QL17 rear element

[servojohn]

I picked up a QL17 which looks nice, but has issues. The major problem appears to be an aperature that doesn't open consistently to the wider settings. I did manage to remove the front element, and was able to give it some ronsonol. The problem is a need to remove the back element to clean things from the backside. The QL17 has two lockrings, not three, like the GIII. The two lockrings are not separating, and the outer ring is too big to clear the chamber.
Is this inner ring a left hand thread? Either way, it is very tricky trying to get a grip on it to loosen without loosening the outer ring. :bang:

Thanks for any help!

Best regards,

John

 

[servojohn]

Thanks, that is what I remember from previous searches. How to hold the outside one while trying to loosen the inner one is going to be a trick, especially since the notches on both rings pretty much line up. Plus, the outer ring wasn't very tight at all in the first place.

Best regards,

John

 

[servojohn]

Yes, it's one of the larger ones, not a GIII size. The lens barrel parts look different too.

John

 

[servojohn]

Yes, that works. Got the lens assembly out, removed the "shroud", and then the rear element. Now the gist of the main problem appears-it looks like the aperature control ring doesn't engage the aperature blades-it just moves smoothly through the range, no clicks, no movement of the blades to the appropriate f stop. This seems a bit odd, as the camera would attempt to stop down when running through the advance/cocking cycle, although incorrectly, and rarely to 1.7. I suspect the control ring has a pin that is not sitting in the right spot in the lens.
I suspect now I have an excersise in futility, if the warnings on dismantling a Canonet lens further ring true.
Time to ship it to you?

Again, thanks for the help!

John

 

[servojohn]

In other words, shower time!?

Just to be clear, if I have the front and rear elements out, so that the shutter blades and aperature blades are exposed from either side of the lens, I should be able to flush ronsonol through these mechanisms and hopefully get the aperature to free up. The shutter is already good again, responding to some earlier ronsonol treatment.

Best regards,

John

 

[servojohn]

After giving the lens barrel assembly a good shower yesterday, I came back to it this afternoon, and I'm afraid the aperature still isn't working right. It was closer to working right when wet with ronsonol(yet still not 100% correct) than dry. Also, the f stop control ring still doesn't seem to engage properly when dialing down to the wide open stops-it just stays at whatever setting it was at before changing direction on the ring to dial it down to 1.7. The aperature will open up to 1.7 with a little nudge when the shutter speed is set to B, but really won't go more than halfway on its' own.

Best regards,

John

 

[Kim Coxon]

Hi,
If it is very dirty, this does happen because the fluid can "dilute" the muck but not wash it away. I put fluid on with a very damp Q-Tip and wet it well. Then use a dry one to absorb the excess and hopefully the disolved muck. Let it dry and try again. Repeat as many times as needed. With one QL19E, I nearly gave up but after about 20 washings, it came good. The same is most likely happening to the aperture blades.

Kim

After giving the lens barrel assembly a good shower yesterday, I came back to it this afternoon, and I'm afraid the aperature still isn't working right. It was closer to working right when wet with ronsonol(yet still not 100% correct) than dry. Also, the f stop control ring still doesn't seem to engage properly when dialing down to the wide open stops-it just stays at whatever setting it was at before changing direction on the ring to dial it down to 1.7. The aperature will open up to 1.7 with a little nudge when the shutter speed is set to B, but really won't go more than halfway on its' own.

Best regards,

John

 

[servojohn]

Anyone try an ultrasonic cleaner?

John

 

[Kim Coxon]

Most pro repair men use them but for it to work well, I think you need to clean the components not the whole mech.

Kim

Anyone try an ultrasonic cleaner?

John