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mikec
1-Jul-2016, 08:22
I have just acquired a Cooke Series XV in a barrel mount. Unfortunately I do not have the mount flange. I have been trying to measure the mount thread and also the element threads to see if they could be dropped in a shutter but I am not sure if my measurements are good. I have a thread gauge for Whitworth and metric scales. The Whitworth templates are marked in xxG rather than TPI and I don't know how to convert them. If anyone can do that I would be grateful for the translation.

Flange Mount thread: 2,24in x 24G 57,1mm x 1,0mm
Rear Element thread: 2,04in x 30G 52mm x 0,8mm
Front Element thread: 2.35in x 40G 59,6mm x 0x5mm

I do not think this is a metric threaded lens as the metric gauge templates are just close fits, whereas the Whitworth templates are a prefect fit. That makes sense as it is a 50s lens (my interpolation of VM data), before the Brits had gone metric.

Can anyone point me to a technical drawing of this lens with thread data please?

Another question: The diaphragm ring is stiff and needs a CLA. I can probably have SKGrimes fix both issues and have used them in that past but they are over the pond and far away. Does anyone know of a European shop that can do as good?

Dan Fromm
1-Jul-2016, 17:34
Re service in France, see http://www.collection-appareils.fr/general/html/reparateurs.php and ask on the French LF forum www.galerie-photo.info. I'd go to Gérard Metrot www.ateliergms.com

mikec
1-Jul-2016, 22:59
Re service in France, see http://www.collection-appareils.fr/general/html/reparateurs.php and ask on the French LF forum www.galerie-photo.info. I'd go to Gérard Metrot www.ateliergms.com

Thanks for that.

mikec
2-Jul-2016, 01:30
The Whitworth templates are marked in xxG rather than TPI and I don't know how to convert them. If anyone can do that I would be grateful for the translation.

Flange Mount thread: 2,24in x 24G 57,1mm x 1,0mm
Rear Element thread: 2,04in x 30G 52mm x 0,8mm
Front Element thread: 2.35in x 40G 59,6mm x 0x5mm

I do not think this is a metric threaded lens as the metric gauge templates are just close fits, whereas the Whitworth templates are a prefect fit. That makes sense as it is a 50s lens (my interpolation of VM data), before the Brits had gone metric.



I counted the thread pitch and as far as my tools (no imperial ruler) are able the G seems to be synonymous with TPI. Why they gauge manufacturer didn't just put TPI defeats me.