Rib Shift

Fabric and covering. Fabric, dopes, paint and everything associated with the coverings on our planes.
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MikeB
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Rib Shift

Post by MikeB » Tue Jun 29, 2010 14:45

OK! What did I do wrong? (I probably know the answer but thought I'd share my frustration).

I pretty much had the inter rib bracing tight, although after turning it over several times during the covering process they may have loosened some. I have a couple of ribs that shifted during the tightening process....one being the second inboard that hold the fuel tank which was straight when I started and the other being the out board aileron bay rib which pulled futher outward dispite the fact that I installed the recommended brace from the spar to the tip and fabricated a plywood reinforcement for the rib. This caused the rib to bow somewhat.

I thought I had things pretty well 'stiffened up' but apparently not. I realize it's all cosmetic but I'd like to correct the situation on my next wing if possible. All the other ribs are straight as far as I can tell. I've seen a fabricated brace from the bow to the center of the outer aileron bay rib but didn't think it was necessary.............. :?

MikeB
Last edited by MikeB on Tue Jun 29, 2010 18:10, edited 1 time in total.

jepropst
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Re: Rib Shift

Post by jepropst » Tue Jun 29, 2010 17:40

During my (first) wing recovery, I anchored the rib bracing to the wing bow on the outboard end. I found that as I shrank the fabric, it drew the wing bow in a little bit which loostened the anchor point and thus loostened all the rib bracing allowing some of the ribs to move. I started straightening each rib by drawing a straight line where the rib should be located. I took a Craftsman screwdriver that has a smooth round knob on the end of the plastic handle and, by gradually working each rib over through the fabric, was able to move them into position. As I got each rib in position, I inserted a PK screw and washer to hold it in place. Some ribs required several screws to keep them straight. Afterwards as I started placing the reinforcement tap over each rib, I would have to advance one screw at a time so that no more than one screw at a time was removed and replaced. I thought I learned my lesson on the first rib and installed 5 rows of rib bracing on the second wing. This really didn't help much more than the three rows I had on the first wing.
John Propst
313 Hickory Grove Ln
Elizabeth, WV 26143
cell 304 588 3690
j.e.propst@ieee.org
N3129E 2WV3

MikeB
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Re: Rib Shift

Post by MikeB » Wed Jun 30, 2010 05:45

The fabric is pretty darn tight but I'm wondering if I wet the fabric a bit on the affected ribs that I might be able to shift the ribs to a straighter position by working them with my fingers.
Guess I need to walk away from it for a day or so............ :evil: :evil: . This being my first wing, I'm still in the 'learning' stage.

Mike

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Nathan K. Hammond
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Re: Rib Shift

Post by Nathan K. Hammond » Wed Jun 30, 2010 08:44

Know the feeling Mike. We ended up using several pieces of welding rod taped together with a small hook bent on the end. Then fish it through any opening in the wing to move th ribs around.

But John's idea of using a plastic screw-driver handle is pretty slick. I doubt you'd need to use any kind of water; polyester is slick enough.

nkh
7AC-5691
Super 85-12F @ DVK

MikeB
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Re: Rib Shift

Post by MikeB » Wed Jun 30, 2010 14:13

Image
The answer: it must of helped to go flying this morning :D . After thinking about John's post, I tried moving the ribs around and cleoing them in place (I have the new .032 ribs with 1/8 holes for pop rivets). It worked....at least on the bottom part......thanks, John!! Using pop rivets in place of PK screws goes pretty fast, although there are a couple of steps that need to be taken. I'll post some pictures on the "restoration thread" later. You'll note I wasn't able get rid of the "Aeronca bend" at the outboard aileron bay but guess I'll just have to live with it on this wing and see if I can improve on the next one. The fabric is some wicked stuff once you start to tighten things up. Lots of creaking and groaning...... :| .

MikeB

CptKelly
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Re: Rib Shift

Post by CptKelly » Tue Jul 06, 2010 10:38

MikeB,
Check your PM inbox.

Mike

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