706 Bulkhead
At this point I spent WAY too much time searching for all the parts of the 705 bulkhead. The problem was the 040 sheet that makes up the 705K, I just could not find it anywhere! eventually, weeks later I did find it, underneath a bunch of other stuff of course. Lesson learned, when you inventory, make a note of where the parts are stored, and then don't move them! It is VERY annoying to be stopped by something so simple. Anyway, as i contemplated ordering a new piece of sheet, I opted to continue with the remaining bulkheads, so on to the 706.
this is seemingly straight forward, yet I made my first major mistake of the fuselage here. These are the parts of the bell crank support structure clecoed together.
IMG_0588 by
Ed Fleming, on Flickr
This was a minor problem. I had insufficient edge distance on the first 729C to 729B rivet hole. This could have been avoided if I had made 729B a little longer, or positioned further forward. It was a reminder that vans dimensions have zero tolerance. Accurate cutting and positioning is a must, there is no fat! I opted to make another 729C and position the hole at min edge distance rather than central as per the plans. in this photo you can see where the hole would have been originally.
IMG_0589 by
Ed Fleming, on Flickr
And now for the really big mistake! The plans show two optional 5/8 holes through the bulkhead, one for the manual trim cable, the other for optional wiring. Since I am fitting manual trim at least one hole is non optional, and I opted to drill the other as well. Looking carefully at the plans, even if the hole is positioned perfectly, it will still result in less than min edge distance on all surrounding holes. Since this is per plans, it must be ok, but it seems important to get the hole position right so edge distance is shared equally.
It was at this point that I got too clever. I had read a number of build logs where guys had made a nice hole through 706B, only to lament that they now had to make corresponding cutouts in several other parts. Wouldn't it have been easier to have them all clecoed together and drilled in one go, they all wondered? Well thanks to the heads up, I was now ahead, or so I thought!
The problem is, when everything is clecoed together, there is no way to get the whole contraption into a drill press for nice accurate drilling, so I drilled a pilot hole, then went at it free hand. I did not pay attention to how things were going and it was a couple of minutes after finishing that I noticed to my horror that the hole was way off from where it should have been! The underlying parts, 730 and 729, whose edges bisect the hole, had cause the unibit to walk sideways and I had not noticed.
This is not good.
IMG_0593 by
Ed Fleming, on Flickr
If I lived in the US, I would have been online ordering new parts, but that is a bit pricey for me. initially I used my dremel to open the hole out to where it should have been, then I went ahead and made the other hole with a lot more care. But the edge distance is still really bad on some of these holes.
IMG_0597 by
Ed Fleming, on Flickr
So the email went off to vans, could I save this part, or were Fedex going to make some money out of me?