Sun Jan 27 2008

F-704 Spar center section

These photos are actually from late last night. I laid out the location of some more snap bushings on the web of the center bulkhead.

Fortunately, before drilling I double checked the plans. I had marked the hole locations on the wrong side. Whups.

All set for snap bushings now.

Then it was time to clamp up the spacer block using a couple bolts to get the alignment right.

Some quick work with the drill...

...and a little countersinking and these are ready to be riveted on.

Then I tapped in a couple of the close tolerance bolts and match drilled the vertical members to the center sections.

Next was to clamp everything up in preparation for counter sinking the nutplates.

Note the tape to prevent chips from getting down in between the channel and the bars.

Then on to squaring the control bracket mounts.

So I could match drill them from the back side.

I went on to install the nutplates on the center section. Using one cleco and a screw to ensure the nutplate is in the correct position.

Update: Don't install these nutplates yet! You'll just end up drilling them back out when it comes time to fit the gear leg weldments. Go ahead and drill and countersink for the nutplates, but save yourself some hassle and wait until later to install them.

Squeeze the first rivet....

...remove the cleco and squeeze the second rivet.

Then it was time to cut the stiffeners for the forward bulkhead.

I match drilled them to the web of the bulkhead, but dang if I didn't use the wrong bit for the screw holes. I was supposed to use a #19 bit for a #8 screw, but I grabbed my #11 bit which sized the holes for a #10 bolt. Crap. Oh well, it'll be fine. I checked and there's plenty of clearance for the bolt head.

Then it was time to rivet the vertical members on to the center section bulkhead. I inserted all the rivets and placed riveting tape over them so they wouldn't fall out.

I got this idea from Dan Checkoway's site. Thanks, Dan! The back riveting goes really well.

I had to stop because the noise was keeping Kerin awake, but I did get this one side done. Both the manufactured heads and shop heads look pretty much perfect.