Installing the tripod bushing

Discussion in 'Camera Building, Repairs & Modification' started by schrochem, Sep 15, 2008.

  1. schrochem

    schrochem Member

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    I 'finally' have my Ries A250 on the way.
    It only took 3 months of waiting to get it, but it will be worth it.
    My Korona had a plate screw onto the base that had a quickplate attached to that.
    I removed the plate and the original bushing is pretty much gone and the hole is all torn up.
    I saw some nice 3/8" bushing at Lowe's that should work. They are the type that screw in. It's 7/8" long which is the width of the bed. The girth should be wider than the current hole so it will have enough bite.
    My question is how does the bushing stay put?
    The hole in the base goes all the way through.
    I was thinking of dabbing the exterior threads of the bushing in Liquid Nails before screwing it in.
    Any suggestions? I might only have one shot at it and don't want to screw it up. I am rebuilding a new base for the beast, but it's going slow......
    Thanks
    Scott
     
  2. jmcd

    jmcd Member

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    Personally, I would look for a tripod bush that mounts through the top of the bottom plate, with a large diameter nail-head type top, and a smaller threaded cylinder, the type used on Wisner and Ansco cameras. This way you are relying on more than threads in wood. These usually have three holes around the diameter of the top for small screws to hold it in place.

    If you are installing the screw-in type insert snug but not too tight, the threads should hold tight enough on their own, but a dab of glue (polyurethane or epoxy would bond to metal and wood) would not hurt. It is important to get the pilot hole exactly plumb, and to screw in the threaded insert mounted on a threaded rod backed up by two locking nuts. Spinning this set-up by hand mounted in a drill press while threading it into your wood will help it go in true. It would be very instructive to practice on some scrap of similarly dense wood.
     
  3. Lee L

    Lee L Member

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    In the US, this is commonly referred to as a T-nut. There are two types. One has nail holes through the flange and the other has metal "prongs" turned down off the edges to keep the T-nut from spinning.

    http://www.woodpeck.com/media/main_tnut.jpg
    http://www.allproducts.com/metal/eyelet/14-round_base_t_nut-s.jpg

    The T-nut should be installed so that the flange is on the top surface of the camera bottom plate. You can find T-nuts with shorter or longer threaded sections.

    Lee
     
  4. schrochem

    schrochem Member

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    Thanks I really like that approach better.
    Do any local stores sell these things?
    I found they are popular for climbing walls. Rei sells some of the pronged ones.
    I think the screw in type would be better and maybe easier on the old wood.
    I'll stop in Lowes tomorrow and see what they have.
    Thanks
    again
     
  5. freygr

    freygr Member

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    McMaster-Carr has the tee nuts. I got 100 for about 13 plus shipping.
     
  6. Jim Fitzgerald

    Jim Fitzgerald Member

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    Scott, you can find them at Lowes. Look in the drawers in the nuts and bolts section. They should be there. Make sure you get your hole drilled just right. I know that when I was building my 11x14 I put two holes in the bottom for this. I wanted the extra support. You may even want to use a small rectangular piece of brass to put down first to expand the area of these T nuts. I used some thin brass that I drilled two holes into and lined them up with the holes in the camera bed and screwed and epoxied the T nuts in. I even drilled some extra small holes in the T nut for extra support. It looks good and it is rock solid. It you need some pictures let me know.

    Jim
     
  7. schrochem

    schrochem Member

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    Thanks for the added explanation.
    I bought the 3/8" t-adapter at lowes but it's only 7/16" long.
    Looking around online, McMaster, Grainger, etc. that seems to be standard and I can't find one that is longer (the base is 7/8" thick).
    So, I might go with that screw in one after all. Maybe I can find a screw with a flange and attach that to the top of the screw.....
     
  8. Lee L

    Lee L Member

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    You may not want to do this with your camera, but at least with new construction you'd probably just counter bore a wider hole to accommodate the flange of the T-nut.

    The threaded inserts you mentioned earlier would be another option.

    Lee
     
  9. Jim Fitzgerald

    Jim Fitzgerald Member

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    Scott, you can use a Forstner bit to drill a hole and recess it into the base. I would go with the T nut and screw it in. Maybe even some epoxy to be sure. It will be easier than trying to screw a threaded insert into hardwood. Trust me on this one. I learned from experience. You can recess the T nut with the Forstner bit so that the nut is lower than the base. The bit will leave the mark to drill the hole through the base. Screws and epoxy and you are done. Make sure to pre-drill the holes. Just make sure the 3/8" bolt goes into the T nut as far as it can.

    Jim
     
  10. schrochem

    schrochem Member

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    Thanks for the recess tip. Are y'all suggesting I still do that from the top?
    Or would the bottom be fine?
    Thanks again
     
  11. Jim Fitzgerald

    Jim Fitzgerald Member

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    Scott, I did mine from the top. If you recess it and screw and epoxy it in the weight of the camera will pull it down and hold it tight.


    Jim
     
  12. Jim Noel

    Jim Noel Member

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    Always from the top if possible!
     
  13. John Koehrer

    John Koehrer Subscriber

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    If you insert it from the bottom it's weaker than going through the top. With the additional diameter of the flange there's no way it will pull through.
     
  14. schrochem

    schrochem Member

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    I was able to do it from the top.
    I hope it holds.
    The hole that was there had a smaller tnut for 1/4" (that had the bottom threads all torn).
    I was able to easily remove that but making the larger hole didn't go so well.
    Because there was already a 1/2" hole there, the 1" fortsner bit was a bit tricky.
    I was able to get it down to the right depth, but cutting it smooth and flat was tricky.
    So I added extra glue...
    I'm not sure the the three screws will hold but hopefully with all the extra glue it will hold.
    The head came in yesterday, so I'll give it a try tomorrow.
    Thanks for all the help.
     
  15. freygr

    freygr Member

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    Tee Nuts need to be installed from the top or you may have the camera fall off the tripod!

    As far as the screw in inserts, I tried to use them in my camera project and they would split the wood, at least the ones I got and the other problem they would never go in true, the Tee nuts will go in true each and every time. If you don't have space you can counter bore the top with a foster bit before you drill the main hole . Note use a piece of scrap wood to set the depth of the counter bore, which should be the thickness of Tee Nut flange.
     
  16. Joe VanCleave

    Joe VanCleave Member

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    I prefer using the tee nuts that have the three bent metal prongs. I start with a small pilot hole drilled through the wood, then a Forstner bit to make the counter sink for the tee nut's flange on top; then a bit to drill out for the main shaft of the tee nut. Prior to mounting the tee nut I'll press the three prongs into the recessed flange area, and drill small pilot holes into these marks for the three prongs. If you don't, the wood may split when you try pounding the tee nut into its seated position. Finally, a bit of epoxy glue to cover the upper flange area. Depending on the application (like a tripod adapter plate for pinhole box cameras, for instance) I'll cover the top flange area with a piece of sheet cork to hide the scar. For mounting the tee nut to the bottom of a wooden box camera, a piece of opaque wood or sheet metal goes over the scar on the inside of the floor of the box, to make the area light tight.

    ~Joe
     
  17. freygr

    freygr Member

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    How true, If you are building your own use plywood and you will not have the wood splitting problem. If the camera is heavy you should use plywood were the stress could go accross the grain to keep the camera or tripod in one piece.