Rudder

 
 
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Construction of the rudder begins with preparing the rudder drive plate. These parts are pre-made in the kit, with the exception of the small angle. The drive plate needs to be bent 5.2 degrees, so I clamped it into my vise and whacked it with my hand sledge until it looked right. I wouldn't get to worked up about getting it to exactly "5.2" degrees!
The lower ribs are fitted to the drive plate.
The small angle must be aligned with the flanges of the forward and aft ribs. I used scrap 1/8" aluminum clamped against the flanges to hold it while I drilled it in place.
All the holes were drilled out to #30, debured, and the parts were primed.
Completed rudder drive plate.
The rudder skin is made from a pre-bent section. I transferred the dimensions onto the skin for the tapered bottom edge and clearance cuts for the rudder drive plate.
I debated on how to cut the skin. Using the snips might be tricky due to the taper and tight corners of the skin. The edges may also get bent up from the jaws of the snips. So, I decided to cut it on the band saw. This worked ok, but right at the end of the skin the blade tended to catch and bend the flange a bit. Inserting a rib or some type of stiffener would help prevent this.
The band saw left a rough edge, and it required a bit of filing to dress it up. Even so, it was quick and turned out very well.
The snips were then used to trim the clearance cuts for the drive plate.
A little bit of filing and things fit very nicely.
Clearance cut from the other side.
Because the skin is a triangular section, it was not really feasible to prime the entire inside. Instead, I just sprayed the top and bottom inside edges so that the rib flanges were not touching bare metal.
The ribs were fitted using the same blue centerline trick on the rib flanges. This proved to be easy, but the skin had a big tendency to twist out of a flat planar alignment. I paid particular attention to this so that the rudder did not have a built in twist.
The hinge must be positioned 0.057" down from the surface. This is so the outer edges of the rudder and vertical stabilizer line up. To do this, I made a spacer from some scrap 1/8", 0.025", and 0.032". It's no coincidence that 0.025 + 0.032 equals 0.057". I simply super glued scraps of each to the 1/8" piece and then laid it on the surface of the rudder. The hinge was slid right up against the spacers, and then drilled.
The rudder components are re-assembled and are ready to rivet.
At this point, it finishes up real quick! This is my favorite part.
The rivets in the end of the rudder had a bit of interference. After the first rivet was set, the second one didn't sit flush. To solve this, I used my hand puller to partially set the rivet, which in turn caused it to shorten enough to push it all the way in. After it was sitting flush, the rivet was pulled the rest of the way and completed without further trouble.
Completed rudder sitting on my workbench. While riveting it, I finished off the first bag of CCP-42 rivets. 2000 down, 2000 to go! (Actually, those numbers are just CCP-42 rivets. In total, there are about 10,000 rivets!)
I just had to see how it looked, so I temporarily attached it to the vertical stab. I still need to fit the fiberglass tips, but it looks great all ready!

 

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Updated: 14 Jun 05