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View Full Version : Design of No.3 shutter retaining ring needed



cyberjunkie
22-Nov-2011, 19:07
I tried to find on Ebay a cheap retaining ring for a No.3 shutter (Copal, Compur, Prontor, all of them have the same measures, AFAIK). No luck. When a No.3 retaining ring is available, the price is very high, much more than the other retaining rings made in China.
I found somebody who's willing to make a small series of such retaining rings (plus the distancer, if needed, for example with a Technika). Unfortunately he is not local to me, and asked for a design with quotes.
I work with computers (that's the source of my alias), mostly small networks, but i a have absolutely no experience with mechanical design. On top of that, i have no distancer ring for a No.3 shutter, to get the measures.

Is there a nice soul out there who would like to volunteer, and design the retaining ring + distancer?
I am not asking for an Autocad file, even a simple jpg would do. Exact quotes, easy to read, and clear design, are everything that's needed.
For somebody who's at ease with mechanical design, and who knows (or can actually measure) the right quotes, it should take 10 minutes at most.
If somebody is willing to help me, please contact me via PM.
If everything goes the right way, i'll report on this forum when the batch of rings is ready to be sold. The price should be interesting, cause a certain number will be made.
I will buy 3 or 4 pieces myself.

thanks


have fun

CJ

Jim Galli
22-Nov-2011, 20:02
There's 3 or perhaps 4 different Copal 3 rings. Early chrome is same as Compound 3. Then the Copal 3S and Black Copal 3 are different. Then some of the Nikon rings are different yet. So, I wish you luck, and if someone has a 61mm one for a Copal 3S, I need it.

domaz
22-Nov-2011, 21:03
I would just send the shutter to your machinist who is building it. He will know what to do.

Marko Trebusak
22-Nov-2011, 22:53
If you need plain Copal 3 retaining ring, I might look around the house to find one, as I asked a coleague some time agoto make me few. If it'll fit your needs, you can have it as if I remember corectly at least one is laying around somewhere.

Cheers,
Marko

Brian C. Miller
23-Nov-2011, 14:23
SK Grimes has replacement rings and flanges (http://www.skgrimes.com/products/mounting-flanges/metric-stock-flanges) in stock.

cyberjunkie
23-Nov-2011, 15:06
There's 3 or perhaps 4 different Copal 3 rings. Early chrome is same as Compound 3. Then the Copal 3S and Black Copal 3 are different. Then some of the Nikon rings are different yet. So, I wish you luck, and if someone has a 61mm one for a Copal 3S, I need it.

I have a Copal 3S, which is different, of course. All the other No.3 shutter i have share the same quotes, or at least that's what i thought... :)
When i tried to check if the ring of another lens was working, it worked.
Unfortunately i have a few No.3 shutters (Compur and Compur Electronic) which were purchased for relatively cheap in the last 2/3 years, all of them came with no rings.
Then i had a set of ring/distancer that was shipped to a machinist about ONE year ago! Every time i call i get the same answer: "I will make them soon" :(
No way i am going to ship other stuff away, especially shutters!
Then i have a Copal No.3, which houses a Komura 152mm f/2.8, but the ring/distancer set was epoxied to a Technika lensboard by the previous owner :(
Everithing is glued together, no way to easily take a few measures (that can be trusted, and used to make a series of rings!).
I still have a couple of other No.3 lenses, but one is on loan, and the other is Km. away, at my mom's house (and, IIRC, it's in a flange, on a wooden 6x6" lensboard). As soon as possible i will check the various No.3 shutters, to make sure that ALL of them have the same attachment thread. It won't be very soon, though.
I wanted to make a long story short, but some of you made questions, so i am answering...

So, to cut it short, i would need an intellegible (not pretty!) design with exact quotes, of the ring + distancer, that i will send to somebody who's willing to make a small batch at a very affordable price.

Thanks for the advice about black Copals, Jim. The newest Copal No.3 i have is on the Komura 152mm, so it's not a very recent model. Whatever, you made me curious, i will check with a vernier caliper against one of the Compur Electronic i have purchased. They came cheap because they missed the battery compartment and the retaining rings. After some time i found two battery compartments on Ebay, together with some Linhof accessories... so now i miss just the rings.
If i find an old No.3 with Compound No.3 back thread, then i will use a spare Compound flange, which i have already somewhere.
In the end, i understand that the vast majority of No.3 shutters could be fitted with the same type of retaining rings.
Do you agree, Jim? Am i missing something?


have fun

CJ