My Flexy Rack-nearly done.

Discussion in 'Archived Threads 2001-2004' started by Marc_E, Nov 14, 2001.

  1. Marc_E

    Marc_E Supporting Actor

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    Started painting the MDF on Saturday (flat black to match the TV). I couldn't find 72" 5/8 all threads so I bought 6 36". The plan was to fuse two racks into one monstrous one (I have 10 components including the new LD player!). So the rods would be the 2x1 design then half way the 2 would switch sides with the 1 for the 'second' half of the rack. Is working out quite well so far. I should have it completed by the weekend (wont have any time until then..SLAYER concert tonight in Boston)..I need to paint 2-3 more shelves and I need daylight for it so the only possible day is Saturday. As soon as it is done I will post pictures w/ and w/o equipment on it and, what the hell, the whole HT!
    Marc E
     
  2. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Can you explain the 2x1 and 1x2 pattern carefully for me? It sounds like you're doing 2 all-thread rods on the left and 1 on the right for the bottom half and then 2 rods on the right and 1 on the left for the top half. Or maybe the mirror image of that.
    So with this setup you would have a shelf somewhere in the middle of the rack that does the 2x1 to 1x2 switch, right? Do you realize that this puts the entire weight of the upper shelves on the one middle shelf that does the switch. Once you load this thing up with components, that "switching shelf" won't last long.
    I remember a story in an Engineering Ethics class at college about a multi-level walkway failed because of a similar problem. The builder couldn't find support poles long enough for the total height so they used multiple, shorter poles without consulting the designers. Their change (similar to the rack design I described above) put the weight of each walkway upon the walkway below it instead of transferring the weight directly to the ground. People died when it fell.
     
  3. Robin Smith

    Robin Smith Stunt Coordinator

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    I agree with Ryan, that middle shelf is going to flex and or break. A nasty thing with all your expensive equipment on it. The point of the rod is as Ryan says, it transfers the weight down a single vertical mass all the way to the floor.
    Similarly, most houses have at least one internal wall that continue form the top of the house to the basement floor (even if in the basement it is a pole. This design stops the house from settling/bowing due to the weight transfer from the floors above.
    If it were me, I would change your design to be two racks 36" high instead of one 72" rack, or try to find 72" rod.
    Sorry that you have to rethink your plans, but I think you'll regret it in an expensive way if you continue with your current plan.
    Robin Smith
     
  4. Marc_E

    Marc_E Supporting Actor

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    I very much appreciate the input/concerns.
    The first half was to contain my heaviest units (receiver-47lb, DVD-47lb, Laser-30lb,tivo-20lb,2nd reciever-25lb. and the 2nd half was to have the light units VCR, tape deck, minidisk, sat box each about 5-7lb.
    The rack is 90% complete [​IMG].
    Do you guys think it will survive with all the heavies on the bottom half and very lights on the top?
    Thanks again...oh, I am not engineer as you can see. I am just a chemist/Dad.
    Marc
     
  5. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    It might be okay for the lightweight stuff. Depends on the construction. There are some guys here that really know a lot about the strength and stiffness of different woods, but I'm not one of them.
    Try adding up the weights of everything above the "switching shelf". Include the all-thread rods, shelves, components on the shelves and the component sitting on the "switching shelf". Then figure out how much your switching shelf can support based on its wood type, thickness and the longest distance between the rods that support it (sorry I can't really help much with this part). If there's plenty of margin between what it can support and the weight you're planning to put on it, then you're okay. But if not, then consider some method of strengthening the switching shelf.
    A simple solution might be to just glue two shelves together to form a double thick switching shelf. But you may come up with something more exotic.
     
  6. Marc_E

    Marc_E Supporting Actor

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    Hm....
    I like the two shelf thing!
    Glue here I come.
    Thanks a lot guys.
    Marc
     
  7. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    You still may want to check that 2X thickness is enough. But now that you're aware of the potential weakness and taking measures, I think its much less likely that we'll hear a tragic story of 10 components dying in a freak audio rack collapse accident.
    I'm looking forward to your pictures.
     
  8. Dan W.

    Dan W. Auditioning

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    Rather than having the rods switch sides and relying upon the strength of the shelf for supporting the top half, you could also use threaded couplers to join two 36" rods together into a single 72" rod.
    This is what I've done in the past for a tall DVD/CD shelf unit I built. I think this would give you the strongest solution overall. The couplers should be available from the same place you purchased the threaded rod.
    Regards,
    Dan W.
     
  9. Marc_E

    Marc_E Supporting Actor

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    That sounds very promising too.
    A trip to homedepot today after work.
    Thanks guys!
    Marc
     
  10. Marc_E

    Marc_E Supporting Actor

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  11. Philip Hamm

    Philip Hamm Lead Actor

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    Holy gee wilikers! I've never seen such a tall flexy! Hope it's stable!
     
  12. Marc_E

    Marc_E Supporting Actor

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    It is quite stable actually, the real monster units are on the bottom (50lb receiver) and the light stuff is up top.

    Marc
     
  13. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Looks very nice. I'm tempted to try a short, double-wide flexy to hold my components and TV.
     
  14. Jon_B

    Jon_B Screenwriter

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    Wow, that thing is taller than half the buildings in montana. [​IMG] Looks good though. [​IMG]
    Jon
     
  15. Jin E

    Jin E Second Unit

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    Well... while we're sharing Flexy pictures...
    [​IMG]
    I didn't spend much time on it. I basically thre it together but it works pretty good. I didn't use MDF... I used a glued pine board (probably a mistake... but I had some laying around). Works pretty good... looks better in person. Next time I will take more then 20 minutes sanding and finishing my rack.
    BTW... the "blemishes" on the bottom shelf are actually reflections of the knobs of the Integrated Amp. It has a really nice high luster to it.
     

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