Fuselage - Page 2 of Fuselage.
I split the Fuselage into two sections since it was getting kind of long.
Everything prior to Tail mounting is on "Fuselage 1" page.
(7/23/06) With the fuselage leveled at the top longerons, spar box, and front-to back, it really looks like there is a slight twist to the fuselage. Everything is zeroed, as shown, until you get to the HS mount platform. That's 1/2 a degree low on the left side, which tranlates into almost half an inch low on the left, and half an inch high on the right at the HS tips. In order to correct for this it looks like I'll need almost an 0.040 shim on the left, which seems like quite a lot, or to shave the right 0.020 and add an 0.020 to the left. Again, something I will confirm with Van's before comitting drill to aluminum in this critical operation.
I called Mike Draper, who is a little ahead of me, and has a QB fuse received about the same time as mine, and confirmed that he, too had the same issue, but only required a single 0.20 shim to correct. Apparently Van's jigs in the Phillipines must be off a hair.
Did I mention that this is the coolest level in the world! This would have been painstaking to try to judge with a bubble level, especially with my aging eyes.
(8/05/06) After fiddling and diddling with the alignment the HS is mounted. In the horizontal I read 0.1 degrees off, but if I just rest my finger on the level, it zeroes, so it's right on the edge. Well within tolerances, certainly. I did not yet drill the interior two bolt holes on the front mount angle. I'll have to crawl inside and come up from the bottom to get those. The outsides are done and well aligned.
(8/12/06) Now it's time for the Vertical Stab. I clamped everything together and got it all aligned. The front spar is loosely in place. The key vertical dimension is defined as 8-1/8 inches from the top surface of the lower hinge bracket to the top of the upper mounting angle.
Once it all looked good, I reached in and marked the hole location for the lower bolts. Those holes had been pre-drilled in the tie-down bracket per the plans, and I had previously riveted the bracket to the rear bulkhead. I had then drilled the pilot holes through the bulkhead for the VS bolts.
When I pulled it apart to check the hole locations, I found that they were very low and violated edge distance to the edge of the rear VS spar. After staring at it for a while, I determined that I must have mounted the tie-down bracket too low. The only hard dimension given for this is relative to the lower edge of the VS rear SPAR. In hindsight I should have first test mounted the VS and used the VS spar to indicate where to mount the tie-down bracket. When I mounted it I placed it flush with the lower skin, based on what it "looked" like in the plans. Clearly this was wrong. Unfortunatley, as with so many mistakes in building, the clarity is only apparent in hindsight.
I can see how I made this mistake since the detail in the plans and the instructions don't generally include sequencing information. The lesson is to think more through the sequencing and implications of the steps. The easy way to deal with this is to lower the VS until proper edge distance is achieved. This approach transfers to potential issues of clearance at the fronts of the VS and front spar clearance issues.
The harder thing to do would be to drill out the tie-down bracket and make a new one with offset holes. The hardest thing to do would be to replace the entire rear bulkhead since my new offset holes would certainly be very, very close to my already drilled pilot holes and clearly a volation of hole to hole distance. I've posted my quandry to the Yahoo groups and will probably also call Van's on Monday.
(9/16/06) After fiddling around with the alignment and mounting, I drilled the holes. That's my second vstab angle. The first was a little small. Red headed bolts are temporary bolts not to be used for final assembly. The nuts are drilled out so there are not locking. This thing looks like an airplane!
I decided to now work my way forward, starting with the rudder and elevators, then fit the appropriate stuff into the fuselage as I work toward the engine. I found a mistake made when I built up my rudder. You have to look close, but I put the fairing mount strips between the skin and the rib, instead of inside the rib. Duh! This was easy to drill out and place correctly, and boy did it help the fairing fit properly. Just that tiny change made all the difference and was a much better fit on the skin. Less chance of cracking.
Playing with fiberglass is very unlike aluminum. There is a lot of fitting and trimming to get it to sit right. I purchased some small, single-legged #6 nutplates and fit them inside the light cutout to secure it in place. It really looks nice when fit together.
The front cut is not as pretty as I'd like. I'll go back to this during the final finishing and probably tighten up that gap between the fairing and the rudder horn angle. A drain hole, sime filler, and I'll be done - for now.