|This is the really disgusting component of kit-building--That awful
moment when you just have to go take a walk around the backyard while you cool off--Those
times when you say, "I CAN'T BELIEVE I DID THAT!"
Nothing insurmountable happened in the empennage construction. There were a couple of "Oh Shoots" in the horizontal stab sequence, so lets get this sorry mess out of the way.
Wait, before we go to them, let me tell you how to avoid many of these problems. The solutions are clearly stated in the construction manual but it is oh so easy to ignore them.
1) Don't get in too big a hurry! Yes, the kit arrived just yesterday after the longest weeks of your life, but take a deep breath and realize that this plane is not going to be built this month. Most mistakes I make are because I get "on a roll", things are just zipping right along, everything is right with the world and WHAM!, I overlook a detail on the drawing. What is really aggravating is that I had probably circled the detail with a red pen (I like to make notes right on the drawing as I preview the the construction step).
2) Preview the construction sequence and try to mentally walk through the process. WHY is that rib turned flange up? WHY do the plans specify flush head rivets turned the "wrong" way?
3) Realize that goofs are going to happen. This is my third kitplane, and one thing I have learned is that I am capable of making some incredibly stupid mistakes! Mistakes that if I had just looked at things one more time probably could have been avoided. There have been times when I have cut a piece of stock THREE times and it was STILL too short....
Full of vim and vigor and gung ho to get this little aeroplane project on the way, I managed to waste a lot of time on HS610 and HS614; Yes, the famous front spar splice plates. I wonder how many of these things Van's has sold. Let me take you through the thought sequence to show you how the obvious can become obscured once you develop a certain mindset:
1) HS 614 was machined with a couple of notches and HS 610 wasn't. A quick look at the
plans showed some dimensions common to both parts, so I reached the conclusion that 610
had to be machined just like 614.
As far as I can tell, the only reason for the ears on HS614 are to clear a couple of rivets on final assembly with the fuse. The extra ears in HS610 are of no consequence, except for the exasperation I feel when I see them. So no real harm done, but a lesson learned.
The other goof was caused by the same reason (guess I didn't really learn the lesson after all). Initial assembly of the tip ribs resulted in them being installed the pretty way, flat side out, which is also the wrong way. Fortunately, I was able to turn them around, the only problem being that one rib protruded 3/32" beyond the end of the spar when I used the original holes. The offending rib was simply trimmed flush with the skin upon final assembly.
During construction of the rudder I REALLY outsmarted myself! You know, some folks are educated beyond their intelligence. The skins come coated with a clear vinyl which does a great job of keeping the stock from getting scratched during the building process. However, the skin stiffeners are attached to the skin fairly early in the rudder sequence.
GREAT IDEA! Why not leave the vinyl on the outside of the skin until the skin is riveted to the spar? Eh? Eh? The rivets seemed to fit in the dimples just fine with the vinyl attached. So I did.
I still get ill just thinking about it. Excuse me while I calm down..............ahem..................ok.......... I'm getting everything back under control again.....
When I carefully removed the vinyl after the stiffeners were riveted, of course there were little tags of plastic that remained around the rivet heads. Even after considerable picking at the tags, they still were noticeable. Soooooo, out came the Scotchbrite pad and all the rivet heads were treated to a free rubdown. This removed nearly all the tags. That is when I noticed that the rivets were sitting a little higher than the ones I squeezed after the vinyl was removed.
Oh well, I am not in the mood to surrender just yet and rebuild the rudder, so I am going to hang in there and see what the rudder looks like after it is painted. I suspect it will look ok to everyone except me and those few folks who perform an anal, er, I mean annual inspection on your plane at flyins.
Needless to say, the vinyl came off before the stiffeners were riveted to the elevators.
So we press on......
The remainder of the emp kit went well. Matter of fact, it wasn't until deep into the wing kit that I made another skid. This occurred when drilling the mounting holes in the aileron support brackets. The aileron is hung by two steel brackets, one about twice as wide as the other. The narrow bracket gets two 3/16" holes drilled on center. In a flash I had those holes drilled and quickly yanked up the wider brackets and drilled three holes on center in them per ONE of the details in the drawings. Uh, oh........When I placed the wide (inboard) brackets on the aileron for test-fitting, I remembered why the half-moon cutout was made in the tip rib. The holes should have been staggered per the fabrication detail of the bracket drawing.
Same old Same old. We MUST look at ALL details of the drawings before committing drill to metal. The details are a lot like an Easter Egg Hunt, some of them are hidden in the most unlikely places.....
And I almost made it completely through the rest of the wing kit without a
I think I just executed the worst "stupid" so far in my project. As I was riveting the first aft side skin, the gun slipped off one of the rivets along the curved portion that is near the bottom of the fuse. The resulting ding really hacked me off since I am seriously considering not painting my airplane in the near future. I turned the air regulator down a little more and continued riveting. A while later, the same thing happened again; The gun bounced off the rivet and another ding resulted.
Yep, a few rivets later, it happened again! Three smileys on one side of the fuse! After walking around the shop a few times and engaging in self-flagellation, I started wondering if I had lost all the riveting skills I had accumulated up to that time.
Then it hit. I have three air outlets in my shop, one set at 80 lbs, the others regulated at 25-35 for the gun. I was wondering why I had continued problems with the gun bouncing even though I had reduced the air pressure after each of the dings. Yes, I had plugged the rivet gun into the wrong air line!
Fortunately, I found my brain sitting on the workbench before it had time to dry out completely, and after reinserting it into my head, I continued with the riveting session without further problems.
Now I need a good method to work out dings without resorting to filler. Any ideas?