Just got this and one question comes up. The rear group evidently can only be removed from the barrel mount after removing the diaphragm, as it unscrews FORWARD. Right now the group will only rotate about a third of a turn, as the group cup hits the rear of the diaphragm basket on the way forward, or bottoms against the threads on the way backwards. I don't intend to pull the diaphragm to study it further, as everything is working OK anyway.

The question is, is the cell supposed to be tightened inwards or outwards to be positioned correctly. I'm thinking that it has to be run up against the back of the diaphragm basket, which hopefully positions the rear cell correctly with the front cell. This impression is reinforced by the fact that if you try to back it out it it does not seem to cleanly come up against a firm surface, and feels a bit spongy when it runs out of travel.

Quote:

On 2006-02-24 17:31, disemjg wrote: Just got this and one question comes up. The rear group evidently can only be removed from the barrel mount after removing the diaphragm, as it unscrews FORWARD. Right now the group will only rotate about a third of a turn, as the group cup hits the rear of the diaphragm basket on the way forward, or bottoms against the threads on the way backwards. I don't intend to pull the diaphragm to study it further, as everything is working OK anyway. The question is, is the cell supposed to be tightened inwards or outwards to be positioned correctly. I'm thinking that it has to be run up against the back of the diaphragm basket, which hopefully positions the rear cell correctly with the front cell. This impression is reinforced by the fact that if you try to back it out it it does not seem to cleanly come up against a firm surface, and feels a bit spongy when it runs out of travel.

Are you sure? I ask because I've taken a fair number of lenses in barrel apart, and every one of them has had a rear cell that's unscrewed to the rear. Many have had rear cells that could be dismantled farther, but with each of them the first step has been to remove the rear cell as a unit from the barrel.

The same is true of every lens I've had in shutter, including a 12"/5.6 TeleOptar. The rear cell unscrews from the rear of the shutter and then, sometimes, the front group (facing the diaphragm) can be unscrewed from the barrel the rear cell is in. And the rear group (facing the film) comes out too.

Good luck, look at it again,

Dan

I'm as sure as I can be without actually disassembling it, through the front. I've never seen one like this either. I just finished mounting it on a Pacemaker board, and when the weather gets more inviting I'll try it out. I'll try it with the rear cell run inwards.