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Sweep
10-Dec-2017, 08:26
I have just bought a Nikkor W 360mm f6.5 in Copal 3 shutter which came mounted to a thick wooden Deardorf board.
I think the lens will just about fit on a Linhof board but i need to make a Copal 3 spacer ring to make up the difference between the old wooden board and the modern cast aluminium Shen Hao boards as the ring was missing.
I do have a spacer ring on my Apo-Symmar 240mm which i could measure but, so i don't have to strip it down, wondered if anyone had the correct dimensions of these rings so i can make one up on my lathe.
It is not the shims i am looking for, just the spacer which goes under the threaded assembly ring as shown on this ebay listing
https://www.ebay.co.uk/itm/Copal-Compur-Prontor-3-Shutter-Retaining-Ring-Schneider-Nikkor-Rodenstock-Lens/282670913091?epid=2266952905&hash=item41d07fd643:g:3aoAAOSw1KNZyZI6

thanks ...Sweep

Dan Fromm
10-Dec-2017, 09:02
Not to be a complete idiot, but since you have the big Nikkor why don't you (a) try mounting it as is and (b) if that fails measuring how thick the spacer will have to be? You have a lathe, you should be able to measure.

If you meant retaining ring (threaded internally, and that's what's offered in the link you posted), measure the rear tube of the #3 shutter the lens is in. FWIW, the Nikon brochure says it is M62x0.75. Go here http://www.skgrimes.com/products/new-copal-shutters/standardcopals to find mount threads for #3 and #3S Copals, the info will help you decide which you have.

Sweep
10-Dec-2017, 09:26
Hi Dan,

No problem. The threaded nut has a shoulder on it which butts-up to the back of the plate and sandwiches the spacer to the back of the lens body. If you don't have the spacer ring then the threaded nut can't clamp up and a thin plate just hangs loose.
The spacer thickness needs to be, therefore: Threaded nut overall length - thickness of shoulder - thickness of new plate + a 'bit' to ensure the nut nips the board.
This isn't a problem with the thick wooden boards as they are, well, thick. I suppose i could make the spacer as wide as the old wooden board, about 9mm, but just wondered if anyone had the correct dimensions to hand.

...Sweep

Tin Can
10-Dec-2017, 09:37
eBay sells them for $20

Sweep
10-Dec-2017, 10:58
I know, Randy. My first post gave a link to an ebay seller.
What i need to know is the dimensions so i can make one for $0

Jac@stafford.net
10-Dec-2017, 11:21
I fail to understand why you cannot simply measure and make it.


What i need to know is the dimensions so i can make one for $0

Aw, just measure it and be sure yourself.

Sweep
10-Dec-2017, 12:18
Jac states, "I am not going to spend my time if you won't make the effort to be certain"
But Jac, if you don't know why bother responding to the post???

So, i can take it from the replies that the answer most people are giving is "No, i don't have the dimensions."
There's no shame it not knowing. I don't know which is why i asked but, if you actually read my first post, I said was that i would prefer not to strip down my 240mm to measure the thing so "wondered if anyone had the correct dimensions"
I take it that no-one does know so i will go ahead and strip the 240mm
I bet i could up my post count if i responded to every post saying that "I don't know."

Jac@stafford.net
10-Dec-2017, 12:23
Jac states, "I am not going to spend my time if you won't make the effort to be certain"
But Jac, if you don't know why bother responding to the post???

I could measure my spacer, but that is something you can do.

Sweep
10-Dec-2017, 12:54
I could measure my spacer, but that is something you can do.

Sounds like a plan, Jac. Sounds like a plan.
I will see if i can get it done tomorrow night and will post the dimensions on here

...Sweep

Jac@stafford.net
10-Dec-2017, 14:38
Sounds like a plan, Jac. Sounds like a plan.

I feel better knowing that you will measure because then you are the authority. Good luck!