I posted this in the Kit Building but didn't get much help. So I'm hoping the RCKen or Minnflyer will come to the rescue. I finished building the Top Flite Piper Arrow over 1 1/2 ago and I' just now putting in the radio. When I was trying to set up the flaps with the servos a couple of the pined hinges (Robart type) came loose. Because of the ends that came loose I am not able to pull the hinge out to get glue down in the hole. What is the next best way to secure the hinges in place with out destroying the flap. Thanks for any ideas you might have for me.

chopper

Chopper,
Boy, you sure came up with a doozey of a problem. I know Minn won't be online tonight as he's in Florida with very limited online. But let me see if I can come up with a solution. Let me ask one question before going forward. Is it all of the hinges for the flaps that are loose?? Or just some of them??

Ken

There are 3 hinges per flap. 1 is loose on the flap and 2 are loose on the fus side. I tried to pull the flap off all together but I afraid of breaking the wing or the flap. I hate to have to glue the flaps up.
Thanks for you help Ken.

chopper

If you can get the flaps off you'll be better off in the long run when it comes to repairs. Otherwise you're going to be hard pressed to work any repair. If you can't get the flap off so you can address the hinges that came out of the wing you are going to wind up cutting the skin of the wing so that you can get glue into the hinge point from behind. That's really going to be your option for the wing portion of repair.

Ken

My vote would be to use a fine saw and cut all the hinges of. Then put in new ones just off to the side of the old. Don't try to get any of the old hinges out other that the ones that are ready to fall out. If they are loose but don't want to come out easllly, a couple drops of thin CA will lock them down so they won't be a problem later. You will add a few grams of weight to the plane, but this will be the least invasive fix.

Don

Added:

you will end up with double the half moon cuts for hing clearance, one for the old hinge and one for the new. You could glue some balsa scraps and shape them to the wood line and patch in some covering. Or just leave the hinge pin area from the old hinge and make it look like double hinges.

Don

Would it do me any good to cut away the covering around the hinge and just put a little epoxy aroung the hinge?

chopper

Chopper man,
I must admit that when I answered last night I was really tired, I just got home from covering E-Fest in Champaign. But now that I think about this I agree with Campgems. The easiest way of fixing this might just be cutting the old hinges and rehinging the flaps.

Ken

Probably a dumb idea, could he drill a couple of small holes above and below the hinges and try to get some glue into the holesabove the hinges?

It is probably better to cut off and restart but that might work.

If I remember correctly their are blocks in the wing and the flaps. I would hate to have to cut away the wing and the flap to install new blocks. I still have a few syringes from when my wife was so ill. so I think I will try to shot some CA into the flaps and wing with the needles. What are your thoughts?
Thanks

chopper

Do you know why these hinges came loose? My concern would be that something went wrong in your hinge installation, and that only a few have failed so far. You need to be sure you can trust the rest of them before you fly.

Good luck

I know exactly why. They call it pilot error. When I was trying to set up the flaps the servo moved a little to much and keep binding the flaps and of course I wasn't smart enough to reset the servo arm before trying it again and again [>:] Oh well live and learn.

chopper

Chopper man
I just experienced the same problem. While pulling on the flap, one of the hinge points came loose. I guess I did not get enough glue into the hole I drilled. What I am going to try is on the flap, cut a small notch on the bottom side of the flap to expose the hinge point, fill that area with 60 minute epoxy, let it cure overnight. Then spackle the area to get it smooth, then use trim coat to cover the area where the notch was cut. The rest of the hinge points are good.
You can print out an instruction sheet from Robart on hinge point installation. In step 4 of their instructions, it says in BOLD print,
"Warning: do not use CA glue to when installing Robart Hinge Points this will make the hinge brittle."

A little diversion here.. directed at the 'overtravel' for the servo possibly pulling the hinges out (if I got that right..). A voltwatch would tell you if you have a bind real quickly, and you can search for the source before the hinges get pulled out, then fix it right away.

No, not an advertisement for voltwatch, but one of the many obvious uses for this fine product.

CGr.

Thanks for the CA tip. I think I'll go with the cut out trick. It wasn't a servo malfuntional as much as it was me not putting the servo arm on in the correct position on the servo. I have some Zap hinge glue if it's still good after a couple of years. I wonder if that would go through a needle. I'm just a fraid if I start cutting I'll make a bigger mess then when I started.

chopper

I just tried using the needle. The needle I had is pretty small but the Zap hinge glue went through it with no problem. The one problem is that there is really nowhere for the glue to go as my hinges are a pretty tight fit. We will see, I think I was able to get some down in the hinge. I'll let it dry overnight and take a look in the morning. Just got to keep my figures crossed.

chopper

Could you also "pin" it in with a little pin drilled thru the hing? I don't know if there would be anything in the wing to help hold it tho.

Good luck

Jon

I can't tell you how close I am to just putting epoxy on the hinge to keep the flaps from operating altogether. The glue trick seems to have worked for now, but no matter what I do in adjusting the flaps with the servos they just will not quick chattering[>:] I adjust the endpoint adjustment and then it's fine and put the flaps the other way and it chatters. Fix that and put them back and they chatter that way again. What am I doing wrong?? I haven't built anything since this and I still look forward to building more but now I understand why we have ARF's.

Thanks

chopper

Try this:

When the servo is chattering, tap the flap lightly in both directions. If the chattering stops, don't worry about it - the vibrations of the engine will do the same as your tapping did.

It's not to late to cut the hinges off and install new ones.

You say the servo is chattering?? If you disconect the pushrod, does the flap move without binding? Does it move feely in its full range of movement?

Have you checked the servos for damage? IE chipped gear.

From the sounds, you may have to much movement on the servo. The fact that you can adjust the end point where it stops chattering but chatters on the other end of the travel would say that your end points are not adjusted right. Thes may be a dumb question, but I'll ask anyway. Did you adjust both end points or only one?

By the way, epoxing the hinges won't do much for you. If you want to disable the flaps, pull the servo and put in a lug that the push rod will tie to and mechanically adjust the flap to lock in the up position.

Don

They are brand new Futaba 3004 servos. No stupid questions as far as I'm concern. I did adjust both end of the EPA. The flaps move freely without the servos connected. I'm goijng back upstairs to work on the other servo installation. Hopefully that will go easier. Thanks for the help. Minn I'll try the tapping thing as well. Thanks

chopper