Was flying my ultrastick for about the 100th or so time today and my inboard flap came off. It was severed clean, right along the hinge line. This is a bit perplexing. I used the stock inges that came with the kit and installed them as per the instructions - really there is only one way to do them too. No pull-outs - just a clean cut as if it were done with a new No 11 blade.

I'm running a 50SX and have the ailerons and flaps coupled so they do get a workout but not too much stress.

Big quesiton is - should I consider this an isolated instance or should I be looking to replace all 20 or so hinges? Any suggestions on how would I inspect the other surface?

I really tugged on the other surfaces - but I do that every first flight of the day...

Thanks for any ideas...

Yea, same thing happened to me and my US40, but the hinge severed on the ground.

Cause? Using too much CA and having it puddle at the hinge line creating sharp crystals that cut with every movement.

Instead of replacing all of the hinges I just sealed the hinge gap with clear 3M shipping tape and inspect the surfaces before and after each flight.

So far no other hinges have failed.....guess I just over-CA'ed the one.

Since that failure, I now drill a hole in the hinge slot to aid the CA to wick and draw a center line on both sides of the hinge with a crayon to keep the CA off that area.....plus I only use 3 drops a side and only use Great Planes 2" x 9" Ultra CA Hinge sheets, cut to 1.250 x 1" hinges.....a little bigger than normal, but lotsa contact area.

Remember Ca hinges are just a soft piece of nylon or plastic and if bent fast enough it will break just like sheet metal. Add CA to hold them in and some is bound to creep into the hinge line making the life even shorter. As we all know the kit makers know that they have to supply hinges, something that will work for a while and keep the modelers happy. but price also is a factor in the kit in other words they work but they are not the best in hinges. Other types cost more but they last the life of your Bird. They just take more time and work to install them right

A trick l learned when using CA hinges is using wax on the center of the hinge. It stops the CA from wickering into the part you want to stay flexable. I have even used crayons. If you look hard enough you can find a color that is pretty close to your covering. If you are using hinges with pins and are epoxying them in, then you can use petroleum jelly. Keeps the epoxy out and lubricates as well.

Cheers