He was a Comp-arf Rep even gave me his business card. He built the plane to sell, He told me it had one test flight on it. I did contact him via email direct and his response was he was sorry for my loss and that's it. All I'm saying is that you must be very careful with this set-up. I will never run this set-up again on any airframe, They were engineered to have two and all I'm saying is too use two servos to be safe.

[RTK]

I have been running 1 servo per wing on the 330 version with no problems so far. But as mentioned I used the stock clevis on the phenolic and a ball link on the servo arm. Going on 2+ years now. As long as you do not put a ball link on the phenolic you are fine. Nothing wrong with the stock set-up either, but I was using swb arms on some of the servos.
It's the plane in my avatar, nothing flies like a 22.5 lb comp arf.

[rcheliman]

Why don't they just use metal control horn like other companies and it would'nt be and issue. This was my 1st comp-arf it was a beautiful airplane,yellow Kiwi scheme.

[pepatrick]

I had a single 8711 on the aileron on my 2.6 Yak..The Yak ailerons are much larger than the 260...I never had any problems after nearly 80 flights (sold the plane). I used 1.5 SWB arms and the heavy duty clevises from Dubro...Unless you are using 2 control horns (not standard on 2.6 planes) ball links will twist the phenolic control horn can cause all sort of problems like crashes..The 3.0 meter planes have 2 control horns per servo..ball links work well in this configuration..I wish Compy would put dual horns on the 2.6 meter planes.

[rcheliman]

I'm with you brother, but I wish they would run two metal control arms and sandwich the ball link inbetween them. This would surely be a bullet proof method.

[pepatrick]

The phenolic is bullet proof if it is setup right..I had a 2.6 Extra 330 that had the Dubro arms..It worked well too...but it tore the composite material...I prefer the phenolic setup...but you have to know the limitations.

[cap 232g]

My compy 260 2.6 is working great with one 8711 per wing. I doubled up the phenolic horns and used a ball link in between. I am also using a 1.5 in SWB arm. One 8711 on the rudder is also plenty for any move you can throw at it. This plane with a DA-85 is the ticket.

[tmac48]

I use ball links on single horn. but with two links.

[rcheliman]

Now that's using your head.

[crhammond]

I have the 2.6m 260 and the hard point in the wing was not glued very well (factory) on the inside of one wing. The hard point broke free (phenolic still attached.) The phenolic was only glued to the wing skin at this point. If I had been running only one servo it would have been game over.

Luckily I noticed the problem (plane was not centering correctly.) I was able to cut away the skin slightly and re-glue the block (generous amounts of hysol.)

2 servos gives some added security against all kinds of potential failures on these planes IMO.