DATE: 09-16-2025 – TIME: 2:08 – 4:15 ~ 2:20
I’m continuing on today with the top skin of the rear fuselage per drawings page SD75-FR-09 because my powder coated parts are delayed. I did, in the meantime, also reorganize the shop a little so I can get the fuselage crate out of the workshop and set up a lower bench or saw horses for the various sub-assembly into the fuselage.
There are some issues with the top skin SD75F2-1 that are weird. Of not much consequence is that the Solidworks drawings, and the printed drawings, show the diagonals SD75F20-2 and the SD75F20-4 with the rivets forward of the solid flange. These two angles are a far better fit, not obstructed by the longerons, if they are placed so that the solid flange is forward of the rivet holes, the same as the rest of the angles. I don’t see that turning them around could possibly be a structural problem but I have asked and am awaiting a response.
The description in the IPL files say to rivet from the front to back. I think they may also say to cleco from the front to back but whether they do or not, this is a good practice to keep the skins as flat against the longerons, and prevent puckering, as possible.
Meantime, I clecod all the angles and the longerons to the skins. There were also some A5 holes in the left rear of the skin aft of the SD75F20-7 lateral angle that are A4 in my left longeron C75F2-2. I drilled out the holes after removing the clecos I had already put in place and drilled out the holes without drilling through the skin so as to avoid impacting the holes in the skin which were the right size.
When riveting I always start at the front, rivet everything I can then pull the remaining clecos and go back and rivet from the front again.
The IPL instructions say to not rivet any A5 holes in front of the SD75F20-2 lateral. It looks like you can’t rivet any holes in front of the SD75F20-2 because of the lateral / baggage back that needs to be rivet there but the baggage back has a notch in that corner so it should be OK to rivet that last rivet in the longerons.
I did not get the skin completely assembled as I thought I would wait for Zenith to get back to me on the SD75F20-2 and -4 diagonals. If I don’t hear by the time I need to rivet them in place I will just rivet them the way that makes most sense to me with the solid flange ahead of the rivet holes.
