Stripped copal retaining thread

[watanabe`]

Thanks for all the advice will give sk a call.

Also, I have one of the square metal lenswrench stamped spanners, however the lens in question had one of those small set screws to prevent it from spinning in the lens board. When I received it thelens had some wobble on the board so I took it off. Found 2 grooves in the hole on the board that looked like one of them would hold the screw so realigned the front element with that and started cranking on the ring when after a turn it wouldn't go any further. Stupidly thought I was pulling the lens into it's proper place when in fact I was just pulling the threads out. Let that be a lesson to you that you probably already knew: don't force anything camera related when it won't move.

[Ian C]

With respect to #7

Usually the shutter body is steel and the ring is aluminum.

I examined my late model 135mm f/5.6 Nikkor W to determine what metal the threaded mounting sleeve of its Copal 0 shutter is made of.

The mounting sleeve is finished black except for the unfinished end. That’s machined square and left unfinished to form a seat for the shoulder of the rear unit.

I brought a small magnet slowly to the end and outside diameter of the sleeve until the magnet touched. I tried this in a number of places. I couldn’t detect any magnetic attraction.

Austenitic stainless steel is known to have little or no ferromagnetic attraction, but the unfinished end doesn’t look like steel or stainless steel. It looks like aluminum.

Older shutters might well have steel shanks, but this Copal 0 shutter appears to have an aluminum mounting sleeve.

[Neanderman]

(D)on't force anything camera related when it won't move.

Don't force anything, period, when it won't move. It is a sign that something is wrong.

Ed, son of a mechanical designer.

[jeffreyg]

If all else fails or is not feasible could he get the next larger size retaining ring and lubricate it and the lens board and VERY carefully place a bead of epoxy resin around the shutter threads then place the larger ring. If all works well then he will have made a new set of threads.

http://www.jeffreyglasser.com/

[paul_c5x4]

Turning a 0.5mm thread requires specialized tooling that most machine shops won't have.

If by "specialized tooling", you mean full form indexable carbide inserts, you'd probably be right. However, any decent machine shop worth their salt should be able to grind a cutting tool to do the job - For a 0.5mm pitch, a stub of 1/8" square HSS would be ideal.

If the OP had been closer to me, I'd have offered to do the job for him.

[Jon Shiu]

Thanks, you are correct. I don't think he could have stripped steel threads with a small aluminum ring.

Jon

With respect to #7



I examined my late model 135mm f/5.6 Nikkor W to determine what metal the threaded mounting sleeve of its Copal 0 shutter is made of.

The mounting sleeve is finished black except for the unfinished end. That’s machined square and left unfinished to form a seat for the shoulder of the rear unit.

I brought a small magnet slowly to the end and outside diameter of the sleeve until the magnet touched. I tried this in a number of places. I couldn’t detect any magnetic attraction.

Austenitic stainless steel is known to have little or no ferromagnetic attraction, but the unfinished end doesn’t look like steel or stainless steel. It looks like aluminum.

Older shutters might well have steel shanks, but this Copal 0 shutter appears to have an aluminum mounting sleeve.

[watanabe`]

Just to let you/anyone else who has this problem know: Bob at precisioncameraworks was able to take care of it for cheap. Apparently he didn't need to resort to putting it on a lathe and could use a chaser to repair the threads.

Thanks for the help