Well…Just in case you think mounting the HS is tricky and frustrating. The vertical stabilizer is every bit as much so.
Reading ahead on other build logs, it seems many choose to fit the F-781Vert. Stab attach plate to the horizontal stabilizer. And frankly why not... trying to get all the clamps in that area is a bit of a pain. So why not do it now, If anything just drill it to #30 and cleco.
I drew out the centering lines on the attach plate and then clamped the plate to the HS. Sure enough... the center lines were running straight through the pilot holes in the HS spar.
Once happy with the fit, I carefully made small drill marks in the plate.
Drilling one hole in the drill press. Re-fitting, checking, removing, drill the second. Repeat the process and eventually I had all 4 holes drilled to #30 and cleco'd into place.
At this point I need to get the proper height of the VS set. The plans have a dimension from the top of the bottom hinge to the top of the longeron (7 11/32"). After some careful measuring and marking. I have the reference lines drawn on the VS rear spar. I also drew a center line on the inside VS spar itself to help with aligning with the Aft deck center.
Now to clamp the VS to the fuselage. It becomes really apparent that the VS interferes with the HS, so I will need to trim down the VS-702 spar. The plans indicate 5/8" however many people report to remove much less....van's technical support being another one to advise me not to trim too much on an earlier tech support call. I started to remove 1/4" and fit the VS temporarily. Still to much interference with the HS so I trimmed a little more just under 1/2" I was getting the VS to just touch the top of the HS spar while getting a straight edge to alight all three hinges on the VS. Perfect!!!
Critical - Do not make the mistake I did...When you fit and trim the VS you do so with the VS aligned with the centerline of the aircraft. So it seems like you know the correct amount of the spar to trim. Be careful....Once you offset the front of the VS over 1/4" left of centerline all of a sudden the VS-702 no longer touches the HS. Magically you've just lost some length on your VS spar. In my case...I went from being on the good side of edge distance on the spar, to now blowing edge distance when I moved the VS over 1/4".
Final fitting the VS is not a fun or easy feat. Also making sure the VS is centered in the F-712 bulkhead makes for some fun. Everything wants to move and getting it solidly clamped is a process and a pain.
Now, take a tape measure and measure from the top of the VS to the edge of the HS on each side and get it perfectly level. Not a process that is quick. Lots of adjusting, measuring, repeat, again and again. Eventually I ended up with a placement that I feel was the best I was going to get. Now I need to drill the first 4 pilot holes down inside the fuselage. Not easy to do even with a 90deg air drill. I managed to get pilot holes drilled with #30 bit and allowed me to remove the VS and finish the holes with a drill jig. The top holes where drilled. The VS reinstalled and cleco'd. Reclamped, remeasured....then the bottom two holes were marked, removed and then drilled.
All that work to drill 4 holes to #30...but it looks so good.
