Sloppy hinges onth 2.6m comp-arf

[FastnLow]

I have one solid season on my 2.6m comp-arf extra and I'm amazed how poor the hinges (phenolic) on the tail have held up. There all worn out, anyone else encounter this? I fly it with 8611A,s on all control surfaces set up rock solid with no slop on day one. By flights 100-125 the phenolics are shot and picked up some small amounts of flutter before I grounded her for the season. After it was down I checked everything on the servos and linkages and found nothing wrong, the phenolics are the weak link in the chain or it's that sad excuse of a hinge rod they supply with the kit, too small maybe? HELP!

[Andy540T]

I have used thick ca on the phenolics in the past to tighten them up. Put a light coat of wd40 on the rod and then slide it inplace. The ca won't stick to the metal but will fill the gap in the hinge.

[Biff]

I would check the wire that goes through the phenolic, it's pretty hard stuff. We've seen some wear on the Youth Masters planes. Traced the issue to wear on the wire and a bit on phenolic. Easy fix! Get new wire to slide through the hinges slightly larger than what you now have. Fastest fix is a touch of thick CA applied to phenolic and wiggle the elevators to keep from gluing them down.

I don't view this as a quality issue. It's a wear issue. Phenolic is pretty hard stuff, so is the wire that slides through the hinge points. Something has to give. This is a bushing not a true bearing, it will wear. We had a touch of flutter and went through the process you're going through now. It's an easy fix and works very well. No more issues after we addressed the problem.

The elevators are removable, therefore the fix is simple. The rudder is the same thing. You didn't say if your trouble is in the elevators or the rudder. Either way the fix is the same. Had you said the ailerons are giving you trouble, that would have been a quality/design issue that would have been a bear to repair.

I feel you dude. Anytime you ground and expensive airplane for flutter, there is nothing but frustration. I've flown the Comp Afr planes and have come to understand Andreas's technology. It's SO different from wood/foam/ply airplanes that there's a learning curve involved in the care and feeding of them. I'm not doing damage control for Comp ARF, just saying those flying them need to take a step back and approach maintenance a bit differently than other airframes.

Hope this helps dude. Honestly the fix took us about as long as it took to to write this response! We did it between rounds at the Matt Chapman Youth Masters! (And I type with two fingers) Give it a shot and let us know how it goes. Since our fix,there is no slop in the set up what so ever. After another year of flying expect to repeat process if needed.

[Reza]

Biff,

Great stuff man. As a matter of fact my comp-arf 2.3 elevators vibrate as hell when the surfaces are in neutral but I honestly thought it was normall. Thanks to you guys, now I know I have a problem to take care of. So basically I need to take the elevator off and apply some thick CA to phenolic hinges. Great, I will take care of this before next Saturday. You know I have tuned pipe and the engine is really quite but the plane was noisy because of all those excessive vibrations that I'm going to fix. Thanks again.

[Biff]

Reza, take the elevators and rudder off. Slide the rod into the phenolic hinges. Put some thick CA on the phenolics one at a time and keep twisting the rod as you do. All the sound you hear from the plane will stop instantly and there will be zero slop on your surfaces. Works like a champ!!

[Reza]

Biff,

will any CA stick to the rod? How about I do this with a round toothpic so I don't get any glue on the rod or actually I have to do it with the rod so I don't mess up the tolerance? Thanks Biff.

[Biff]

Reza, there will be a touch of CA that sticks to the rod. But it's like CA that sticks to glass,comes right off. You just don't want to glue the rod to the phenolic. That would be an issue! It's scarier sounding than doing. Start with the outer most hinge. You'll get a feel for it. After you do one you can pull the pin and exacto the CA off. It's really not an issue.

[Nobody]

We have the 2.3 Comp Arf and it is an awesome airplane to fly. My son loves to 3D with it as it is excellent for this. I just wish CA would do something different in the way they hook up the control surfaces to the servos. Its reminds me of a glow plane. We are adding extra arms to each surface so we can use ball joints with pro links. It seems kinda cheap on such a nice aircraft. We have had trouble with the arms wearing and causing some flutter as well. It is somewhat of an easy fix but would be nice if it would come factory this way. Its an awesome plane, though!

Tom

[FastnLow]

Thanks for the hints guys much appreciated, will let you know the results of the repairs Cheers!

[Dennis C]

Get a hold of darcy wingo his got a mod that he does and im sure he'll tell you guys how to do the repair the correct way. just send him a p.m.

[Reza]

Biff,

I did take out the elevator tonight to do the fix per your instruction. The only problem that I faced is two guides fell from one half elevator! They're hard plastic. Did I damage anything or will that cause any problems? Thanks

[PTS]

Get in touch with Andy Kane (Comp ARF). He sells a bearing insert and stainless rod package to stop the problem. Snap-in & Insert!!!

Perry

[Reza]

I did call Andy and there is no bearing inserts for 2.3 He says I have to cut the elevator and glue these guides back in. Damn anything I touch on this plane seems to cause another problem. I don't even know which hinge slots are missing these guides. Maybe I should just sell the plane. This plane has been too much trouble from day 1.

[Reza]

Another problem with Com-Arf is their customer service. These guides are not supposed to come off. That's what I was told by Bob Shapiro but yet they don't offer replacement to support their products. They're saying it is not meant to be repairable item, so why not offering replacement. Honestly this is my last comp-arf.

[Biff]

Reza, are you saying the phenolic "hinge" came out of the stab? I'm a bit confused. Sorry dude. Need a touch more info.