Today was a great day in the shop. I got a ton done. First off I drilled the other two holes in the Z-brackets. First I used a scrap screw/washer/nut to hold it down in the center. Then I squared the bracket to the spar, then drilled the other holes. Instead of using a 3/8" cleco, I used a bolt instead. I found that when I did the tie down brackets, then a cleco will move on you, which can mean you have to redrill the hole to get it right. With the bolt in there, this thing is solid.
With all of the brackets drilled, I temporarily put them on with clecoes. I used bolts just to drop though the other hole because I didn't have enough 3/8" clecoes.
Then for fun, I put tank skin and baffle into the wing to see how the allignment was.
Root alignment was very very good. Perfect, actually. I marked where the holes were on the root z-bracket.
Then I took the skin off and marked where the holes were on all of the Z-brackets. I did all of this not knowing if my alignment was off. I didn't want to spend the rest of the day blindly putting all the effort into putting nutplates on and all that just to find that I have edge distance issues.
The root rivet line was right in the middle.
All the others were nicely offset towards the edge of the flange, allowing excellent pop rivet gun access from behind.
Next I tapped out 3 nutplates and screwed them down to the brackets with scrap screws and drilled the nutplate rivet holes.... don't do this to the root (inboard) z-bracket, as the nutplates go on the spar.
Then I countersunk all of the holes so the rivets sit flush against the spar.
These are the nutplate holes on the spar for the root bracket.
I was able to countersink 4/6 holes with the cage. The other two were done freehanded. No big deal with the cordless drill. I would be scared to do this with the air drill.
Then I primed the one flangle of the Z-brackets that sits against the nutplates.
And while I had some primer out, I dabbed it on the countersunk holes on the spar.
Riveting the nutplates onto the spar was another chore. I tried using the mushroom set, but it just wasn't working. I drilled out one rivet then decided to just use the backrivet set carefully. It did scratch the spar ever so slightly. This pic really throws it out of perspecting. In retrospect, I should of put some tape over the backrivet set.
The shop heads turned out great.
And the weapon of choice.
Next was riveting all of the nutplates on.
Then temporarily screwing them each onto the spar with 2 screws.
Damn, this picture didn't get what I wanted it to. There were thousands of gnats flying around the lights today. I have never seen so many. I had thousands of them dead on the floor around the shop. I don't know how they killed themselves on a flourescent light. Not like they are hot.
Next I clecoed up the tank. What a pain.
Then I put the tank onto the spar. Things are looking BIG!
I took a pic of the inside to see how my alignment with the z-brackets were. Looks good.
This is a SWEET setup. There was tiny tiny tiny gap between the tank and leading edge skins. So small that I couldn't even get the ruler through it. Definitely less than 1/64". I wasn't going to mess with it, because that would of made it worse.
This is the inboard (root) edge of the tank.
First step is to drill out the holes in the root z-bracket.
Next the leading edge came off CAREFULLY. I didn't wans to screw up the alignment.
Using the same trick as the root, I drilled out these holes.
Then the tank skin came off. This gives me access to drill out the remaining baffle to z-bracket holes.
Finally done with the Z-Brackets!
Next on the list was to drill the #19 screw hole that attatch the leading edge to the tank. I clecoed the outboard-most z-bracket to the tank. Then I put the tank back onto the wing, clecoing the root of it to the z-bracket, and screwing the outboard z-bracket to the spar. It was some work, but it guarenteed alighment.
Then I drilled the #19 holes. I was stupid and did this in one foul swoop. I should of walked them up slowly to final size. It didn't cause any harm, but it wasnt smart.
Finally, I took all of the z-brackets off the spar and clecoed them to the baffle in order to match drill the tank.
Last Modified: August 13, 2023