One of the mods I decided to do on the baggage area was to install a set of cargo tiedowns. I had these in the Maule M7 I owned years ago and thought they would be a handy and inexpensive addition.
Now I don’t have plans to haul an entire basecamp worth of outdoor gear, but I can foresee loading up loose or awkward cargo and wanting a way to keep it secured in the event of turbulence. Therefore, I wanted a solution that was unobtrusive yet available when needed.
I asked the Facebook RV-10 community for their thoughts and a couple replied with pointers to single L-track anchor rings like these:
One builder even nicely incorporated them into his interior carpeting:
The tiedowns are sturdy and low-profile and that allow for the removal of the tiedowns when not needed, either by removing the spring-loaded ring assembly or unscrewing the base. They are designed for automobiles and come with a backing plate, screws, and locknuts. Since these are going to be in the baggage area and I won’t be able to access under the floor, I decided to replace the locknuts with K1000-4 nut plates.
I spent a fair amount of time figuring out where in the baggage area to mount them. I wanted them laid out in a rectangular pattern as close to the far corners of the baggage area as possible. I quickly realized that the step mount access panels would be an issue, since they occupy the forward corners. I considered placing the tiedowns inboard of the access panels, to maximize the fore-to-aft spacing but this created a trapezoid pattern instead of a rectangle. In the end I decided to shift the tiedowns aft and outboard. This reduced the fore-to-aft spacing but gave me the rectangular pattern I was looking for.
I then needed to locate and fabricate some doublers. I used some scrap .063 to create four plates slightly larger than the tiedowns themselves. The doublers are trapezoidal to account for the angle row of rivet holes in the floor. (See below for a size reference.) Fortunately, the angles are symmetrical so once I had one doubler cut to size it was simple to cut three more. (I was also able to match drill them as a set.)
I rough-fit the doublers with the floors clecoed in place to avoid interfering with the baggage floor ribs. These fit well, except for the aft port side one, which sits underneath the F-1027 close-out panel. I ended up drilling two extra holes to receive blind rivets front the close-out panel when it comes time to rivet that in place. (I had already skipped ahead in the plans and match drilled the rivet holes in the baggage floors.) I also trimmed the edges to eliminate interference with the rivet heads. See if you can pick out the extra holes in the image down below.
I also needed to sort out the orientation of the rivet holes in the nut plates. There is a lot going on in such a small area, but I was able to find an arrangement that will spread any stress forces while not interfering with existing structure. I oriented the holes in the tiedowns diagonally, so they aligned with those in the opposite corner. I reasoned this would provide for the greatest tensile strength when cargo was secured.
I marked out rivet and screw hole locations and drilled, deburred, dimpled, countersunk, and primed everything, taking extra care to keep straight the left/right and up/down orientations.
After the primer was dry, I set about riveting the cargo tiedowns in place. I started with the nut plates but quickly realized that I misaligned the screw and rivet holes, causing interference with the screws. Fortunately, I trial fit the screws on the first piece and so only had to drill out a few rivets. I enlarged the 1/4″ holes in the doubles and floors (although 2 sets of holes were just fine as-is) using a size N bit and deburred them. From there the riveting went quickly and I was able to attach the tiedown bases using the supplied stainless-steel screws.
Build Date(s): 11-Feb-23 to 12-Feb-23 Build Time: 4 hours