Repairing tripod socket on Speed Graphic (5x7)

[domaz]

Well the good news is a found a 5x7 Speed Graphic recently for a good price. The bad news is I found out the tripod socket is stripped out somehow. The side tripod socket seems to work fine takes a standard 1/4" screw. But the main tripod socket on the bottom seems like it is too big to take a tripod screw but it's definetly not a 3/8" socket. Can anyone give me a general idea of how to remove the old tripod socket and replace it? Or is this a harder job than I realize?

[E. von Hoegh]

Maybe it's a 5/16" thread?

[domaz]

Maybe it's a 5/16" thread?

I'll give that size a try. But it would be strange to have the side socket be one size and the main socket be another. I suppose the previous owner (engraved University of Michigan Botanical Gardens interestingly) might have swapped the tripod socket for some reason.

[cyrus]

Is it stripped or just another size? I guess it depends on how badly it is stripped. Other than drilling it out and then gluing in an adaptor that takes a standard 1/4" bolt I can't think of any other option. I did this once using 3M's Marine 5200 glue. It works but ain't pretty (leatherette covered up the mess)

[Jim Jones]

I don't recall just how the tripod socket is mounted in that camera, but a 1/4" T-nut available at almost any hardware store seems like the easiest fix. T-nuts come in different styles. Hardware stores also have threaded inserts to screw into wood and tapped for common bolt sizes, but the bottom plate of a SG may be too thin to properly support such a shortened insert. When using these inserts, I prefer to epoxy as well as thread them into place for maximum strength.

[Greg Blank]

I would have it remachined. I would check with SK Grimes to see if they can do it.
Ultimately the idea would be to insert a plug that won't move, perhaps even screwed into the camera base. Then the plug is reamed back out to the required size using a tap on a drill press. To do a "good" job having a specialized chock for the tap is required.

[Steve Smith]

I would have it remachined. I would check with SK Grimes to see if they can do it.

So would I.... To the correct Whitworth thread size, not UNC which is slightly different as far as the cutting angle is concerned.


Steve.

[E. von Hoegh]

So would I.... To the correct Whitworth thread size, not UNC which is slightly different as far as the cutting angle is concerned.


Steve.

Woah!!!!
This is 1/4-20 UNC, on a Speed Graphic. Tripods have 1/4-20 UNC screws. Why Whitworth? It's not an old Beezer.

[Steve Smith]

Woah!!!!
This is 1/4-20 UNC, on a Speed Graphic. Tripods have 1/4-20 UNC screws. Why Whitworth? It's not an old Beezer.

Because cameras have always had 1/4" (and 3/8") Whitworth threads, not 1/4 - 20 UNC.

Screw thread
The historic standard threading for the bolt that attaches the camera to the tripod is 1/4"-20tpi (threads per inch) British Standard Whitworth (Whitworth or BSW) for smaller cameras or 3/8"-16tpi BSW for larger cameras and pan/tilt heads. Bolts using 1/4"-20 UNC and 3/8"-16 UNC screw threads are generally close enough to work when BSW bolts are unavailable. Note: A BSW bolt in a UNC nut has play, but a UNC bolt in a BSW nut will jam.

From: http://en.wikipedia.org/wiki/Tripod_...)#Screw_thread


Steve.

[Jim Jones]

As of 1952 the American Standards Association's specification for tripod sockets was 1/4-20 UNC-1B and 3/8-16 UNC-1B. I don't have later specs or information for other countries.