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

**Ron (Netherlands)** · 26-Aug-2023, 03:36

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

**arri** · 28-Aug-2023, 04:18

Originally Posted by 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

HI Ron,
I looked in my stock but I don´t found a lens with this thread.
But I can offer to turn a ring for your lens. I offen did it for LF photographers and a small ring like this costs not really much.
For this you have to send the lens to me to take care that it will really fit.
I live in Germany and maybe the shipping charge are acceptable extra costs.

**Ron (Netherlands)** · 30-Aug-2023, 02:21

Many thanks Arri for your very kind offer. Since my question is just recently posted and we are now in the holiday season, I'll would just like to wait a little longer to give fellowmembers (who might be on holiday) give the opportunity to give a response if they have the same lens. If there will be no further responses, I would like to make use of your kind offer and we'll be in touch.

**Ron (Netherlands)** · 13-Sep-2023, 14:34

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.

**peter brooks** · 15-Sep-2023, 00:57

Could this be one and a half inch at 36 TPI?

As you are in the EU I'm sure Jose at Custom Photo Tools could help (I have no connection apart from being a happy customer - he has done excellent custom work for me). You could even send him the lens.

Good luck!