built my ultra stick lite and used radio south blue 1/4 scale ca hinges . and now i want to use a zenoah g 26 . is this ok. could i use robart hinges were the ca hinges were if i have to cut them . [][:'(][:'(][:'(][:'(]

I had CA hinges in my Pitts with a DA-50. I cut the cut hinges out and replaced with Kletts Flexpoint hinges after two in the rudder failed after four flights. Kletts are similar to Robart Pinned hinges, but not exactly the same. The point being that yes, you can cut away the CA hinges and replaces with pinned hinges.

As for the Blue New South hinges, I don't use in anything larger than a 60 sized airplane and never with a gas engine. I honestly feel that the added vibration from a gasser will cause CA hinges to fail in time. The G-26 seems like a very nice smooth running engine. Since your plane is already built and apparently flying why not just keep the hinges you have in place and keep a close eye on them to see if you develop any problems. Thats what I would do if me.

Like the previous, leave them until they show signs of failure, then replace with a real hinge. Won't the G-26 be just a mite large for that plane?

I had a DP extra with CA hinges, I put a 50cc on it and left the hinges, they will be fine, keep an eye on them

The construction of the Ultra Stick does not lend itself to Robart hinges, the TE of the wings/stabs and the leading edges of the control surfaces are not thick enough. I used the CA hinges, just plan to give them a good inspection regularly.

My $.02 ... I have a 1/4 Giles 202 with an ST2300 and I used CA hinges per the manual... After about 10 flights I was retuning the engine when I switched from break-in fuel and one of the ailerons and the rudder started to rip off do to vibration... I am going to put all new CA hinges tommorow as I have been out of the country since it happened.. This time I am going to double the quantity.. If I had "real" hinges lying around I would switch to them though.. I am not real familiar with the Ultrastick 120 but if possible I would use "real" hinges.. If you have to use CA's I would double up on them at least at the inboard and outboard edge othe surface... Here is what I plan to do to my Giles:

My take on the subject is this. Dubro or Sig flat-bladed nylon pinned hinges fit nicely into the slot left behind by removing CA hinges. They are not prone to occaisional failure and glue every bit as positively as CA hinges. I no longer use CA hinges on anything larger than a .40 size airplane due to the fact that I have had a CA hinge crack everytime I did use them. If you are going to cut the controls away, then use the flat nylon pinned hinges. If you remount new CA hinges then sometime in the future, maybe in a few flights, maybe in 100, you will get to do it all over again.

As far as doubling up on CA hinges, you are also increasing the workload of the servo.


Mark

Oh I understand about the workload thing but I have 128oz servos, and the surfaces on my Giles when hinged as per the manual moved very easily...

Back to the original post, and I can't answer this, but will Gasoline attack Cyano period? Just another Q I thought of...

I've had no trouble from quality ca hinges on gas birds. It also helps if you seal the gaps. Tends to spread out the stress. The only time I've had a CA hinge fail is when I've over stressed it(crashed![&o]). For the moment, fly it and check on your preflights. Replace if and when they fail.

Kletts Flex Points are perfect when you have thin wood to work with. I used these on my Pitts and added two additional to each movable surface for a total of five hinges on each surface. So far I have been very pleased with these. A friend has used them for years in pattern airplanes, some of which are several years old with over a 1000 flights or more with zero failures.

All it took was one landing with an aileron missing on his gasser and one of my flying buddies replaced those ticking time bombs with real hinges. I think he used the Robart large scale hinge points.

I have CA hinges on my Ultra Stick Lite. Hundreds of flights and no problems. Its powered by a G26, by the way. Perfect combo. My GP Christen Eagle, on the other hand, started breaking CA hinges after 3 flights.. I replaced them all with Robart Hinge Points. No more problems. I had CA hinges on my GP Giles too. Worked great. Finally sold the plane after a couple of years hard use. Hinges are still holding up.

Well I have bit the Robart hinge bullet. I had a dead-stick on my Pitts yesterday as a result of the fuel tubing making contact with the muffler. Melted right through and then I discovered an air leak in the fuel valve as well. I guess the vibration with the fuel valve mounted in the cowling caused too much vibration and the seal failed. It was a new valve so I honestly doubt it was the results of debris in the valve, but could have been. Anyway, I am replacing with a fuel dot so that can't be an issue any longer. I know, you guys told me so.........

