tripod mount and screw like?

Discussion in 'Camera Building, Repairs & Modification' started by Schunn99, Nov 12, 2008.

  1. Schunn99

    Schunn99 Member

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    hey all,

    I was wondering if anyone knew the size of a tripod mount?

    Also I am looking for a rod that has threads drilled into the shaft. The rod is inserted into a hole drilled into wood of the same size as the rod. It is like the other part of the tripod that screws into the threaded tripod mount. Does anyone know what that is called? I want to find if it is on mcmaster's.

    thanks,
    Scott Hunnicutt
     
  2. asp.artist

    asp.artist Member

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    A tripod mount is 1/4 inch. I'm not clear on the rest.
    Anne
     
  3. Jim Fitzgerald

    Jim Fitzgerald Member

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    Scott, I think what you are after is a "T" nut. If you are looking to have the piece that goes into the camera bed and the tripod screws into it this is what it is called. Be sure to get the one that you can use small screws to attach it to the bed. Do not get the one with the barbs that you have to pound in. Depending on the camera size and your tripod head you have a choice of 1/4-20 or 3/8-16. I used the 1/4-20 on my 8x10 and 8x20 and on my 11x14 I used the 3/8-16 to help support the heavier camera. I use mine without the quick release plates.

    Jim
     
    Last edited by a moderator: Nov 12, 2008
  4. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Hi Scott. The standard screw mount is 1/4"-20 to be exact.

    The fitting you are looking for is called a T-nut, but in brass it is also simply called a "threaded insert" like here:

    http://www.woodcraft.com/family.aspx?FamilyID=1048&cs=1695&pcs=fam

    EDIT- Jim and I posted at the same time. He is right in that larger cameras, particularly motion picture cameras use the heavier 3/8 size. Most standard tripods for photo are 1/4"-20 though. I would like to know a source for the nut with the 3 screw holes.
     
  5. Curt

    Curt Subscriber

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    Are you talking about the center post which might have a hole drilled in the top for mounting a tripod head? Is it an old or new unit that you are asking about?
     
  6. Lee L

    Lee L Member

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  7. Schunn99

    Schunn99 Member

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    thanks, everyone. The threaded insert is what I was looking for. but where do I find the threaded insert with the screw in it. mcmaster has the pound/drill hole and push in kind.
     
  8. Jim Fitzgerald

    Jim Fitzgerald Member

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    Scott, the T nut or insert is separate. The screw you will have to find on e-bay or from I think it is Bencher.com. If you google Majestic tripod heads there will be a site for parts for tripod heads. They sell the screw with the large nob on the end.

    Jim
     
  9. Steve Smith

    Steve Smith Member

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    1/4" 20 threads per inch. Also known as 1/4" Whitworth (well... it is over here!).


    Steve
     
  10. ricksplace

    ricksplace Member

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    Careful.... British Whitworth thread has a 55 degree "V", Most other threads have a 60 degree "V".

    Many years ago I had a 650 BSA. All British Whitworth thread. So everytime something vibrated loose (and God did that thing vibrate) I couldn't just use any nut. I had to order a whitworth thread nut.

    British Lee Enfield receivers have a 1"X14tpi receiver thread, but barrel threads must be cut with a 55 degree thread to mate properly with the receiver threads.

    Sometimes the clearances are sloppy enough parts will fit even though the threads are dissimilar.

    In North America, threads are usually designated as UNF or UNC now. (Unified National Fine, and Coarse) and have a 60 degree "V" with a small radius at the point.

    Rick.
     
  11. richard littlewood

    richard littlewood Member

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    1/4 inch Whitworth, and the bigger size is 3/8 inch Whitworth. I really like the idea that even the most advanced digital stuff still uses these obsolete (apart from cameras) threads.
     
  12. bdial

    bdial Subscriber

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    You can likely get the inserts, screws, knobs, etc. from your local "real" hardware store.
    Even the big box home centers have the stuff, but hardware stores are more fun, plus you can buy just one instead of a package of 5.
     
  13. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    It isn't 1/4" Whitworth... It is 1/4-20 UNC - a US screw thread.

    As for Whitworth http://www.jag-lovers.org/xk-lovers/library/whitworth_system.html

    One of the reasons that, as is often said of trying to keep a Jag running in the US, "All the parts that fall off are of the finest British manufacture."

    And there are lots of WWII stories about trying to fix Sherman tanks and Jeeps with Whitworth fasteners.
     
