Mamiya RZ67 Pinion Shaft and nuts

[fdelconte]

Dear all,

this is my first post on Photrio. Though, I've been reading and learning a lot in the last years.
I have a problem which I am not able to fix and I hope to find some support and help here. I hope to be clear because english is not my native language.
I broke the pinion shaft of my Mamiya RZ67 and I've replaced it with another one, purchased at Hervé Thurel's workshop in France.
Unfortunately the diameter of the new pinion shaft's thread where you tighten the focusing knobs is different from mine. Despite the pinion shaft does its job right, it is a different "model". It is slightly wider. With a drill I've then broadened the holes of the knobs but now I am not able to fix them with the nuts. Because the nuts I have does not fix the thread - which is 5 mm wide.
I've then been looking for the right nuts but it seems to be a very difficult task. I've been in several shops and workshops, I've been searching though the internet and I was told that these parts used in photographic equipment are not easy to find. This morning I've just received a new pack of nuts but these are not working as well.

Can someone give me any information about it?
Did someone have the same problem?
Do any of you have these nuts to sell?

I would really appreciate any suggestion because I really would like to fix my camera.

Thanks a lot to everybody,
Best
Francesco

 

[Mamiya_Repair]

Around 1986, Mamiya used a different focus shaft with large threads for the focus knobs. The previous threads were 4mm and the newer shafts used 5mm nuts. The reason why you are having a problem finding the correct nut is that contrary to most metric threads which are coarse, Mamiya used 5mm fine thread on the focus shaft ends. In your case, you will need to replace your focus knobs with the correct, large size threads and nuts.

 

[fdelconte]

Thanks a lot for your reply. Do you know, beside Ebay and other e-commerce, where I could find the right focus knobs?

 

[Mamiya_Repair]

Thanks a lot for your reply. Do you know, beside Ebay and other e-commerce, where I could find the right focus knobs?

If you contact me through the website link in my post I can help you out.

 

[fdelconte]

Hi, apologize for the late reply. I fixed the problem, at least for the moment. I forced a bit the nuts and they worked eventually, and with a 3D print I've made the focus knobs. Thanks again for your help