• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

Aileron Hinge Assembly

scottly

Well-Known Member
*
Joined
Sep 13, 2006
Messages
1,638
Reaction score
4
I first drew the image of the aileron hinge side plate in a CAD program of my choosing.....a simple ruler and pencil would work also. Then cut out the image and glue them to some .063 4130 steel sheet. Make sure you keep the bend line oriented with the grain of the steel.


After cutting out pieces, you must bend them. Remember,you are making 8 hinges so MAKE SURE YOU MAKE 8 RIGHT_HAND PIECES AND 8 LEFT_HAND PIECES!!!!


Before you bend,clamp all the left's together and all the right's together.....drill them while clamped together. This ensures correct hole location for the next step.


Next... I built a jig. It had to hold the two side plates and hold the tube at the required 28deg angle. So here is what I came up with:


20070918_185156_ailer&



You then bolt the two pieces to the jig....


20070918_185253_ailer&





You then insert the tube between the two pieces, letting it rest up against the 28deg angled block of wood.


Now, let's discuss the tubing......the plans call for .035 wall, 1/2"od tubing. WHat I found while trying to weld this tubing to the plate is that if not extremely careful, you'll burn a hole in the tubing....If you lower the heat, then you don't (in my opinion) get sufficient penetration int he side plates. I was using a TIG welder. I tried a torch....I burned no holes, but was not happy with the penetration I was getting, and sine I'm flying it, it has to meet my standards or it doesn't go.


To solve this, I used .095 wall 1/2"od tubing. This allowed me to get sufficient penetration in the tube and the outer plates.




A big weld bead is not necessary....all you need is about 1/2" on each side, like so:


20070920_164156_ailer&



To test this theory, I bolted this hinge to the side of my workbench. Using a 5lb slide hammer, I inserted a threaded rod through the tube and secured a nut to hold it. I then banged the hammer until I started to pull the bolts through the 2x6 bench frame....no weld or bracket breakage. Of course, I will not use said test piece on my plane.


When you are done, you should end up with a pile like this:


20070918_190547_ailer&





Now, here's where you do something else different than plans...and save a few bucks. The plans call for RE3H5 rod ends on these hinges. The plans show this hinge as inserted into the tube and two rivets are used to secure it.


Now, this will not fit the thicker wall tubing you just welded...so what to do? Order the RE3M6-2N Rod Bearing. It is the same specs, only it has a threaded end instead of a hollow shank.


You drill the tube 1" deep with the proper size drill for a 3/8-24 tap (21/64", roughly halfway between a "P" and a "Q" wire drill). You then tap for 3/8-24. This will allow you to screw the rod end into the tube. Like so:


20070920_164246_ailer&



Stay tuned and I'll post the drilling for the securing rivet (only 1 needed), and show you the jig I use to insure correct depth setting on the rod end.Edited by: scottly
 

Latest posts

Top