Best way to combine lens parts

[hoffy]

OK, here is the scenario. I have a 180mm Koni-Omega lens that has a bit of a problem. The aperture blades appear to be jammed solid and the shutter doesn't reliably fire. There is also a second issue, which appears that someone had moved the rangefinder focussing pins, as when I attached the lens to the camera, the focus was way out.

Luckily, I found a replacement assembly on Ebay, which I bought. The previous owner had stripped the glass out and was using the shutter/aperture assembly for a home made film camera. From what I can see, everything works fine, its just missing the lens barrel and all the other glass from the camera end. This new assembly also has the range finder pins which (from my rough measurement) look to be in the right spot (as described in the repair manual)

Should I:

A) just remove the parts needed from the newer assembly and put them in the old broken assembly?
B) Keep the new assembly fully together, remove the old glass and lens barrel from the old assembly and assemble it together?

My preference is B, but my concern is altering the distance between the front elements and the rear elements. Does anyone else have any advice on which way I should go?

Cheers

 

[dehk]

I'll go with B because its much easier, if everything else works with the replacement, less work and less chance to f up. If B fails than put both cameras together and make it work.

 

[hoffy]

Thanks.

 

[Dan Fromm]

All you have to do is unscrew the cells from the knackered shutter and screw them into the good one. They come out as units, one front cell, one rear cell. Don't disassemble anything else. Pull the hood forward and then you'll be able to get a good grip on the front cell.

If you try to move parts from the knackered shutter to the good one, you'll have to reassemble the aperture control and shutter linkage. Fiddly work. Better just to move the cells.

All of this assumes that y'r eBay find is a shutter for a 180. If it isn't for a 180 swapping cells is not a good idea, the lens won't focus to infinity in a shutter for a shorter lens.

If it isn't clear to you, per Greg Weber (you might call him for advice, he's very approachable but, alas, not always right) all K-O lenses are in Copal #0 shutters.

 

[hoffy]

Thanks. Yes, the shutter is from the 180

Cheers

 

[NormanV]

I can't give any answers but am interested in this thread as I have a similar problem with my Fuji GW690. I have bought a new front lens group but found that when installed it gave worse results than the original. It seems that I need to place shims to space the elements further apart or I have a big problem in getting them closer. Can anyone help?