SonexBuilders.net

I am having a heck of a time getting my wing root doulber to fit right (I think thats the right name). This is the piece that you trim to fill the gap between your fusealage and the wing. No matter what I do I end up with a gap that bows out from the leading edge. I am scratch building so I don't have the factory laser cut holes that make everything line up perfectly. I am considering leaving it off and just putting a piece of rubber trim held on with 3m trim adehsive to cover the gap. I thought about making something out of fiberglass as well but don't really want to go that route after all the itching while doing the cowel. Has anyone done something similar? I looked at the factory planes at Oshkosh and all they had covering that gap was a piece of electrical tape (really). Thoughts?

Keith
#554

I used a black plastic flooring trim glued to the wing on my sonerai. It was flexible, but a bit stiffer than rubber. On the sonex, the rivets that fix the root rib may get in the way of where you want to glue.

If it were me making the doubler from scratch, I would start with a wide piece say 6 or 8 inches, wrap it around the wing and cleco. Mark with a sharpie on the wing where it sits. Also add station marks every inch or 2 on the wing and on the doubler and number both the same. Measure back from the sharpie line at each station on the wing to where you want to cut and transfer the cut distance to the doubler.

To measure the fuselage gap I used the rivet holes to measure to. Put the wings on the fuselage without the doubler, measured the distance from each root rib hole to the fuselage. Then subtracted the required gap and cut.

Steve 892

Van's carries a wing root rubber trim that works pretty good and looks great. Go to the Van's store and search for "rubber channel"

The problem with making the root doublers is one only us scratch builders face. The plans tell you to drill the holes in the wings, make the doublers without holes, and then match drill them to the wings. That works for most parts but since you can't easly drill from inside out once the wings are installed it gets pretty tough. I have been doing it with a combination of strap duplicators and using lexan templates. The problem is that if you don't get those holes exactly drilled perfectly any excess material either bows out at the front of the leading edge or if you don't have enough material it is too tight of a fit and won't go on. Maybe I can get some pictures posted to show the issue better. Trimming it to the fuealage isn't really a problem as that is the easy part.

I'll have to take a look at the black plastic floor trim the next time I am at the hardware store. I have looked at the vans stuff and that was my original plan but it is only supposed to work with a 3/16" max gap. I have up to about 1/2" gap between the wing and the fusalage without the doubler installed.

Keith
#554