Help with Yashica Electro GN 45/1.7 lens disassembly.

[funkydog]

Hello everyone. I need some guidance with disassembling the big black block in the 45/1.7 lens from a Yashica GN rf. I've looked on the net and it appears that no one else has taken the lens off a Yashica rangefinder to use on another camera.

As you can see from the photo taken with the lens temporarily clapped on to a M mount digital camera that the lens has much potential.

I've been able to slide open the shutter blades but that's as far I can go from the front. There are protrusions on the back that need to be removed. I've tried but cant loosen the rear lens assembly.

So the question is, what's next?

No living Yashica GN's were harmed. I bought this camera ten years ago from a seller who advertised it as dead and for parts. I've been waiting for technology to catch up and now there's finally a digital camera that I can use with the lens.

Click through for a larger pic on Flickr.

 

[nparsons13]

Check Jackslai's series of photos at http://www.flickr.com/photos/xy9z/sets/72157623833920480/with/4512530402/. It may contain some hints, although there's no text to explain what's going on.

 

[funkydog]

Thanks for the very useful link. The pictures make sense as I've done some of the things he's done and I can see what else I need to do. As I suspected, the rear lens assembly hides a retaining ring that holds the black frame to the midsection containing the aperture and shutter blades. The double set of retaining rings for the rear lens assembly are jammed tight from paint and decades of grit. They made from thin, easily deformed, brass with tiny tool notches.

Having peeked into the guts of the GN, I'd say the camera is a work of art and a disaster at the same time. The Yashica designers must have prided themselves on creating the most internally complex electro-mechanical auto exposure camera of the period. The assembly line workers back in the day really BUILT the camera. The camera would likely also have been a nightmare for repairmen who used to do component level work back in the day. Today's digicams, in comparison, are likely to be assembled with the same finesse and panache found in Mcdonalds sandwich assembly.

 

[farlymac]

I've got a couple of dead Electros laying around that I may transplant the lenses from some day. But first I need to get a camera that would be worth doing that with.

PF

 

[b1bmsgt]

I have disassembled literally hundreds of Electro's and never had a problem getting the rear lens group to unscrew. I have a tool that has points that engage the small notches on the lens ring. They always come loose rather easily.

Just FYI...

Russ

 

[funkydog]

It's a right tool for the right job thing. Took it to the repair guy. He was sufficiently amused to assist without charge. Took him a couple of minutes to loosen the three rings. He did say they were very stiff. So now I have a working 45/1.7 to mount on another camera.