Main gear install, part 1

It’s another one of those nights…I came into this one expecting to spend maybe a couple hours total in the shop and finish the evening with an airplane sitting on actual gear legs. It didn’t quite go like that, but not in any sort of horrible way or anything, just the usual unexpected stuff cropping up.

The first step was to get the inboard and outboard wear plates installed. These bolt up to the bottom of the fuselage, in assembly with the longerons (outboard) or gear element (inboard), and are the upper surface on which the gear leg rests. This is also a two-person job, since it requires one person outside holding the bolts while the other is reaching inside and tightening the nuts. No big deal once I recruited Josie’s help, though.

At this point, I thought I was ready for the fun part, to the extent that I went ahead and lifted the forward fuselage up nice and high using my engine hoist attached to the engine mount. Then, once I had it up nice and high…I remembered I needed to insert the outboard bracket bolts from inside the fuselage first. Well, I didn’t need to necessarily, but why not go ahead and get that done now? As it would turn out, it was a good thing I didn’t skip this.

This is a point where I’m diverging from the plans. These outboard bracket bolts are a very critical part of the gear mount, and their installation requires actually torquing them to a fairly low value, so as to not deform the outboard brackets. They also require periodic retorquing to ensure proper clamping of the gear leg. The plans call for all of these bolts to be inserted from below, and nuts installed above – which leads to many RV-8 owners providing horror stories of figuring out contortions to get a torque wrench inside the crowded gear towers each year at annual.

One way to avoid this is to simply reverse the bolts and inserting them from above, allowing the nuts to be torqued from below. The problem is, the bolts still need to be kept from turning at this time, so you’d still need to get inside the towers. For this, someone came up with a novel solution, namely little steel C-channel clips that slip over the bolt heads and then engage the weldment or a nearby nut inside the element to hold the bolts. I bought a set of these clips some time ago.

Anyway, after lowering the fuselage again, I got to work trying to install the bolts along with the clips, and quickly ran into issues. At first I’d fitted the clips to the bolts before hand, but I could see that they’d be interfering with other nuts while driving the bolt in. Whoops, guess I’ll have to lay the clips down in the channel and then slide the bolts into them. Except I couldn’t get any of the clips to line up with the holes – at their size, they all interfere to some degree (some worse than others) with the surrounding nuts and/or structure.

Bottom line, there’s no way these clips will work as provided. The question now is, do I modify the clips to fit properly, or just ditch them entirely and go back to the factory setup? That’s not a decision I want to make off the cuff, so I quit for the evening and retired inside to do some reading and thinking.

Update: Well, I don’t feel so bad about tonight. Found a build log I’d looked at previously for the bolt clip info, and now I see a couple relevant details: First, he specifically mentioned needing to modify the clips to fit. Second, he says he spent five hours modifying the clips and getting the bolts slipped into place. Here’s hoping I don’t need quite that much time…

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