C.P. Goerz Extra Rapid Lynkeioskop Serie C. no1 > flange diameter?

[Ron (Netherlands)]

Recently I got the C.P. Goerz Extra Rapid Lynkeioskop Serie C. no1 albeit without a flange.
From what I have measured the thread pitch is M0.7 or TPI 36. Further the diameter of the screwmount on the barrel is 37,92mm. So I guess a flange with a diameter of about 37,30mm might fit, but not sure of course. Before buying some of these flanges I would like to have a more specific measurement so if there are fellowmembers that might have this same lens, I would be most grateful if they could provide a measurement of the diameter of their flange.

thanks
Ron

 

[awty]

I dont have that particular lens, but I have a couple that look like the flanges are around just under 38mm (only have a ruler) and the flanges are interchangeable. So must be a common size.
Have you tried any you already have?
Both of mine are English.

 

[Ron (Netherlands)]

I dont have that particular lens, but I have a couple that look like the flanges are around just under 38mm (only have a ruler) and the flanges are interchangeable. So must be a common size.
Have you tried any you already have?
Both of mine are English.

Thanks Awty, and yes I've tried all my spare mounting rings (about 40 in total) Btw it seems to be a continental size - Goerz was a German producer (most of my mounting rings are also imperial and don't fit: have threads that are too coarse).
It is indeed under 38mm, but a few mm makes a big difference in case of 'little' lenses. I have messured the size of the thread on the barrel with a digital calliper. and a thread gauge. From the gauge the best fit is the M0.7, but very near comes the TPI 36.

 

[Ron (Netherlands)]

A little update: still no matching flange found; however I found which diameter the flange should have to provide a decent fit. I tried a retaining ring from a Compur 1a shutter and it fitted nicely. The retaining ring has a diameter of 37.64mm.

Different from the lens which as a thread pitch of M0.7 the retaining ring was close with a pitch of M0.9. Since the retaining ring must stay on the shutter, I'm still searching for a matching flange/mounting ring which ideally should have these specs:
a thread pitch of M0.7 (or TPI 36) and an inner diameter of 37.64mm.

 

[nosmok]

I have good luck threading lenses or shutters directly into a wooden lensboard. The trick is to make the board out of softer wood than normal (I laminate 2 layers of craft basswood with the grain 90 degrees apart). Cut a center hole with the nearest hole saw, expand with sandpaper until you can just screw in the lens or shutter flange.

 

[Ron (Netherlands)]

I have good luck threading lenses or shutters directly into a wooden lensboard. The trick is to make the board out of softer wood than normal (I laminate 2 layers of craft basswood with the grain 90 degrees apart). Cut a center hole with the nearest hole saw, expand with sandpaper until you can just screw in the lens or shutter flange.

thank you Nosmok, your solution might indeed work. However the lens in question is part of a restoration project: I'll try to restore a camera as close as possible to its original state. Therefore I would still like to find a matching mounting ring or flange.

 

[BrianShaw]

I have good luck threading lenses or shutters directly into a wooden lensboard. The trick is to make the board out of softer wood than normal (I laminate 2 layers of craft basswood with the grain 90 degrees apart). Cut a center hole with the nearest hole saw, expand with sandpaper until you can just screw in the lens or shutter flange.

I've done this a couple of times with great success. It is barely noticable that there is no flange. And when a flange is located, the hole can be enlarged accordingly. Perhaps this is an ideal intermediate step for Ron's restoration project? All of my experiences have been with fairly light lenses. It seems to me that this is a perfect solution for the lens under discussion.

 

[Ron (Netherlands)]

I've done this a couple of times with great success. It is barely noticable that there is no flange. And when a flange is located, the hole can be enlarged accordingly. Perhaps this is an ideal intermediate step for Ron's restoration project? All of my experiences have been with fairly light lenses. It seems to me that this is a perfect solution for the lens under discussion.

Many thanks Brian, indeed as an intermediate solution this will work for this lens, since it is quite a small lens: it only covers 9x12 cm plates.