Fixing live hinges
 

Hi guys

I was checking out the wing of my jet yesterday and I saw that the live hinge of the aileron of one wing has broken a little less than an inch, and on the other wing it looks i will start breaking soon.

Is there an efficient way to fix this (using kevalr tape for example), or the only way is cutting it out and installing balsa blocks and Robart pin hinges?.

Thanks in advance for your input.

Eduardo

RE: Fixing live hinges
 

A lot of views, but no posts.

Anyone care to comment.

Regards
Eduardo

RE: Fixing live hinges
 

What jet? Do you have a photo of the area?

RE: Fixing live hinges
 

I had the same thing happen to one of my ailerons on my L-39. During the repaint, I fixed it using a CA hinge glued underneath the hinge line. Be sure to have the aileron straight when you do this. Mine is rock solid now. You can't tell there was a problem since all the work is done inside the wing. I'll check to see if I took a picture.

RE: Fixing live hinges
 

I had the same problem on my Skymaster Gripen on both the rudder and elevon. I cut the rudder out and installed CA-type hinges along the complete length (approx 6") of the hinge line. I only needed to install a couple of inches width of CA hinges on the elevon. As Dom says, make sure that the control surface is straight. Also, I'd suggest putting a bead of oil on both sides of the remaining live hinge line to prevent any CA from getting into the hinge line and hardening which will cause the it to quickly break.

Regards,

Jim

RE: Fixing live hinges
 

I had some carbon kevlar weave. I pulled the strands of kevlar out. Cut them about 1" long. Spread them out 90 degrees to the hinge line and hit them with thin CA. Works like a charm.

RE: Fixing live hinges
 

Pardon my ignorance, But what is a "Live Hinge" ?????? Never have heard that term before...[sm=confused.gif]


TIA,

Danno

RE: Fixing live hinges
 

its when the wing and aileron or other control surfaces use the skin of the wing as the hinge. As in composite airplanes like the comp arf flash. When you look at it, all you see is a crease where the hinge line is. Like folding a paper airplane and then bending an aileron on it or to that effect.

RE: Fixing live hinges
 

Thank you for your input, I would appreciate picture of the fix if you have them.

The jet is a Hawk and below are some photographs.

Regards
Eduardo

RE: Fixing live hinges
 

O.K. ... Got it !!! I built a couple of Eurosport's that use that... Just threw me cause I've never heard it called that before !!! Oh well, learn something new everyday !!!!... Thanks for the answer !!!

Danno

RE: Fixing live hinges
 

If its just a small area that needs repair would a bead of silicon mastic work, I have used this as a hinge material only on some fair sized prop planes, but not on a fast jet, just thought as it may only be a small repair????

I know I am going to be shot at with this suggestion, but my sholders are broad.

Mike

RE: Fixing live hinges
 

hello::)

I think that you can repair if use the same hinge nylon and cover it with fiber glass (for the botton side, not over the paint.:D )

For you are sure that the hinge run perfect you paint the center of the nylon with wax paint for childrens, do you know ? this way the epoxi not glue in the center and the hinge will work perfect.

you an see it here:

http://picasaweb.google.com/cmjets20...40381312378482

Try it. I hope work fine.

Regards from Spain;)

Carlos.
______________________________
http://cmjets.blogspot.com/

RE: Fixing live hinges
 

No shots from me, good idea! In any case it will probably prevent the hinge from tearing more.

Hans

RE: Fixing live hinges
 

I had the same problem on my SM L39 elevator[:@]. I repaired it using a silicon bead on the inside of the hinge. I have not had a problem after that. This system is used by the glider guys as a hingeing system for awhile. I was doubtful and made up a test piece using two bit of scrap fibreglass and left it to cure for a week. There was no way that I or anybody else could pull the joint apart on a strip about 3 inches long. Try it for yourself and you will be amazed. :D

RE: Fixing live hinges
 

Here's a neat way to install CA hinges accurately:

http://www.rcuniverse.com/magazine/a...?article_id=55

Gordon

RE: Fixing live hinges
 

Link to silicone hinge - http://www.rc-soar.com/tech/silicone.htm

RE: Fixing live hinges
 

Thank you for your input guys

Eduardo