Today I wanted to wrap up prepping the F-704 center section and move on the F-705 bulkhead assembly.

Before I started riveting the center section (horizontal & vertical) together, I needed to match drill #30 holes in the center section vertical bars (F-704G) to the center section.  Have you noticed that everything is called "center section"?  As thick as the vertical bars are, I was concerned that I would end up drilling those holes at an angle which would make it hard to set a AN426 rivet.  As it turned out, I got all 4 holes straight and they came out fine.

Next, I moved on to rivet the F-704C's and F-704D's to their respective center sections.  What I found worked the best here was to use the c-frame to set the rivets.  A couple of 2" x 4"s served to hold the center section level with respect to the c-frame.

Once I got the center section properly positioned, I WHACKED the c-frame with a hammer.  This worked pretty well.  I actually had quite a little control over setting the rivets with a hammer.

Once I set all the rivets with the c-frame, I went back to set the flush rivets that attach the center section vertical bars to the center section.  I had previously countersunk the vertical bars to accept the flush AN426AD4-14 rivets.  I ended up setting those rivets with the c-frame as well.  I just put a flush rivet set in the c-frame, positioned the center section, and WHACKED it with a hammer again.  The -14 rivets were the longest rivets I have and they are still short.  From what I can tell, they do not perform a structural function.  They just hold the vertical bar in place while you attach the wings to the fuselage.

This was the forward center section.  Looks like a serious structure when you start to put all those rivets in.

While I was working on the center section, I installed the 18 or so nutplates.  That only took a few minutes.

Completing what I wanted to work on with the center section, I moved on to the F-705.  It probably took me over  an hour to locate the majority of the parts for the F-705.  I spent another two hours removing vinyl and deburring parts.  No exciting pictures to be had there.

One of the first parts I fabricated on the F-705 was the F-605C doubler.  You have to taper the doubler down to a rounded point with a 1/4" radius.  The print shows that the bar doubler is supposed to be 12 1/2" long.  Mine was actually almost 13" long.  I looked around various builders web sites and I didn't see anyone mention trimming this doubler so I left the length alone and marked the taper according to the print dimensions.

Ready to trim....

Cut, debur, file, debur some more, then repeat. After nearly an hour and a half, the bar doublers were transformed to look like like the drawing on the print.

The next fabrication task was to fabricate the F-705G- L/R angles since I am going with a tip-up canopy.  Now this seems like a simple task on the surface. I forecast another hour or two of cutting, deburring, filing, etc.

You have to make two of these angles and Van's instructions do not say to much about fabricating them, but reviewing the prints, I got the feeling that the two angles were NOT going to be the same.  For example, there is a 1/8" taper on the angle on the left side.  Van's makes reference that the "LEFT SHOWN".  Hmm, does that mean that the RIGHT one is different?  Looking at the print, it looks like the taper is to the outside of the F-705 on both the left and the right sides.  I am assuming that is because the fuselage is starting to taper aft of this bulkhead and the 1/8" is to make sure that it doesn't interfere with the fuselage skin.

The other thing that I noticed with fabricating the angle, is that this is being made out of AA6-187x2x2 1/2.  The print shows that the shorter flange is 1 3/4".  When lining up the angle on the F-705D Bulkhead Side Channel, it appears that if you leave the angle 2", that it will be pretty close to a row of rivets.  Trimming the angle to 1 3/4", it places that angle between the row of rivets on the F-705D.

UPDATE (12/25/07):  After fabricating my F-705G angles for a second time, you DO NOT need to trim the shorter flange of the angle to 1 3/4".  It will not interfere with any rivets in the F-705.  The only reason I can see to trim the angle to 1 3/4" would be for weight savings.

First F-705G (left side).  I have it marked on cut the angle to the 1 3/4".

You can see the difference in the angles.  The left one has been trimmed to the 1 3/4" and the one is just waiting for its turn at the band saw.

Hard to see here but, the left one has a taper on the left side and the right one has a taper on the right side.  This thick angle is time consuming to fabricate.  Two hours or so, and the F-705G's are cut out.

What a long day. I was busy all day and don't feel like I have a lot to show for it.  On the F-705, so far, there is a lot of time fabricating parts.