The DS landing was in the field and caught a clump of grass so the plane flipped over and broke the rudder off. It crumpled the rudder at the tip, but was easy to repair. No other damage thankfully. I decided to replace the Kletts flex points with Robarts simply because in drilling out the flex points the hole would have been too large to reinstall flexpoints. I drilled out the old hinges, recovered the rudder in the broken area and along the hinge lines for a clean finish. All ready to install. Going to use Gorilla glue after I finish my test on a spare rudder I had laying around. I want to make sure I know how much Gorilla glue to use since this stuff foams and expands on contact with water. This will be my first time using the stuff, but from all I have read this stuff is the ticket. If anyone has any final pointers before I use this glue please advise. I am going to wait a few hours to let the glue set up in the test.

In the picture below I show an example of the Robart hinge used and the flexpoint next to it.

I would use the CA hinges. I have CA hinges on my 28% Laser 200 with Brison 3.2 gas engine. No problems thus far. I like to use Pacer Hinge Glue on larger models. It doesn't crytallize and stays for flexible than CA. Good luck!

I agree with this post. I also seal the gaps both top and bottom and believe this adds strength to the hinge joint. I also have never had one fail from flight loads. Here is my last crash and the CA hinges didn't even fail in this. Notice all the controll surfaces.

Oh Patty are you OK? What happened?

Knife edge figure 8, looowwww, while talking to the guy next to me. Dumb!

Here is an interesting observation. Every time I find a topic on RCU about a controversial topic with multiple opinions I find this result. There are always those who use things for years without failure.

Examples - stock fuel tanks, PPM Rx in gassers, CA hinges in gassers, Plastic spinners on gasssers and glow engines, Fuel valves on gassers. Mods such as pinning and fiberglassing the firewall mounting box when using gas engines.

For me, this is what I experienced within the last five years. Stock tanks failed twice and now I don't use anything but a Dubro, Sullivan or Hayes tank and have never had a failure since. CA hinges failed on my Pitts and now I use Kletts Flexpoints or most recently Robart hinge points. Too early to tell how well these will work, but they sure seem to make sense if you look closely at the design vs CA hinges, and I have never read where someone had a failure using them. Fuel valve on my DA-50 developed an air leak - think the seal failed due to vibration. Now using a fuel dot so this won't happen again. I have never used PPM Rx on a gasser because I just didn't want to have to learn this lesson the hard way. I used a PCM after testing with PPM and making sure there was no interference. I also didn't have to learn the lesson about plastic spinners or having firewalls come lose because I did the proper things to ensure that I wouldn't have a problem in these areas, so maybe I'm ahead of the game on these issue.

To each his own I guess, but it amazes me how many times I hear about people using products with known failure experiences and then they change after they experience a failure of a product. I know I've done it. We all have to learn at our own pace I guess. I know nothing is ever 100%, but some things sure make more sense than others.

RFW1953, I agree with almost all you say. It was well stated. I would also say, though, that i have seen many things fail that shouldn't have: engines, airframes, recievers(pulled the antena out of one), gear, hinges, pushrods, you name it, not because of any defect but simply because they were missused, missinstalled, missassembled, or just abused. Some products(and the manufactures selections of them) get a bad wrap unfairly sometimes, in my opinion. If a guy just dosen't want to take the time to seal the gaps on his quarter scale, then he probably shouldn't use CA hinges. I just think people should know these things. There"s got to be a reason why some things fail for some but not for others and it would seam to point to the installation process. If someone is having problems with something and i'm not, i like to share my methods in the hopes it helps someone BEFORE something happens, that's all. And by the way, over the years, i have seen every kind of hinge know to this hobby fail in the air, at one time or another, and it was always due to poor installation or assembly.

ram3500-RCU -Points very well taken, and likewise very well stated. In fact I agree with your comments about poor installation many times being the culprit. I had a student pilot show up with a new trainer that required installing the CA hinges in the assembly process. He applied CA to the hinges and then inserted them into the slots. I had to laugh picturing how he kept his fingers from sticking together. [8D] Nearly all of the hinges came loose when I checked the movable surfaces during the preflight. Good thing we didn't take to the air, or this could have resulted in one of those "bad wraps" you mentioned about a products.

There are many reasons for good and bad product failures. Nothing is fool proof. By the way, sorry to hear about your PW. I always hate it when one goes in. On my first Pitts and first gas project I too used CA hinges as I had done on all of my airplanes before. I had a very bad crash and lost the plane and the engine. However, the CA hinges all remained intact just as yours did. Heck, my firewall didn't budge though I experienced a bent shaft in the engine, among other things. Maybe I would have been better off not securing the mounting box so securely. []

On my next Pitts project I installed CA hinges the same way I have always done and these failed on the rudder without any damage to the airplane after four flights. It was still cold so I think the temperature made them brittle and vibration got to them. Nearly all of them tore free very easily. Thats when I decided to make the switch. Now that I have installed the Robart hinge points we will have to see how this works.

