Day’s 54-56

Again, a busy few days.

We’ve had to do a lot of bouncing around on this project as we work out questions with Sling support. We found out that the lower motor mount brackets we had were the incorrect ones for our build. We also have a miss labeled seat support channel. They’ve let us know these will be express mailed to us directly.

In the meantime we riveted the lower firewall mounting support channel and ribs. (along with their rivnuts) We won’t be able to rivet the rest of the firewall on until we have the correct motor mount brackets because it’s too difficult to rivet them in place with the firewall mounted. But as shown before, we have Cleco’ed it on to insure everything else will fit.

We finished joining the side skins to the bottom skins. This took some work. At this point the skins are getting very tight and take some maneuvering to properly align. For example, with the rear section, it required one person pushing the floor skin down as the one running the rivet gun pushed up at the same time to get a flush joint. Because these ones were so tight, we added backup washers with 4.0mm rivets for extra strength.

With the forward floor the rear section was also quite tight in its tolerance. So to give it extra strength, the first 7 on each side we drilled out to 4.0mm rivets. The rest lined up perfectly and continued with the 3.8mm. We left out the front 4 on each side to give a little give when we get to mounting the firewall.

We were able to rivet in the top mounting channels for the rear torque control tube. This was with quite some effort. Having gone as far as we could with the floor supports and side skins while we waited for the pieces, it meant having to lean over the side rails in so awkward positions. As with the front tubes, it meant removing small amounts of material until a good fit was made and the tube rotated smoothly. Then because of the tight spaces, each 4.0mm rivet had to be hand pulled. After some patience and determination it turned out perfectly.

Lastly this week we started on mounting the long range fuel tanks to the wings. This had been put on hold as we were waiting for a pair of mounting brackets. These required anchor nuts that have to have countersinking done for flush rivets. Then proceeded to cleco the brackets on and set up on the wing to make sure everything aligns. Then riveted everything in place on the tanks. (Including the light bracket) We worked on the left side wing tank.

Next week we will mount it back on the wing and make sure the fuel lines are where we want them. Then we’ll rivet the mounting brackets on the backs of the tanks to the wing. This has to be done before the top skin is riveted in place, and the main tanks started.