<June 12, 2005>

Assembly and Dilling of the Horizontal Stab

I finally made it into the shop and got some real work done! I managed to get in about 7 hours of construction today, and got a ton of work done! A very productive day.


After placing HS-405 in its spot and making dots for the approximate hole locations, you flute the rib, then mark a centerline for the rivet holes (yet to be drilled).
After marking the centerlines, I clamped HS-404 and HS-405 in place in preparation for drilling.
After drilling the aft, top and bottom flanges of HS-405, you need to clamp the forward flange in place to prepare to drill the dreaded HS-405, HS-702, HS-404, HS-710 (HS-714) union. Take your time and be careful here. You can see where HS-405 has already been pilot drilled. A word of caution... be mindful of your edge distances on HS-404 when you mark HS-405. If you mark the interior two holes on HS-405 wide, then overtrim HS-404, you might end up with edge distance problems when these are match drilled (see below).
Here you can see the aft flange of HS-404 clamped in plance ready for drilling
Wake up! You're supposed to be helping me.
I don't have and angle drill attachment so I used my dremel tool to pilot drill these holes.

Here is what the aft flange of HS-404 looked like after pilot drilling.

I then used my 12" #30 bit to drill out the holes, drilling fore to aft.

Here was the second (right) HS-404 after drilling, I am not to happy with the edge distance on the right hole, but I think it will be okay and am not going to worry about it... build on! Lots of people have issues with the edge distance on this flange. If I had to do it over again, I would move the two interior (HS-405/HS-702/HS-404) holes in a little bit as I think the tendency is to overtrim HS-404 (like I did) resulting in edge distance problems when these are match drilled.

Hey Mr. FAA... Look it's me! Here I am match drilling the skins. I took the advice of another builder and used a reamer instead of a drill bit. It seems to produce smoother holes with less burring. I was real happy I bought the pnuematic cleco gun as there were lots of clecos to move today, and you can do it very quickly and easily with the gun.