Graflex.org

[Les]

I put out an APB to Grimes and a repair network. So far no luck but it's early.


Les

[RichS]

Well, it looked threaded... I only found out after I got the 3 inch release extender they sell for such applications. I screwed it in and when I went to put the shutter back in the baord it poped out. After the investigation, I gave it a _good_ twist in and it stayed. But I'm sure a decent yank on the cable and it would loosen up or pop out again. Of course I could easily epoxy the cable into place but that would take the fun out of finding the tap

And no, I never thought of contacting Grimes. Good idea, and thanks Les

But don't worry. I'l have a hundred or so made and then wind up selling them off at alf what I paid for them We'll see next week if that company responds to my query?


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"Ya just can't have too many GVIIs"
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[Les]

I've gotten several replies back, and they fall into two catagories.

A) let me know what you find, I"ve been looking too

and

B) just replace the part its easier


Which doesn't explain how the new parts are made if nobody will admit to having a tap.

[RichS]

[t.r.sanford]

Apparently, the mixed bag of "special" threads still subsumed under a recognized U.S. standard includes 50-tpi x 3/32-in. Eyeballing the end of a cable release and a steel ruler suggests that this might work, if the object were simply to thread a cylindrical hole. Such a tap ought to be available from somebody.

But what I do not understand is how one can cut threads inside a tapered hole too small to accommodate a boring-bar. I think this, rather than finding a tap of the appropriate pitch and diameter, is the really interesting question.

Might not an 0.5mm. thread work, more or less, for the relatively few turns needed to secure the release tip into the socket?

[Dave]

I don't think anyone's said this obvious thing yet-- did I miss it? Flame away if I'm stating the obvious.

You probably want to avoid screwing and unscrewing a cable tip in a tight space on a recessed board. You need one of those angled adapters for a recessed board. You can get them in different shapes-- I used to have one with about a 60degree bend (1.05 radians). It had a pivot in it, so it would swing around freely. You can find one for like ten bucks on ebay, or get it retail from Calumet or whoever.

The advantage of this is you only have to fasten the adapter once, and it becomes your new shutter release socket. If you can jam it on even cross-threaded (or carefully glued?!), it buys you a decade or two before you have to think about it again.

[t.r.sanford]

Those fittings are very useful. I, too, have the pivoting kind, as well as one that describes a 90° turn in a short radius. I vaguely recall buying mine from Porter's, ten or fifteen years ago...

...but gluing something into a shutter is not the same as repairing the shutter. I still would like to know how the Devil they cut threads on the inside of a tapered cylinder; and, if a tool is available for doing it, I want one!

[RichS]

No flames today

But it was mentioned up there somewhere that this particular shutter has a flexible 3 inch extension screwed into it. The hard, angled adapters are larger and wound't fit in the small space of this shutter/board combo. The flexible extension has a much smaller tip to screw into the shutter, and just barely fits...

I think we'll either find a source for this tap, or have one made! It's more of a quest now!

[Rangemaster]

I found my tap, but it will not work in the tapered thread hole, I used it on a couple of straight holes that I have in a couple of shutters, but after fooling around it is the wrong one for a taper..

One other idea, I talked with a clock maker here locally and he said he used to use a taper tap, very simular to the ones like we have in shutters for some of his clock making, so that might be another avenue to pursue, find an old fashion clock maker.

Dave

[clnfrd]

I assume you guys have already done a Google search for tapered tap and come up with stuff like this:

http://www.knifeandgun.com/catalog/taps_186652_products.htm

[RichS]

[clnfrd]

Ah, yes!! The old tapered pipe threads! I should have suspected as much. Fred.

[clnfrd]

This is still an interesting question. Is it possible that the piece with the tapered, threaded hole was actually cast rather than drilled and tapped?

[ This Message was edited by: clnfrd on 2004-06-04 04:10 ]

[RichS]

I thought about casting. But to extend that, to make the mold, they would need a die to create the original. For the die, you need a tap I could be wrong and maybe they never did exist, but there are just so many different objects with these threads. Almost every single shutter and camera ever made for over 50 years. There must have been some kind of repair tool. You can still go down to a local auto store and buy a thread repair tool for tire valves and how often are those damaged? I have to send off another e-mail to the tap manufacturer...


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"Ya just can't have too many GVIIs"
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[clnfrd]

I think T.R. has the right idea...replace the cable release socket. If a tap does exist...it being conical in shape...it would bind after less than one turn....same as the cable release threads do when threaded into the socket.