Rudder Finished

In the evening of Memorial Day, I got to finish riveting the other side of the rudder and summing up the hours. Not much else to report. The rudder took me 14.5 hours to complete, including the prep work and the priming.

Finishing the Rudder

The next day I rushed out to the shop to get that rudder finished. Everything was prepared and I was eager to get this part done.
With all the knowledge acquired from the other blogs I had the feeling that I was well prepared and that I knew what had to be done.
And indeed, it really worked without a hitch! Only the day was a bit too short. In the evening I grew tired pulling all those pop rivets and I just finished attaching one skin to the rudder and left the other one for the following morning.

The Rudder and Schmetterling Aviation

I started the rudder by preparing and prepping all parts as the number of parts is very low and it was easy to read ahead and see what I was supposed to do to finish this quickly. Now that I have the primer I want to reduce the amount of time spent to clean the spray gun and that is by collecting as many pieces for a spraying session as possible.
So, I match drilled, deburred edges and holes as far as possible until it was time to rivet - oh, wait! There was this one really awkward step in building the rudder. And that was to trial fit the clecoed rudder spar to the already finished rudder (you'll need to have finished the hinges - remember?).
There was no hint in the manual how in the world I was supposed to fiddle those handful of washers into the different places they were supposed to go into with just my own two hands! With a lot of patience (did I mention that I'm not good at that?) and calm hands and some sort of nihilism I finally put them all where they were supposed to go and ..... it just matched perfectly! It revealed that the travel stop for the rudder which is built into the lower hinge assembly was not even on both sides and the rudder horn did not rest on a large area on that stop on one side. This would cause some wear on the aluminum part later and as I had the upside down (and the downside up), I could easily trim this little thing to make it a flat fit. I quickly reprimed it to cover up the blank aluminum and that was that.
After all this time spent on putting it together I had a hard time to disassemble it - knowing that I would have to do this again some time far away. With a muffled sigh I did what I had to do and continued on to finish the rudder.
Now, as I am following other builder's blogs and websites, I was aware of two major problem I could have run into. The best (and most entertaining) description of these are from the Schmetterling Aviation blog maintained by Dave. He's quite a bit ahead of me and he seems to interpret Oregonian in the same way as I do which means we both seem to scratch our heads about the same manual instructions and run into the same problems.
Reading ahead in his blog told me that some of the rivets I was supposed to use where a tad too long and tend to bend (in a spot where drilling them out is not so easy) and that putting the shop head on the outside of an assembly can avoid the the thin ribs from separating from the opposite part. Be careful about the rivets that connect the rib to the spar where the spar caps go on (put the shop head outside (so that they're visible after assembly) and take extra care to shorten them to the necessary length as they're a bit too long. Also, when riveting the trimmed rib to the rudder horn, make sure that you put the shop head on the side of the rudder horn back plate although this won't look as pretty. Otherwise the rib will try to separate from the rudder horn back plate and this could be a structural issue (the rib is just a bit too thin to stay straight when the rivet forms the shop head).

I got everything prepared and ready for final assembly and then the day was over. The primer got some time to dry overnight which is good as the inside of the skin won't dry as fast as open parts.

Hinge Nightmare

After the primer had dried over night I started the shop day by putting together the upper hinge assembly to finish the V-Stab.
Clecoed everything together and then rivetted the thing with AD4 rivets. After doing the three closest to the bearing I tried it to see if the bearing was still moving freely.... and: Damn! It got stiff again and would hardly move at all. The same problem I had before.
Thanks to the Van's Airforce website I had found out that the only reason why the bearing could lock up is pressure from the cage surrounding it. I checked the assembly again after drilling out the three rivets and I found a hint of primer on the inside of the assembly right where the bearing is sitting on. I could hardly believe that this little could have such a huge effect but I was getting desperate and in lieu of another clue I went on and scrapped off the little paint spray dust that got on it. Once it was all shiny on the milled surfaces again I put it back together started rivetting and .... you wouldn't believe, it worked!. I set all 5 rivets and the bearing was moving freely just like before when the hinge had been clecoed.
So, be careful with the milled surfaces and make sure they are totally plane and clean before wasting your time on it!
The image shows the finished upper hinge assembly next to the primed parts of the previous attempt (notice the thick layer of primer in the bearing cut outs) and also visible are the unmodified parts of the hinge as Van's sent me an extra set of parts.

Screwing on the hinge onto the V-Stab was a piece of cake after that. You'll see pictures of the whole assembly when I trial fitted the rudder spar to the V-Stab.

Preparing the Rudder Ribs

So Van's had sent me the replacement parts to rebuild the upper hinge assembly for the V-Stab and so it was prep time again. As I wanted to prime the parts I took care of some more parts as the rudder ribs got drilled anddeburred and were ready for priming as well. As my Cortec primer finally arrived I wanted to use this expensive stuff and see if it really works wonders or not. This type of primer (Cortec VcPI-373 and the surface preparation with Cortec VcPI-440) is supposed to be applied with a spray gun and I had to learn how to use this tool before I felt good enough to try it on the real parts. I'm still learning the little details but for primer work I'm doing good enough.
I have to say that I'm pretty impressed by the Cortec stuff. Environmentally not too harmful, no nasty fumes and still a great result on aluminum.

V-Stab finished... almost

And so I finished riveting the skin to the V-Stab the other day. Nothing surprising happened (I consider this a good thing). The only noticeable thing that happened was that my shop A/C broke and with over a 100 degrees it's a bit too hot out there to work without it. A replacement unit is on the way (the first just got 3 days old before it broke).
Fitting the nose of the V-Stab looked like a real bad job but when I screwed it on it just pulled itself in place. NICE!
So that was it with the V-Stab - except for screwing on the upper hinge assembly which I can't do as the parts are still on their way from Aurora. The previous parts couldn't get riveted without causing the bearing to freeze up,
On of the first assembly steps for the rudder is to trial fit the hinges with the rudder fittings and I don't want to get too far ahead this time. There might be a reason why Van's wants you to do it before assembly.
So, I'm limited to deburring and finding a place where to store all those parts I will eventually have assembled ...
Overall time for the V-Stab was around 35 hours.

Stabilizer skinned

In the morning, before going to work, I finished squeezing the last 9 rivets for the nut plates. I just couldn't let it sit like this.
In the evening I put the skin on and the fit appeared to be good. So I continued clecoing the skin on, beginning from the leading edge on one side. Everything looked good but I wanted to be sure and so I turned the Stab and tried to cleco the other side as well (raising the Stab on some coffee cans to clear the clecos from the workbench). After I did that I was pretty amazed that it looked like I was already ready to rivet the skin on - but then I noticed little buckles near the leading edge in the front areas of the ribs. It wasn't the radii that had been excessively trimmed in the previous steps, it appeared to the be the ribs being too long and the upper front pinched into the skin. So I took the skin off (oh my, why did I have to send my air cleco tool in for repair TODAY?) and the scratch marks on the inside verified that it was the rib webs being a bit too long. The die grinder took care of that and I made sure I wouldn't have to do this cleco party again! Scotch-Brite polishing, re-priming the rib noses, priming the inside of the skin, particularly where it got scratched and along the rivet lines didn't take long.
Then re-skinned, aligned and adjusted and finally riveting started. I got as far as finishing one side and starting the leading edge on the opposite side. The process is a bit slow as you have to go one by one in the leading edge area because of the high tension there.
Anyway, the V-Stab is almost finished!