Installing floor panels to the fuselage frame. ![[Floor Panels-20241102194437999.jpg]] Five separate, slightly overlapping aluminum panels (.032” 2024T3 Alclad) make up the floor. They are very thin and light but gain good strength from being attached to numerous fuselage tabs. ![[Floor Panels-20241102194527617.jpg]] Before they can be match-drilled and installed a proper fit is required. The first question that arises is in what order they should overlap. Some overlaps are determined by how they are sized in the overlap area. The other consideration is how to best give access to the bottom fuselage. Being able to lift alternating panels quickly allows for fairly quick access underneath. ![[Floor Panels-20241102194635692.jpg]] The next step is to shape the panels in all their detail. This requires many iteration with a lot panel edge fuselage contact. Initially I used tape on the panel edges to protect the fuselage paint. On second though I realized this does not solve the issue when the airplane is in use. A better solution is to excessively round the edges (chamfer with 100 grit sand paper, then smooth with 600 grit). ![[Floor Panels-20241102194737282.jpg]] I found a metal shear and a good set of files, both small and large to be indispensable for shaping the panels. Once I was happy with the fit I taped the panels in place and started match-drilling. On each tab I marked the center, center-punched, and drilled pilot holes (#40 drill bit) bottom up. A second **12” long #40 drill bit** was necessary to reach all tabs properly. Each hole I immediately arrested with silver Clecos. ## Nutplates and Countersunk Screws Nutplates are not strictly necessary for installing the floor panels but they work well. Thread clips (Tinnermans) or simply pop-rivets are both less laborious options. I really liked nutplates from the beginning and did not mind the extra work. I also optimize for easy maintenance. ![[Floor Panels-20241102194816976.jpg]] After assuring all the holes are still aligned I drilled the final hole size (#27 drill bit) top down. Either a small drill or a long bit is necessary to reach all holes. I lifted the panels and deburred all the new holes. The tab I also deburred roughly (will be countersunk later). The Avery line of tools are super useful for this kind of work. I used a jig and a dampening spring on a #40 drill bit. This jig is very fun to use. Again the long 12” #40 was absolutely indispensable. ![[Floor Panels-20241102195121450.jpg]] Similarly for countersinking the rivet holes I needed an extension. For this I used the screw on extension of the deburring tool. It’s not designed to be used in a chuck but worked well enough. ![[Floor Panels-20241228131250232.webp]] The riveting tool needs to be aligned at the top of the rivet and the gab between nutplate and tab should be kept to a minimum while squeezing. ![[Floor Panels-20241102195306905.jpg]] Finally I countersunk the center hole of the tabs and dimpled the floor panels. This allowed me to use the same countersunk screws as everywhere else. The dimple sitting in depression also increases the strength of the connection. ![[Floor Panels-20241102195400099.jpg]] ![[Floor Panels-20241102195412347.jpg]] This concludes the phase one of the floor panels. Later they need all kinds of modification for fuel lines, brake system lines, aileron servo, and more. The good part is they are easy to remove.