Wednesday, March 12, 2014

Empennage - Rudder - Day 2

So I took the day off yesterday from doing any actual building. I did, however, have my EAA Chapter 33 Tech Counselor, Tom, over to my house for the first time to show him the workshop and what I've got accomplished so far. He seemed happy with just about everything, but he did point out that I haven't been hitting the dimpler hard enough with the hammer when dimpling the 0.025" thick skin of the VS. Good thing it isn't attached yet, should be really easy to run through the C-frame again, this time with a 2lb ball peen hammer. (I had previously been using a 3lb rubber mallet... apparently you don't want to use rubber mallets for the job, who knew?) The only other finding came when I pointed out 2 rivets on the VS main spar that didn't come out 100% perfect, and I wanted to know how close they were to rejection-level. He said they were fine as is but if I wanted to I could drill them out and replace them, just to get the practice and have the extra peace of mind. I figure I might as well, it can't hurt anything.

Last night I also ordered the parts for the rudder trim. This will be the first add-on I will be attempting that is not in Van's Plans. My idea for rudder trim will be to do something similar to Brian Steeves' post but use a longer pushrod and mount the servo closer to the front of the rudder to minimize potential control surface balance issues (but also the slightly larger/heavier/cheaper RA servo). There's also an interesting post going on currently on VAF that I'm paying close attention to, I might incorporate some of the things I'm reading in there too, we'll see. My bill of materials for rudder trim so far is as follows:

Ray Allen T2-7A Servo ($145.00)
Van's VA-195C/D inspection plate doubler and cover ($7.10)
Van's AN257-P3X3' hinge ($7.50) will only need about 7" of the 36" part
Avery fairing set ($16.00)
Click Bond Studs ($9.65)

On to today... we nearly completed the metalwork for the rudder. We started by clecoing on the skins to match-drill all 4 billion holes in the skin. The plans said to use a cleco in every hole, so that we did. Sarah and I spent the first half of this task figuring out a system to communicate which holes still needed to be drilled, and which ones needed a cleco removed or inserted after drilling, etc. By about the time we got the rhythm down, she wanted to switch roles from clecoing to drilling, and the learning process started over again :-). We're having great fun putting this stuff together though! And the resulting rudder appears to have come out quite straight and looks pretty neat:
The rudder with the skin fully clecoed into place. Notice the empty cleco bin on the stool to the right, we literally used every 3/32" cleco we had! Maybe it's time to buy more...

After finishing up all the match drilling and clecoing, it was time to tear it all back apart and begin the painstaking deburring and dimpling process. I set a cutoff time at midnight for today, which got us through everything except for dimpling one of the two skins. Should be about 20 more minutes of work tomorrow, then the rudder will be ready for priming and final assembly!

The parts needed to build an RV-10 rudder, minus one of the two skins. All parts here are cut, deburred, match-drilled, deburred (again), scuffed, dimpled, now ready for priming and final assembly!