Luis & Fab's RV-7A Construction Log

These two brackets start out as 3/16″ aluminum angle.  Once they are cut the right length, they are match drilled to the top of the F-705 bulkhead.

After screwing one of these up, here is the correct procedure to match drill these angles.

• Clamp the angle to the F-705F channel as shown below, but only drill the holes on the forward side of F-705F! (i.e., the holes facing up on the picture below)

• Now insert the F-705D side channel and the F-705E doubler between the F-705F channel and the F-705G angle.  Cleco and clamp everything in place, and match drill the holes on the top side of the F-705F channel (the holes on the right face of the channel in the picture below)

The result is a bunch of nice holes.   If you forget to insert the side channel/doubler, you end up with misaligned holes on the top face of the angle (on the right if you look at the picture below).  At the same time, it is very cumbersome to try to align the top channel, side channel, doubler and angle all at once with no holes on the angle.

Finally, once all the holes are match drilled, you can cleco the angle and draw where the oval slot should be.  I started the slot by drilling two holes, and then used a dremel tool to give it the final shape.

The seat backs have a clever two-position adjustment mechanism.  The top of the F-705 bulkhead has two slots.  A tab that holds the seat back can be adjusted to one of the two positions depending on how much you want to lean back.

The first part of making this part of the bulkhead was to put a very slight bend on the two F-705K aluminum strips that act as guides.  This was a good excuse to buy a little bending brake from Harbor freight.  It is as simple as it gets, so I figured this one thing from Harbor Freight would be OK :-).

I clamped the F-705K aluminum strip in place, and started cranking on the brake.  Just a little at a time to get the right bend angle.

Here is a closeup of the F-705K after the bend was complete.

The next step was to take the F-705L shim and match drill it to the top of the bulkhead.

Then came the tricky part.  The F-705J angle has to be drilled to the side of the bulkhead, but has to sit 1/8″ from the top surface (refer to the drawing at the top of the post).   I used some 1/8″ angle as shown below just to the set the right distance.  After the F-705J was drilled and clecoed in place, I simply pulled out the 1/8″ angle.

Finally, here are two shots of the entire assembly clecloed together.

After taking the tailcone apart prior to priming, I decided it was a good time to dimple the hole used to hold the rudder cable guide.