Anyway, thanks for the response and the feedback. Good luck on your next plane. Have you picked one out yet?

rfw1953(wish i knew how to make it bold like you did), we all want the same thing, i think, just to help others avoid our mistakes, don't you think. About the plane, i have already replaced patty 1 with patty 2. I rarely do that. That's how much i think of that plane and she is such a good flyer. But, i'm also working on outfitting my new Carden 35% cap(3W 100 for power), and dealing for an RTF 30% Edge with a 3W 75. I would like to build one of those GP Christian Eagles but don't know if it will happen this summer. How about you?

Gary, In the spirit of helping others, making bold print is pretty easy. Hold down the left button on the mouse over the print you want to make bold and slide the mouse back over the print being careful not to go too far. Then in the upper left hand side of message box screen, below all the smiley faces you will see a small box with a B in upper case. Click on this and your print will be in bold. There are several other options such as Italics, underlining, and color print option as well.

The PW has been a big success for G.P. and I can certainly see why you would want another one. I had looked at this model, but opted for the W.M. Giant Extra 300S. This airframe could easily support a 50cc engine. I purchased a DA-50 and chose to put it in the Pitts and couldn't justify buying another one for the Extra at the time so I used an OS 160 FX. Being totally honest, I am very pleased with this engine in the Extra. It flies the plane very well, though this is not a 3-D machine with this power source.

The Pitts and the Eagle are similar, though I happen to like the Pitts covering a bit more than the Eagle. Just a personal preference. As for new projects, I have been thinking about the G.P. Stearman, which looks like a really nice BIPE. I have followed the thread where guys are putting the Zenoah 26 on the nose and seem to be pleased. As for larger planes, I think the Pitts is about as large as I want to go at this time. I have stuck with 1/4 scale and the Pitts is the only 33% model I have in the hanger. Based on my skills the Pitts is a handful on the ground, but once in the air it's a baby. [8D]

Good luck with your new project and thanks for the healthy exchange of opinions and ideas on this thread. Sometimes people get into flaming with harsh foolishness and reading way too much into responses, which easily happens with the written word.

On the Eagle / Pitts comparison... From What I understand Christensen took a Pitts frame and made mods to it to correct some of the Pitts bad habits.. Does this reflect in the Models to your knowledge? Or is it 6 in one, 1/2 dozen in the other?

Hi Scott........ Hm..........Difficult question to answer. I would have need both planes side by side and then fly them to provide an accurate answer. Here is what I understand from my perspective. Keep in mid I know much more about the Pitts than I do the Eagle.

I think your latter comment is probably more accurate. Meaning, they basically took the same airframe and changed the covering. However, the Eagle fuse is a bit longer, which may help with the ground looping tendency on the Pitts. The cabbane and interplane struts are the same. G.P. sent out new cabbane and IP- strut brackets at no charge to Pitts owners who requested them. I think this is standard with the Eagle. In the earlier Pitts model these had a tendency to break, but all kits now come with the upgrade. The cowling on the Eagle comes with a cowling ring which is an improvement. I think they beefed up the mounting box and the firewall on the Eagle to be more accommodating for gassers, though on the Pitts this is easily resolved with pinning, tirstock and fiberglassing. Like I said, when I lost Pitts-I, including the engine, the firewall remained intact. Also, the newer model Pitts now have better ply on the mounting box firewall, which may be what they are now using on the Eagle. Regardless, I still reinforced mine just to be sure.

As for flying, from what I have read on the Eagle and experienced on the Pitts, I think they are pretty similar. Both are easy once in the air, but can be a handful on the ground. Rudder and throttle application are important on both. Landing requires power to the ground.

Maybe someone else can provide more info on this though this is off the topic for the original thread. There are several good threads on the Eagle for those interested. Here is one.
http://www.rcuniverse.com/forum/GP_C...1176170/tm.htm

Hay, check this out.Now we're all in trouble. See what you've doneOn the Eagle, i saw on Discovery that Christensen did start off buying a Pitts frame but decided not to use it and it is still hanging in his shop never having been finished. He started from scratch with the eagle, although retaining some of the same feachers. Don't know about the Great Planes version though. I would guess they're not as differant as the real ones are.

I am considering the Stearman as well but i don't think it would be as aerobatic as the Pitts or Eagle and i'm just in that mood right now. Miles Reed stopped by are field Monday with his 40% Weeks Solution. What a gorgious airplane! I got jellous. He is in his 80s and still builds with the best and flys what he builds. His classic take off( a snap as it breaks ground) is still part of his routine.

By the way, he doesn't use CA hinges. Had to throw that in for the topic.