The wing doesn't quite fit the fuselage. Can someone post some pictures of thier Super Kaos?

Thanks, Tim

Well, It is just a guess, but I'd say that the hole is too big or the wing is not wide enough.

Jamesf

Bridi designs typically have a rectangular piece of 1/16" ply that is glued to the rear center section on the bottom of the wing (prior to covering but I glassed the center section first).
It does two things, one is to provide a hard surface so as not to crush the balsa when tightening the wing bolts, and the second is to bridge the slight gap between trailing edge of the wing and the fuselage although that gap seems larger than normal.

I've built many Bridi low wing models over the past 25 years and I recall they all had something similar...

Rangerman - I take it you did not build this plane, right ? How did this happen ? If it fit's in the saddle, strip some of that covering off the wing and fuselage, set it up again. That wing looks to be glassed, it is enough to cover where the fuse set's. Providing everything fit's, this is an easy fix. After stripping, you can epoxy some hardwood back there, from the looks of things, fill the gap on the fuse side, then glass over it. Looks like no wing bolt's have been set up. Get the blocks in the fuselage, L&R, after you fix the area, drill in, tap 1/4-20, or epoxy in brass insert's. I would epoxy 1/8" plywood where the nylon bolt heads are going to sit, after all this, then re-cover. Something like the attached.

Crank

Ah, thanks guys.

Crankpin, it is indeed a hand-me-down. I explained that in the last thread but their server timed out and erased it and I didn't have the time to explain it all again.
I got the plane with the wings and fuselage covered. He did a great job except the trim on the wing is silver and the trim on the fuselage is black so this started me thinking I got the wrong wing but after I saw how well it fit I figured there must be a block, hatch, bulge or something missing.

I did have to cover the tail surfaces...see photos. The bad thing is Missle Red does not look like it should when it's 20 years old and you have to use a new roll to finish![:@]

I'm hoping to have it ready for the SPA event on the 26th (not a legal plane but they are making an exception since it won't be 'scored' per SPA yet), but we still are limited on engines so I thought I would try a OS 55 AX.

Tim,

judging from the fit of the wing on the fuse saddle, I'd say that the two were never quite mated in the construction process. Aside from the gap at the rear of the saddle behind the wing TE - which is quite an easy fix, the front fuse chin on the wing seems like it wasn't sanded to match the fuse bottom contour. More importantly though, the wing top at the front doesn't seem to mate properly with the front wing saddle.

My observation is not really a criticism but rather just something you might want to address when you strip the covering as Crank suggests. You'll be able to re-mate the wing to the fuse so the bolts are not subject to undue pressure caused by air entering the fuse at the saddle junction. The pressure applied to the screws is also commensurate with the mating of the two parts and if they don't mate well, you'll have high pressure points along the junction.

I'd make sure that the two parts mate well before mounting the wing permanently (presumably with dowels in the front and screws in the rear) and recovering. The saddle TE will just need a piece of balsa/ply to cover the gap and a patch of covering.

My 2c, David.

Hey David, I thought you would be building.

The wing actually fits good, it's just set in the saddle without snugging it up. It's the gap in the back that puzzles me.

I'll fill it with solid balsa, strip the center part of the wing the with of the fuselage and about 3" long, mount either bass or plywood where the wing bolts go, glue a balsa block to the bottom of the wing, feather it into the wing bolt locations and the block in the back, drill and tap (or inserts, I have both) cover and be done with it.

I was just wondering if the plans showed that you would end up with a gap if you didn't put another piece in.

Anyway, as long as I know it is typical to have a gap that needs to be filled I can continue.

Photos to come.

In that case... I withdraw my comment.

One other possibility is that the plane was built with the idea of using electric power. Leaving an opening behind the wing TE is something I've seen on a few designs/builds. Personally, I prefer the idea of putting the air exhaust in the fuse bottom behind the wing not at it's TE.

David.

I just found out the wing mounting dowels are wonky. One of the is higher so I filled in that mounting hole and I'll adjust it.

I pulled of the covering from the block on the LE and found it was mounted wonky too so I'll have to sand it to fit the fuselage. I like the way this box is made so I'll do the same in the back.

Rangerman

If you working with a SK-40, the gap looks to be okay per the plans and
construction photos (see attachments). SK-60 may have gap also but not
as much as the SK-40. No photo of SK-60 wing to really tell how much.

Yep there it is Rangerman. Ron pulled it out for you!
You seem to be missing a block at the TE to fair the wing to the fuse.


Is this the 40 or 60?


DM

IF you have a slight gap in the wing sadde/wing join, but the wing and fuselage are both properly-aligned, don't sweat it. It's not a big deal. Just wrap a piece of plastic wrap or dropcloth around the wing where it will join the wing saddle. Then, apply a bead of clear silicone bathtub caulk around the wing saddle. Mount the wing and allow it all to cure. When the silicone is cured, remove the wing. The plasic wrap will easily peel from the silicone. Now you just use a very sharp single-edge razor blade to trim the silicone flush with the fuselage/wing fillet. You'll have a perfectly-fitting, nearly invisible joint.

If you fly with the gap, don't be at all concerned about "air pressure" getting inside the fuselage and causing problems with the wing bolts. That's just a non-starter. You won't get such a thing happening at all...whoever told you that didn't really know much about how things work. The only thing you need to worry about making sure the holes in the wing are properly-aligned with the holes in the hold-down plate. For best fit, you want zero gap between the wing and the hold-down plate. A gap there will allow the bolts to flex side-to-side, and could cause them to fatigue and weaken. When you have zero gap, the bolts will shear neatly if the wing is struck and tries to pivot...unless the bolts are much too big.

Thanks Ron.

It's big so I would say the 60.

Tim

The Super Kaos is on the SPA website as legal. Do you have any mods to make it illegal?

Is there any such mod besides retracts and pipes? Look at some of the allowed "legal versions" of some of the others like the stretched so called Dirty Birdy with 4 stroke 90.

Terry in LP

Bill,

I think the point you're making is the same one I was trying to make - perhaps not explained well on my part (at least the second sentence in the second paragraph). As you state, a poorly mated wing will cause the mounts and bolts to fatigue (~my third sentence). I said "air pressure" while you say "a gap there will allow the bolts to flex side-to-side". The underlying idea is the same. If a gap exists at the mount points, in a snap (for example), air pressure would be responsible, at least in part, in causing the joint to flex unduly.

Perhaps you interpreted my comment as air pressure affecting the bolts directly, which is clearly not the case. As someone with two degrees in physics - I have some basic understanding of mechanics and fluid dynamics. In any event, I'm sure Tim will do a great job on improving the situation on his SK.

David.

HMMMM...I'll have to check that out. One of the guys that helps with the event said he didn't think it was.

Thanks, Tim