Sunday, September 11, 2011

Wing repair

Ok, so in my last post, I had issues with my wings starting to buckle at the end of the wing spar and where I cut out for the aileron servos.  I finally decided to repair this by cutting a slot in the wing and inserting a support in the form of a bamboo rod.  Not something really special, just a couple of bamboo cooking skewers!

I really had some issues with how I would cut a groove for these bamboo rods.  My original thought was to use my razor knife and cut a track of foam out of the wing.  Although this might have been the easiest way to accomplish this, I did not want to remove foam from any part of the plane anymore.  My thoughts are that the removal of foam will lend to the weakening of what ever part it is removed from.  So my ultimate decision was to modify my soldering iron and to use it to melt the foam out of my way.  My theory is that the melted foam will maintain the strength of the part but allow for the modification.  So I removed the original tip from my soldering iron and created a new one from a nail and inserted it and set the tightening screw.

After I came up with my final location for the re-enforcement rods, and laid out some markings, and removed the support tape covering this area of the wings, I was finally ready.  I got out a metal straight edge (the back of a steel saw blade).  Lined it up with my markings and began to cut/melt the foam and open the slot for the bamboo rods.

I performed this task on both wings and was pleased with the results. Now it was time to affix the rods. I simply used my hot glue gun to lay a bead of glue in the slot and quickly inserted the rods. Then I laid in some more glue on the top side to ensure the bond and to fill in any gaps.

Now that this was all done, I re-taped the wings with fiber strapping tape from root to tip.  Re-installed the aileron servos and taped down the servo wires.  All ready for a test flight!

UPDATE:
Testing went very well and I am happy with the results!  I have been able to fly in heavy wind and do stunts pulling heavy G's without any wing issues.  I feel that melting the foam had added extra support to what the bamboo rod adds and makes for a better repair.

Thanks for stopping by my blog and please post comments, good or bad.  Be sure to come back and check for future posts.

2 comments:

  1. How did it go? I hope you were able to fix it to flying condition again. Did your theory about melting the foam prove to be correct? You could've considered other methods of holding wings in place while you were waiting for the results. Plastic strapping can be an alternative since it's easy to handle and is durable enough to hold the piece together.

    Thelma Bowman @ Quality Strapping

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    Replies
    1. Thelma,

      This fix worked great! I have flown this airplane a lot since then and in heavy wind. I don't even worry about wing flex any more. I probably would have been just as successful in just cutting the foam out with a knife but this method worked just fine and I feel better about doing it this way. I already had strapping tape on the wings to begin with so it needed the extra support.

      Thank you for your comment.
      MrClean

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Mr. Clean