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Wing Inter-Rib Bracing...What to do???

Buzzcola777

Buzzcola777

MEMBER
Montreal, Canada
Gents,

Still in the process of ordering items for the covering. Looking at the drawing #12451, Piper shows the method of inter-rib bracing.
I've looked at a bunch of pictures on the Web and some wing have them some don't...

[FONT=&quot]AC43.13-1B / Poly Fiber and other reading materials instruct you how to zig zag this between the ribs and how to knot them at each crossover point. The bracing is designed to keep the ribs from deforming during the fabric shrinking process.

[/FONT]Was this inter-rib bracing done only for the old piper wings? Do I need it or not? What do you guys do?
 
I am with Mike. On a Cub, after shrinking, you can reach in with a needle and move a rib straight.

However, on the Taylorcraft I am working on, a needle pressure would break a rib, so I used the newer synthetic stuff. Still didn’t get it perfect. I can get a Cub wing dead straight without them. In fact, I bet I couldn’t move a rib under the cover if the tapes were in there.
 
Yea, you can move it but can you keep it straight while you stitch it. Why wouldn't you use the inner rib bracing tape?
 
If I were buying a plane and didn't see it i'd wonder what else didn't the builder do
 
Once the ribs are dead straight and the fabric shrunk, that first coat of dope will capture the ribs, making stitching mindless. You can still snap it loose if you see a crooked rib.

MT - don't buy mine when I croak. Dead straight ribs but no bracing. Buy the new Cub - it came covered with bracing. I have threatened to recover the wings just to get those ugly curves out of the ribs, but instead I just fly the socks off it.
 
Steve Pierce said:
Yea, you can move it but can you keep it straight while you stitch it. Why wouldn't you use the inner rib bracing tape?
Click to expand...

Steve,
Not that I don't want to use it, I was just wandering why some people use it and some don't... On the Smith Wing the cover is extended about 24'' from the LE...Is it still required?
Dan
IMG_1469.jpg
 

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Your ribs look the same as mine from Backcountry. If so? They're way more rigid than old Piper ribs. You shouldn't need to stabilize them, especially with extended LE metal.
 
Dan, A tip when covering your wings. Put the covering on the bottom first, shrink it enough so that it won't move when the final shrinking is done, then stitch the ribs forward of the aft edge of the extended top leading edge. Then cover the top, shrink and do the full rib stich. It's easier to get your hands in there to stich the bottom under the leading edge.

I agree with Steve, the trailing edge of the extended leading edge is attached where the X bracing is placed. The whole idea of the X bracing is to hold the high portion of the rib from sliding sideways when the pressure of the shrinking fabric wants to pop the ribs sideways. With that extended leading edge there are no unsupported high spots on the ribs.
 
skywagon8a said:
, then stitch the ribs forward of the aft edge of the extended top leading edge.
Click to expand...

There’s no use stitching just the bottom of ribs.

Some planes have no bottom of rib,or any fabric attachment

There’s really zero reason to stitch bottom at all...

you usually skip it when replacing a bent rear spar in a covered Piper wing.

Unless you plan on flying inverted.....



Sent from my iPhone using SuperCub.Org mobile app
 
mike mcs repair said:
There’s no use stitching just the bottom of ribs.

Some planes have no bottom of rib,or any fabric attachment

There’s really zero reason to stitch bottom at all...

you usually skip it when replacing a bent rear spar in a covered Piper wing.

Unless you plan on flying inverted.....
Click to expand...
Then why is the fabric sewn to the ribs under the gas tank? It is to stabilize the fabric to prevent wear from abrasion and flexing. It also helps to stabilize the ribs, reducing their ability to flex and crack. Stitching the bottom of the ribs is easy, takes very little time and just makes the fabric and ribs a bit more secure.
 
I also saw someone drill holes in the extended leading edge so they could easily stitch the ribs under them. There is also a way to cross stitch them as well.
 
My
Ext leading edges are drilled for lacing.
 

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skywagon8a said:
Dan, A tip when covering your wings. Put the covering on the bottom first, shrink it enough so that it won't move when the final shrinking is done, then stitch the ribs forward of the aft edge of the extended top leading edge. Then cover the top, shrink and do the full rib stich. It's easier to get your hands in there to stich the bottom under the leading edge.

I agree with Steve, the trailing edge of the extended leading edge is attached where the X bracing is placed. The whole idea of the X bracing is to hold the high portion of the rib from sliding sideways when the pressure of the shrinking fabric wants to pop the ribs sideways. With that extended leading edge there are no unsupported high spots on the ribs.
Click to expand...

Thanks Sky! Very good tip!!
 
I am doing the Poly Fiber "Island/palm tree/rabbit" stitch now. It works under the tank, using the curved needle, if you can't get to the inside for some reason.

I have seen experimental airplanes with no rib stitching. I assume it works, but we need to put the stitches in or get a field approval. I personally cheat on the vertical fin; no more stitches there. Well, I will put them in, but they break right away.
 
I’m with Steve on this technique.
Though I have found it best to fabricate your own needle for this operation.
piece of welding rod (or coat hanger) pound one end flat and drill a hole for thread.
Most commercially avail needles are really stiff and won’t bend.
Its often necessary (or helpful) to be able to tweak and tailor the needle to your particular situation, stitch space, obstruction etc..
 
Yep, blind stitch the bottom and run them together just like a normal stitch, then when you get past the leading edge, start a normal stitch. Works great and pretty quick.
John
 
Buzzcola777 said:
Steve,
Not that I don't want to use it, I was just wandering why some people use it and some don't... On the Smith Wing the cover is extended about 24'' from the LE...Is it still required?
Dan
View attachment 53479
Click to expand...

So you're not drilled for lacing through the extended metal? Are you planning to? If not, are you comfortable with all that lift area being secured by a thimble full of #4 PK screws and glue?

What are other guys doing with extended LE metal? The reason I prefer metal is for how lift works the fabric in that area as the plane takes off and lands. I'm pleased that the area is laced on my wings.
 
Last edited:
Mine is drilled and laced. Just make sure that the holes are large enough and positioned over the cap strip by about 1/3 to eliminate a sharp edge that could cut into the lacing.
 
It looks like Buzzcola's metal is one piece outboard of the tanks? I've never seen that. No 90° flange over the upper spar cap. Maybe I just can't see it?
 
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