Tunnel to belly pan transition (again)

[Pbruce]

I have the belly panel and tunnel nut-plated in place. The tunnel has flanges pre-bent into the outer edges for attaching the bottom edges of the boot cowl sides. Mine are sticking out at the back though, proud of the belly pan a fair bit (3/8”). I’m seeking advice on how to “flatten” or otherwise finish this area. I’m a novice metal worker so I need a simple solution.

Also, I think Lee said he didn’t even attach the boot sides to the lower longerons. Im wondering what others did? Sharp 1” radius bends around the longerons and then attach sheet metal to the tabs on the longerons , or large radius bend and only attach to the tunnel or what?

Thanks in advance.

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[podo]

Pbruce, I'm doing the same as Mark's Patrol shown in these pics from OSH this year. It seems fairly elegant and not hard to achieve. I bent my tunnel lip to match the angle of the former then wrapped the aluminum around the lower longeron and attached directly to the tunnel with machine screws, bypassing the longeron tabs. Those tabs did not align very well to the tunnel. I made a bend with a hand seamer to the corner of the boot cowl to cover the gap just as shown in these pics.
Pete

[Pbruce]

Hey thanks Pete. That actually looks pretty good! Man, sometimes the best solutions are the simplest ones, begging the question: why didn’t I think of that? I was getting ready to cut the bent flange off the sides of the tunnel, and rivet a new piece of angle on at the correct depth. Lotsa work! Thanks also for the point-out on handling the bend around the lower longeron. If you don’t mind responding again, did you anchor the boot sides to that longeron at all, or just let them float?

[davzLSA]

Hey Bruce I ran into the same situation and handled it pretty much the same way you did. I think they are bent unevenly at the factory. But we cant let perfection paralysis stop the building process.

[Pbruce]

Indeed. Doesn’t need to be perfect; just trying to move on. I asked Mark G and if I read him right, he thought this needed to be fixed up, but my pics and description weren’t good enough for him to prescribe a particular solution. Thanks again to Pete and you for this idea. Perhaps it will work. I just never thought of it. If there are other ideas, I’m all ears (and eyes).

[Lee]

Hi Pat. I made a carboard template of the boot cowl first to test the fit. Learned a LOT while fitting the carboard. I bought a roll of floor protecting material at the local Home Desperate store that worked beautifully. Got lots left if anybody is close and wants some. Also cut a couple of 3/4" x 3/4" pine sticks and ran them from the fire wall to the former to support the carboard. Just taped them in. Turns out that the bends on the boot cowl forward and aft of the landing gear mount are totally different. Trial and error was way cheaper and easier to fix with the cardboard than with aluminum... I hand formed the aluminum around a 2 1/2" pipe and sometimes a 1 1/4" pipe until it fit just right with no clamps. Like so many building tasks, once I got going it really wasn't too hard and just kind of fell into place.

[Pbruce]

Thanks. Pictures are very helpful.