SonexBuilders.net

Sonex 1243 Formers..........

Ken........the comment about using shims between the formers and the turtle decks skins is exactly correct. I have an early Onex....kit 0024.....and those formers were terrible. Almost all the rivets on my Onex have shims to take up the space......from .016 all the way up to .187....! I understand the later kits were better in that regard. If I had riveted the turtle deck skins with out the shims it would have been a disaster.

It will be slow going to fit and fiddle with all those shims but be patient and do it right and it will pay off. This is a highly visible area on these airplanes so don't rush this part of the build.

Gordon........Onex......Hummel 2400

I had seen a lot on the forum about the shimming.
Looks like the formers journey starts with the #5 former that was real tight due to the scallop radius's sticking out. A short session with the scotch brite wheel to blend them down. Next up is the edge distance in the top tabs from the lasered skin holes. Area 51 mentioned that this was coming.. If it gets too bad, I'll order another one!


left and right red dots from skin holes.

Ken...........

I, too, thought maybe I had gotten the "runt of the litter" so I ordered a replacement. It was the same. I had high hopes because the picture on the order site shows the former with flutes. That's how I became aware there were two different formers out there.

For the record..........I didn't have to use any shims between the formers and turtledeck to get an acceptable (for me) fit. Just make sure the former flange matches the angle of the skin and push it tight. Very little unauthorized dimpling of the skin.

After some more tweaking, the #5 will be fine. All the rest have now been piloted and I am happy with all the former placements. It took a lot of patience, but surprisingly, I don't plan on shimming anything because the formers fit nice and tight against the skin. The only adjusting I did was slightly open up the former flange / flutes and that allowed them to fit nice and snug against the skin without gaps.

I see why Sonex went to the scallops on the #5 (possibly all formers) because removing the flutes allows you to tweak the flange like an individual tab without distorting the piece. This theory worked for me as my #4 left was somewhat distorted after trying to adjust flutes to bring the flanges up to the skin, this seemed to distort the former, so with nothing to lose I cut out the flutes, tweaked the tabs and it snugged right up to the skin.

A lot has happened rather quickly it seems. Finished the aft fuse box assembly and turtle deck installation. I removed the #1 formers since I decided to paint them at the last minute. All that remains is torquing up the cross tie box hardware and riveting it shut for good. I'll install the formers once the paint is cured.


Very little dimpling of the turtle deck skin, I'm happy with it!

Hopefully the forward end goes fairly quick, the sides are already made along with the firewall assemblies.

Reinstalled the painted formers and finished riveting. The aft fuselage tail cone assembly is finished.

Rearranged the garage again as I needed more room for the front half build.

A little weary of the sawhorse setup, it feels nice and steady though

Very nice Ken! I did the same thing with the saw horses.

Haven't posted in a while, but, I have been steadily chipping away at plans page SNX-F11 forward fuselage and also SNX-F09. Everything has been piloted and subsequently up sized for riveting and AN hardware installation. All that remains are a few splice plates that need to be upsized for hardware installation, I seem to have a very slight gap in the lower splice plate ends, not sure if it is something to fret about since the aft sides are butted up nicely.

Also assembled most of plans page F09 and clecod it all in for a glimpse at what is ahead in tweaking etc.

SNX-F11 pretty much done except for some splice plates


SNX-F09 clecod in from the outside


SNX-F09 from the inside



Looks like a week delay is in order as I have to travel to TX for a week due to work requirements.

Good progress Ken, I like that shiny finish!

Thanks Darick;
I envy your build, very nice work. Some day I hope to be finished with mine!

I have encountered a minor set back in my splice plates, the lower ones ended up with a small gap in the forward ends somehow. I suspect they moved slightly while up-sizing since some remain clecod in during the aft fuse construction. Sonex recommends closing them up by replacing one vertical since it is already up sized and re-positioning the other ends before up sizing. Everything is now bolted in place to prevent future movement. Ordered two just in case.