Fwd ribs, Bulkheads, & bottom skins

Total Hours: 1119.2 hours
Fwd ribs, Bulkheads, & bottom skins: 66.7 hours

rv10 forward and mid fuse joined
forward and mid fuse joined

This was section 28 in the plans. It felt like I would never finish this section. Most notably in this section the forward and mid sections of the fuse are joined. I was going to use hardware store bolts to join the spars, but in the end decided to use the close tolerance bolts provided in the kit. I felt this would better insure I had proper alignment between the sections. The worry is that there may be trouble removing them when the time comes to join the wings and the bolts get damaged. I don’t think this is worth the concern. If the cadmium coating of the bolts is entirely scraped off, I’ll replace the bolts when it’s time for the wings. But I doubt that will be necessary. I only torqued the smaller bolts (AN6) , leaving the larger ones (AN9) in place to help with alignment but without nuts. And I will definitely use fresh nuts on the smaller bolts when I join the wings.

RV10 Forward section ready for joining
Forward section ready for joining
RV10 Mid section ready for joining
Mid section ready for joining
RV10 spars joined with spacers
spars joined with spacers

 

I did have a few relatively minor issues during this section which added up to a whole lot of extra time. One was having to drill out a bunch of rivets to allow clearance for the front floors. In the process I damaged one hole really good which will now require a 5/32 rivet. Another issue was when riveting the firewall to one of the forward skins. Somehow the dimple in the rib cracked. In a very tight spot I managed to polish out the whole cracked dimple and install a doubler plate. Here’s a few pics of the repair, which required a 5/32 rivet. (I have a supply of AN426AD5-12 rivets which I can cut to size).

Front side repair (AN5 rivet)
Front side repair (5/32 rivet)
forward rib repair
forward rib repair
forward rib repair
forward rib repair

The last issue I dealt with took the most time to figure out. The plans have you install the gear mounts with just a few bolts in order to get a bunch of holes matched to the mounts. No problem on the right side, but the left would simply not go in. There was no way I could get the bolts all in. Somehow, it seemed that the alignment (which seemed perfect when I matched them to the spar) was off. In the end I realized that the mount was slightly warped (just a little curve to it). When I matched it to the spar, it was clamped down tightly to the spar which caused the curve to flatten out (as it should). But now as I try to install it, there are no clamps and the holes don’t align. After many, many, many hours of thinking and trying lots of things, I came upon the solution. I mounted an AN3 bolt to my drill press and used it like a lathe. I then filed out the threads of the bolt entirely and brought the end to a point. I then used a scotch-brite wheel to round out the tip. I used this as a guide pin to get the mount into alignment. I positioned the mount so that one hole was aligned and put in a bolt. Then I used my guide pin (oiled up real good) to force alignment with another hole. This allowed me to insert a second bolt. When I removed the alignment pin, all the holes were aligned and I could finally proceed with the task. This all took a good 8 hours to figure out and get working. Next time something like this comes up, it’s not going to take so long.

homemade AN3 guide pin
homemade AN3 guide pin
RV10 Right gear mount
Right gear mount after bolts removed

 

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