Thursday, February 9, 2017

Tail complete, less tips

Yahooooo!
Tail is complete less tips.
The elevators were assembled onto the horizontal stabilizer with no issues. Remember the horizontal stabilizer  is the first thing to be built. It is sure obvious to me that building the tail feathers taught me a lot about building. I am glad I started with the tail as per Van's recommendations. There is definitely a learning curve to this. here is a shot of the completed tail, taken from far enough away to hide my lessons learned. No seriously, the elevator was inspected by a tech counselor, so no worries, all is good. But it is going to be a painted airplane, no polished aluminum for me.

The elevator attach was easy. Everything was square and true. I only had to screw in one heim joint 1/2 turn to make both sides even within 0.010". It is quite amazing how close everything lined up. What an amazing kit.
Now to find a place to store it. And start the wings.

Lessons Learned:
1) Use proseal on the trialing edges. I use the T88 epoxy on the elevators to try and keep the skins from separating. All this did was make a mess to clean up; the epoxy squeezed out and cured onto the outer surface of the aluminum skins, and was a bear to clean off. The proseal clean up was much easier.
2) Instead, use the wood block that was built during the practice kits to break the skin's edge to prevent the edges from separating during the trailing edge gluing/riveting.
3) For the trailing edge rivets, don't use the back rivet set for the final setting of the rivets, it is better to use the rivet set with a hole in it and a the 1/4" diameter flat rivet die used for squeezing the -3 rivets. The reason is the back rivet set is slightly concave, whereas the flush set is flat with rounded edges.
4) The use of a double offset -4 set for the tip ribs to spar is a necessity. This lesson cost me a new tip rib.
5) Without a tungsten bucking bar, the skin to elevator spar rivets would have been nearly impossible. The extra mass and small size is really needed.

Finishing Elevator

The left elevator was finished as expected with no issues, except for some reason, the elevator skin to the rear spar had a gap once everything was assembled; probably no more than 0.002", so most likely within spec without being touched. So as I riveted the spar to skin to hinge, I would use the squeezer to re dimple the whole structure, then set the rivet, then move on to the next hole. This was more annoying than anything else.
Moving on to final elevator assembly.