Tuesday, July 17, 2012

Rudder Skeleton Completed

Today was a productive day at DOG Aviation in spite of a late afternoon start. The rudder skeleton was assembled and, here again, I substituted a stronger (and lighter) solid rivet for the LP4-4 blind (pop) rivets called for in the plans to attach the rudder's ribs to the rudder spar. My pneumatic squeezer was able to access all of the rudder's rib rivets, so decided to make a substitution. I used a rivet gauge and determined an AN470AD4-4 rivet would work well so that is the size I used.
                                              First rib riveted along with the spar caps and rudder hinge rivets.
                                 Photo of the rivet gauge - an AD470AD4-4 rivet looks to be about the right size.
                                 When forming a shop head on thinner material using a piece of vinyl tubing over
                                the rivet keeps the thinner metal from riding up as the rivet expands … works great!

Clicking on the photo to make it larger one can clearly see the rib to spar joint is tight together where the upper three rivets have been already squeezed. However, getting that little piece of tubing to stay in place can be “challenging” … patience is a virtue when using this method.
                                                 Squeezing the last rivet where the rudder horn to attaches to
                                                 the rudder spar. This completed the rudder skeleton.
                                        Sliding the rudder skeleton into the rudder skin - paper is placed in the skin
                                        to prevent the primer from being scratched while the fit is adjusted.