Replace AN525-10R12 w/ AN525-416R12 on F25?

[mattputz]

Question RE F25: my two lower splice plates ended up having very slightly oversized bolt holes because of a wobble in the drill I was using. (I've since switched that out.) I'd like to simply replace the AN525-10R12 (3/16) hardware with AN525-416R12 (1/4) hardware for those, but I have no idea if this is structurally appropriate. Anybody care to take a swing?

Matt, Sonex 1585

[Bryan Cotton]

Matt,
Does the 1/4" hardware have a 2D edge distance? If so that makes for an easy yes answer.

[peter anson]

The splice plates are only 3/4 " wide so the edge distance is 3/8" or 2D with the standard 3/16 screws. One option would be to fit Hi-Lok fasteners. You'll just about fry your brain working out the correct part number to buy but they are available in 1/64" and 1/32" oversize so you'll be close to maintaining the 2D edge distance. You will also need to buy a suitable size reamer.

Peter

[mattputz]

Thanks for this guys - I'm just back into building this year after a two-year hiatus - is the factory still taking these kinds of questions?

[Sonex1517]

Thanks for this guys - I'm just back into building this year after a two-year hiatus - is the factory still taking these kinds of questions?

Sonex technical support should always be your first point of contact for this stuff.

Of course, you may hear they have never heard of the problem before, but....

[kevinh]

Thanks for this guys - I'm just back into building this year after a two-year hiatus - is the factory still taking these kinds of questions?

Yes. It might be they recommend a longer or fatter piece as a fix.

[N265DF]

Wouldn't take a very large piece of 3/16" 6061 T6 to make that piece. But if you don't have the material... I recall making it a couple of times because I thought I bent it too much. Thought I would weaken it if I rebent it. Talk about overkill.
Darrell Frey #265

[mattputz]

I'm not really concerned about rebuilding the splice plates - that's easy - I'm concerned that I've already drilled the longeron they mate to (along with all of the rivet holes and skin fitting and whatnot) and don't want to redo that completely if I don't have to...

This is all helpful - I'll shoot Sonex an email and see if they have any additional wisdom. Happy to get more here as well - thanks, everybody...

Matt

[N265DF]

Aircraft Spruce has aluminum tubing 1/4" od x 0.18" id for $1.45ft. the o.18 could be reemed out to 0.1875 (3/16). A bit ticklish to cut and file to 1/8 In thick-these as bushings for the longerons. Then make splice plates w/3/16 in holes. Spruce also has brass tubing 1/4" od X 3/16" id for $1.78/ft. Sonex will probably have a real easy to implement answer.
Darrell