2.0 Hours -
With the F-704 bulkhead more or less finished, it’s time to move on to the F-705 bulkhead. Right away, this one starts off with some fabrication. After finding the right parts and stock material, I had to cut the F-705B center section bar to length, cut the F-705C bar doublers to length, and make the F-705H spacers.
The F-705B center section bar was fairly simply. I only had to cut one end in order to make it the correct length, and then draw a line down the center of one side. Using the line, I positioned the bar on the F-705A rear spar attach bulkhead, and drilled the bar to the bulkhead using the holes in the bulkhead as a guide.
The F-705B center section bar has a line drawn down the center that is used to align it with F-705A for drilling.
I thought the F-705C doubler bars were going to be more complicated since they have a couple of bends in them. However, after finding the parts, I was happy to see that the factory already made those bends for me. With the bends already made, all I had to do was use the dimensions given on the plans to figure out where to cut the bars to make them the correct length. Once cut, I lined the bars up on the F-705B center section bar and match-drilled the doublers to the bar.
The F-705C bar doublers are bent at the factory, but they still need to be shortened on one end and tapered on the other.
Finally, I made the F-705H spacers. These small spacers will go between the F-705B bar and the F-705C doublers. The plans give the dimensions for the spacers, and, for the first time that I’ve seen, the plans specifically mention which direction the grain of the aluminum should be in the finished part. If Van’s takes the time to mention it here, it must be important. After making the spacers, I clamped them into place and drilled them to the bar and doublers.
The F-705H spacers are made from some bar stock. This is the only time I've seen the plans reference grain direction, so it must be important.
A completed F-705H spacer. The camera makes the small notch hard to see.
The center section bar, bar doubler, and spacer all aligned for drilling.
After drilling all the parts together, I tapered the end of the F-705C bar doublers.
Up next, I will drill the seat belt anchors to the F-705 assembly. However, I decided to call it a day at this point.