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  15. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Barry Young, who is an APUG member, made a couple of them for me. His prices were very reasonable, and he can machine them to order. I used them to add second tripod sockets to my 11x14" American Optical and 7x17" Korona, so that I could use them with Arca-Swiss style plates without worrying about the camera twisting on the plate and for extra rigidity. Now I can turn the Korona sideways for verticals.
     
  16. Greg_E

    Greg_E Member

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    Big/heavy cameras should use the 3/8-16 screws. I have not seen those "sockets" that can be screwed to the outside of a camera for sale anywhere so I would follow the advice and contact Barry.
     
  17. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Mine are mounted with the flange recessed inside the camera bed, top of the flange flush with the inside surface of the bed, so the tripod screw pulls the socket tighter and there's no danger of the socket getting ripped out of the camera bed. Barry can also make the flange diameter, barrel diameter, overall length, and screw thread to order, which is a considerable convenience. I had mine made so that I wouldn't have to buy any new drill bits, and so the overall length would correspond exactly to the thickness of each camera bed.
     
  18. Steve Smith

    Steve Smith Member

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    It's 1/4" and 20 tpi no matter what you call it. The only difference is the core diameter. 0.186" for UNC and 0.1887" for Whitworth.

    The British Standard Whitworth thread was specified in 1841. During WWII there were compatibility problems with various British, US and Canadian thread standards which lead to the UNC and UNF threads being adopted in the US in 1949.

    There were cameras in existence before 1949 with 1/4" 20 tpi tripod threads so I suspect that they were Whitworth.


    Steve.
     
  19. Frank Szabo

    Frank Szabo Member

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    Typically, the thread on the top of the tripod column is a .375 - 16 tpi (3/8) and the wrinkles in a camera's bottom can be either the 3/8 - 16 or 1/4 - 20. Bushings are available at camera shops to screw in to the camera's mount to adapt the 3/8 thread to 1/4.

    Were you speaking of the camera mount on a head or the tripod's connection?
     
  20. John Koehrer

    John Koehrer Subscriber

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    I've gotten both sizes with the 3 screw fastening from Rockler.com
     
  21. Lee L

    Lee L Member

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  22. ricksplace

    ricksplace Member

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    Actually, UNC is Unified National Coarse, pretty much the same as the old USA standard which was SAE (Society of Automotive Engineers). The difference is in the small radius at the bottom of the V. I can't remember what the change was for sure. I think the USA thread had a sharp V at the bottom of the thread, and the Unified National Thread (adopted by US, Canada, and I'm not sure who else) has a small radius. The old SAE threads will fit just fine with the newer Unified thread.
     
  23. Steve Smith

    Steve Smith Member

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    The world's most common thread? This must be the 1/4" x 20 t.p.i. Whitworth form found in the base of a camera that allows it to be fitted to a tripod or other mount. It's common to every camera maker and every model they produce - though some heavier professional types have, as a concession, fitted with a more robust 3/8" x 16 t.p.i.


    From this page: http://www.lathes.co.uk/latheparts/page6.html



    Steve.
     
  24. twalsh341

    twalsh341 Member

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    It's not about what you call it. It's designation of a codified standard. You can have a 1/4"-20 tpi box thread and that isn't going to fit a 1/4"-20 Nation Coarse which is sharp V (60 degree). Threadform is just as important as size and pitch. Even if the wrong pitch "fits" because it is sloppy enough means it will wear quicker and all need replacing.

    The minor diameter difference is because Whitworth has a steeper thread, thus the root diameter is larger because the depth of the thread is shallower off of the major diameter of the screw.
     
  25. Steve Smith

    Steve Smith Member

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    A four year old thread revived!

    Yes, One has a 55 degree cut angle and the other is 60 degrees. I forget which way round it is. As you say, if you put the screw of one into the thread of another there will not be a flat to flat surface bearing the force. It will work but will wear with continued use.

    The original difference of opinion here was with which thread was used. I claimed Whitworth but others (usually Americans) thought it was UNC. The fact that many cameras were made with 1/4" x 20 tpi threads before UNC was unified makes me think that it was originally Whitworth.


    Steve.
     
  26. Jim Jones

    Jim Jones Subscriber

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    The 1952 ASA standard tripod screw specification is 1/4 - 20 TPI UNC-1A thread (and 3/8 - 16 UNC-1A for larger cameras) on American cameras. Perhaps in England the Whitworth form was used. Several variations of T-nuts and threaded inserts in these sizes are readily available over the counter in Ace Hardware Stores in America. David Goldfarb gives good advice above on mounting a T-nut so the tripod pulls it against the wood of the camera rather than relying on little screws to hold the T-nut as seen in some imported pinhole cameras.