Correcting rib shape late in the build

Discussion in 'Construction' started by darkapollo, Apr 25, 2021.

  1. darkapollo

    darkapollo Well-Known Member

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    My wood hull Bis was based on the plans from another members build which turned out very nice. However when I went to sheet it, I realized that there were numerous ribs that are not correctly shaped above the armor belt/stringer. I attempted to correct them but the shape was too far off making the ribs very thin in that area (which is why they broke there). I was going to just deal with it. After the Bis took a nasty fall and broke a few ribs, the keel, and subdeck, I have been weighing cutting the bad ribs and correcting them during the 'repair dry dock' (she has been repaired and on the water but there is water seepage from somewhere in the stern that needs addressed). Now that my CNC router will be back from the dead after 8 years I have the ability to cut new sections accurately and quickly.
    I have a few options for this repair but would like the opinions of vets. I could cut the ribs just at the top of the stringer and replace them with just the armor belt corrected sections.. I could cut them at the waterline which would correct the shape of the rib, or I could cut them at the 1" below waterline mark and replace nearly the entire rib.

    My question is:
    Is it worth trying to save the ship or just start a fresh build with correct rib shapes?
    If it is, how would you splice the old rib with the new rib?
    -- I was thinking of a few ways to do this. I could create a jig to cut a pattern (like a VVV or keyway) into the remaining rib section to maximize the surface area for the epoxy to grab, or try to splice the ply layers together like a finger joint (way beyond my tooling ability but I know people who do wood working and might have a way to do that), making the stringer the full thickness of the rib to support the jointed area, or adding a splint.
    These are the 6 ribs that need to be replaced with a corrected shape. The line from the stringer up should be vertical not flared outwards. The 4th rib back is also terribly incorrect but Im not sure how to correct the entire rib at this point.
    upload_2021-4-25_12-40-36.png
     
  2. wfirebaugh

    wfirebaugh Well-Known Member

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    This why I like to 3D model things before I build things but at times there are still unforseen things that still pop up.
     
    Last edited: Apr 26, 2021
  3. darkapollo

    darkapollo Well-Known Member

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    I think I’m just going to start fresh with my own plans. The current hull would be fine for a strict battler, but as it may never see that in my care, I want to make the hull as correct as I can.
     
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  4. Xanthar

    Xanthar Well-Known Member

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    You could always "sister" the ribs that need attention. I think that you may have gotten the further with that set of ribs than anyone else did. So in your expert opinion, what could we, collectively, to do improve upon on Daniel's files and make a freely available and usable Bismarck?
    I've been messing around with several different meshes for Bismarck and Tirpitz and they all have some issues.
    I really like the hull I bought from @modelshipsahoy but, it was made to an exaggerated length for Tirpitz that, from what I've read, is inaccurate. That's not a knock on Tim or Ralph it's just that some bad information was generally assumed to be correct for a long time and it has only recently been refuted.
    That said, if we could get Daniel's ribs to better agree with the beautifully shaped MSA Tirpitz then one could have common superstructure and deck parts. Maybe even some common drive line components?
    What do you guys think?

    PS. I think that I saw a thread where Tim had installed a Battler's Connection Deck kit into one of his hulls so, the deck profile isn't too different from the BC hull. I think it'd be nice for a new builder to have parts that work for all three.
     
    Last edited: Apr 26, 2021
  5. darkapollo

    darkapollo Well-Known Member

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    Honestly, IF one was so inclined to fix them, it would be just a matter of fixing those 7 ribs starting at the last cross piece and going back to the last stringer. There is one (seen on my build and his) that is too shallow. I want to say Rib 21, but not 100% on that. The ribs overall are pretty good. If you were building a battler and didnt care about showing the armor belt (easier to sheet that way) they work perfectly fine. It was when I started sheeting it that I noticed how wavy it was. I debated not showing the armor belt but I personally love the look.
    I’m working on my own rib set that can be printed, 3D printed, or CNC routed.
     
    Devasen likes this.