2004-09-19


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Today I spent a lot of time doing this.

(update 11/18/2004) when you get to this step, make sure that you have the correct HS-710. There were a number of empennage kits that went out with the wrong part here. Jim Diehl was kind enough to send me this picture of an INCORRECT Part which, unfortunately for him, came in his kit. 
All nice and clean! I started out by filing the edges until they're smooth, then I scotchbrite the edge to knock and remaining corners off, Then I take it to the drill press and go over the whole surface paying particular attention to the edges. 
Guess I need a new one of these.
So, now onto drilling the horizontal stabilizer. I choose the left and right ribs and marked them as such. 

"Using the dimensions given in SEC-DD, mark the hole locations on the forward side of the forward flange of HS-405. These holes attach HS-405 to the forward spar assembly and HS-404. Mark a light mark with a center punch to keep the drill bit from wandering then pilot drill the holes to #40. Note that the uppermost attach hole is not centered on HS-710. Position this hole as shown to ensure proper edge distance on HS-405."

 

Huh?
I took me a while to figure out what this meant (longer than usual). If you look at the drawing at SEC D-D it kind of shows you where the holes go, but the way it's dimensioned seems a little odd to me. As I thought about it, the drawing seems to be stressing the fact that the holes are 1/4" away from the edge of the flange. SO that must be the important thing.  
One problem I seem to have is the fact that the clearance cutout in HS-404 to clear around HS-714 is way  bigger than the one for HS-710. You can see from this photo that the clearance is about 1/8" instead of right up tight like HS-710. The only implication to this is that the hole has to remain 1/4" from the edge of HS-404 which moves it closer to the center than the drawing shows. Not a big deal, I just marked the centers of the hole right on HS-404. 
Then I transferred the marks to HS-405. Another thing that was a little less than clear to me was the fact that these #40 holes are only going to be drilled thru HS-405. I had to read quite a bit ahead to figure that one out. I've been reading ahead a lot, it helps.
Naaaa, this ain't going to work...
I transferred the marks to the other side of the flange. I'm holding a block of wood against the back of the rib and resting the block on the bench. Piece of cake.
After making sure that my left and right HS-404's had the same cutout clearances, I just transferred the holes from one HS-405 to the other. 
NOW for the good stuff. Cleco together HS-702 HS-603PP, HS-706, HS-707 and HS-708. 

Too cool not to take a picture of. 
Now drill all rib-to-spar holes with a #30 drill, take it all apart, deburr all of the holes you just drilled and then cleco it all back together.
For about a year now, since I first started reading peoples RV websites, I've read about this technique for removing only the blue plastic from the alclad that you need to remove to work on the part, but leave the rest to protect the alclad from getting scratched. I couldn't wait until I was doing that too. Well, Now I'm doing it and guess what. It works way better than I thought it would. The soldering iron melts a nice gap in the plastic and it's a cinch to remove. For you guys who have never seen this technique before, well... I thought of it! Yeah, that's right, it was MY IDEA! 
Comes off real easy.
Kathryn came into the shop and saw what I was doing. "Hey, that looks like fun! Let ME do it!". So now KK's an expert at removing plastic from ALCLAD.
Clecoing the HS-601PP skin to the ribs and spars was a bit arduous, but it just needed a little persuasion.
Man-O-Man, does this look like a piece of a plane or what. I put a cleco in every hole at the leading edge. This made it easy to put the rest of the clecos in since the leading edge was forced into shape around the ribs.
That's it for today, I'm going to take this piece outside and see if it flies