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Thread: drag/antidrag wire conflict with ribs

  1. #1

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    drag/antidrag wire conflict with ribs

    Putting together a Hatz CB-1 and am encountering some conflict with the internal brace wires and the ribs. I can displace the ribs a bit sure prefer equal spacing. I'll notice it the rest of my life even though it would probably be less than 1/2". Should I notch the rib elements and then reinforce them with some short beveled pieces of capstrip or move the ribs?

    Sarpy Sam

  2. #2

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    Moving the ribs slightly is a much better solution than weakening them. You can move the adjacent ribs slightly so that you do not have one rib that looks grossly out of place.

    Best of luck,

    Wes
    N78PS

  3. #3

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    I can displace the ribs a bit sure prefer equal spacing. I'll notice it the rest of my life even though it would probably be less than 1/2".


    You write that like it's a bad thing!

    They say that perfect is the enemy of good, but that depends on what considers perfect. "Perfect" is unaltered ribs with a little offset, IMHO. And you can look at the minute change in spacing and smile, knowing that you used your brains to come up with a simple and effective solution to a design problem.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  4. #4
    planecrazzzy's Avatar
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    Quote Originally Posted by Frank Giger View Post
    You write that like it's a bad thing!

    They say that perfect is the enemy of good, but that depends on what considers perfect. "Perfect" is unaltered ribs with a little offset, IMHO. And you can look at the minute change in spacing and smile, knowing that you used your brains to come up with a simple and effective solution to a design problem.[/COLOR]

    Well said... I'll second that...
    .
    Gotta Fly...
    JAM

  5. #5
    cluttonfred's Avatar
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    I'll notice it the rest of my life even though it would probably be less than 1/2".
    I hear you on that but I think that slight changes in rib spacing should solve your problem. In fact, knowing that there is usually less lift being produced the further you go out in span and assuming the the other ribs are not yet in place, you might even mess around with the spacing to have it increase steadily as you move towards the tip.

    Have you checked with other Hatz builders on how they have tackled this?
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  6. #6
    crusty old aviator's Avatar
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    If shifting the ribs on the spars for wire clearance just doesn't sit well with your sense of order, and you do decide to notch any diagonals or verticals in your ribs, make sure you sister another piece of cap strip on the back side of the notch, the full length of the notched piece, and sandwich the two between two, full width strips of 1/16" birch or mahogany plywood. Leave your tack hammer and nails in the drawer, hold it all together with mild spring clamps, like clothes pins, and wipe up the squeeze-out that runs and drips. But first, follow Mathew's sage advice and check with the Hatz builders' group for their established fixes.

  7. #7

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    I have notched built up ribs on two different homebuilts and I'm still alive to tell about it. It's done often and as long as you account for the lost material and glue a scab along side the notch only you will know. I would rather notch a diagonal over moving a rib. Thats two cents of information for free. good luck.

  8. #8
    Neil's Avatar
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    I wouldn't mess with the rib spacing. I had an issue the same as you on my Acro Sport II as an anti-drag wire centered a vertical. I just added a splint on each side and even let them run into the gussets for good measure.
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  9. #9

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    Thanks for the input guys. I ended up notching, laying in another piece of capstrip and scabbing on a piece of plywood on both sides. The ribs are evenly spaced! I'm happy!

    Sarpy Sam

  10. #10
    Jim Hann's Avatar
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    Just for reference here is how my PA-22/20 wings handle it, they just bent the diagonal to clear. I wouldn't be worried with what you did!
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    Jim Hann
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