HS ready for primer / VS almost complete
Wow, It has been a few days of non-stop building. The Thanksgiving holiday has been good for building. Current state is that the left and right horizontal stabilizers are ready for primer and final assembly (riveting). Today I started and nearly completed the vertical stabilizer. It has been pre-assembled, match drilled, and taken apart for deburring, dimpling, and primer prep.
On the horizontal stabilizer spars, I started off thinking that I would machine countersink in the drill press. I setup, went through all kinds of jigging and after the first two holes, decided that I didn’t have sufficient control over all of the c0mponents involved (cutter orientation, depth, part, etc.). So the spars came out of the drill press and I clamped them to a table and countersunk as shown in the picture. I liked this setup just fine. After the right stabilizer was done, it was time to “rinse and repeat” for the left one. By that time, I actually felt like I knew what I was doing and the other side went a little faster. Even though, this reinforces my plan to do both wing halves at the same time.
So, this morning I started the vertical stabilizer. This was a pretty quick (a full day and not quite done) part as there were so few parts. As with everything, all parts must first have all edges ground, filed, or sanded clean of tooling marks and scratches. The edges get smoothed. The edges of the part that might cut you if you ran your finger across it after grinding it smooth must be radiused. Then the flanges of the ribs are made perpendicular to the rib with seaming pliers. Then the ribs are straightened (skin holes aligned with a straight edge) with fluting pliers to shrink the metal. Yep, simple is relative, but most of this process (so far) is quite mundane and repetitive with a few moments being very careful and making careful decisions. With the Vertical stab, I find the first hints (or lack thereof) of things to come. These take the form of the instructions saying “Disassemble, de-burr, dimple, machine countersink and prime parts as desired.” This prompts you to make a wise decision as to whether to machine countersink or dimple the .032″ spars on the vertical stabilizer. I’m choosing to dimple. One of the first things that I did with the VS was to cut lightening holes in the spar doubler with a fly cutter in the drill press (no mention in the instructions and marked “optional” on the plans). It has been about 15 years since I’ve used a fly cutter. These things can be dangerous. I speak from experience. Luckily, with much care, the holes were cut without any parts going prematurely airborne.
I’m currently in the process of del-burring all of the drilled holes. Next the spars, skin, and ribs will be dimpled. With a little more prep, the vertical stabilizer will be ready for primer. I’m planning on doing a big batch of parts in my first primer batch. I’ll probably continue on and do the rudder and maybe the elevators, then priming all the parts at once. This would be all of the empennage kit. I’m sure that the primer process will take at least a week or so with this many parts to be prepared (note I’m doing a full process 0f wash, etch, alodine, prime).
This is the end of this holiday build marathon. It was great fun. We’ll see what kind of progress I make during the work week.
