March 22, 2020
Now that all the horizontal and vertical stabilizer parts have cured for a day we’re ready to start assembling and riveting. It was a lovely day in the garage with a steady rain right outside the door.
All of the skins use flush rivets, which require a dimple in the skin and adjacent substructure. For the substructure, we used a tank dimple die to give just a bit oomph to make sure the dimples in the skin will nestle cleanly. Once we put the hand squeezer into the vice grip the dimpling process for the flanges went fairly quickly.
To dimple the skins we set up the DRDT-2 and accompanying shaggy table.
None of the dimpling is hard work, but it is a lot of holes between the three skins and all the ribs and spar. It was handy to have two people just to help move and set everything.
With all the dimples done, there wasn’t any more to do before riveting the rear spar together. Once we had the spars and stiffeners clecoed together we pulled out the pneumatic squeezer. We haven’t used this particular squeezer very much in our practice sessions, but now it’s our favorite way to drive rivets so far. It’s heavy – but once it’s set for the desired length it’s consistent, quiet, and awesome.
For all the rivets in the front spar, we had to drill out only one. The pneumatic squeezer slipped of one mid-squeeze and cracked the rivet head. Luckily it didn’t do any damage to the spar and the rivet was easy to drill out since it was already cracked. It was a good reminder to not be complacent, even when we’ve got everything set up well and a good rhythm going. The last step for the rear spar was to attach the hinge brackets and then we set it aside for a while.
The day was young so we started into the front spar next. The arrangement of parts on the front spar is so much more confusing that the rest of the empennage so far. It took us a while to convince ourselves which rivets were called out for which holes along with which holes to skip initially. Turns out we still drove 4 rivets we weren’t supposed to do yet and had to drill them out.
Overall, it was a productive day and tomorrow we’ll get to start on the ribs and skins.
Cheers,
-Kacy
(Total Build Hours: 54.0)