Saturday, June 2, 2012

Rudder Repair

 I ordered some pieces of tubing I need to finish the stabilizer, so while I wait for them I decided to repair the rudder.  The trailing edge tube has been repaired, badly, a few times and is missing a section.  I bought enough tubing to build a new one but I would like to have as many original parts in the plane as I can.  The first step was to layout the the rudder on the jig I made for the horizontal tail.  The board needed to be a little wider so I added a piece of wood to one edge.  The balance horn part of the rudder is in good shape or I would have needed to build a whole new jig board to get it all to fit.  With the layout complete I formed the new trailing edge from 5/16" tubing using the same methods as the elevator Trailing Edges and Stabilizer Leading Edge.
 With the new trailing edge formed I'm ready to cut off the old one. The top section, the middle section and the bottom section have all been damaged.  The ends of all the ribs are still the factory welding which makes it easy to see how it was all done.
 I used a 3" cut-off wheel to remove the trailing edge.  I left a little of the trailing edge to clean up with better tools.  A 4" grinder, mill file and rat tail file worked great to clean off all the weld and trailing edge tube.

 Everywhere I opened tubing it was in great condition.  To see how the bottom end of the Trailing Edge was attached to the Spar I removed the piece closing the bottom end.  The trailing edge is welded to the back of the spar and passes through to the front but is not welded to the front. The tube is clean and free of rust.
 The spar is clamped in place on the jig.  I started fitting the Trailing Edge at the bottom so splice at the top could be made to fit better.  It's clamped in place as are the ends of the tubes.

 The splice at the top is made at the top of the spar so there is more to weld the ends to than just each other.  I also fit a piece of 1/4" tubing inside.  I'll weld it into the joint.

 The 2 tubes for the top rib had a lot of rust near the rear end so I've cut them off and will splice on some new tubing.  Again a piece of 1/4" tubing is sleeved inside.  To keep it positioned while sliding on the new tubing a small hole was drilled and a piece of weld rod inserted as a temporary stop.  I'll weld up the holes.
 Everything is fitted up ready for welding.

I got it tack welded before I lost the daylight, so I'll finish welding in the morning.  I like it.

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