Stiff aperture ring - Any fix?

[Scott --]

Hi, all -

One of the lenses I recently got is an old Kodak #33 7-1/2" f/4.5 anastigmat in barrel. The glass is coming apart and cleaning up nicely, and I'm prepping the pre-Anny Speed for testing it out. But before I reassemble the lens, I'd like to take care of the really stiff aperture ring. But I'm not sure what to do.

Anyone know of a fix, without removing the blades, for a sluggish aperture ring?

Thanks,
Scott

[eddie]

i am no expert!

you could try and clean it with some kind of soapy water and a brush. or just stick it in soapy water and work it back and forth. after you get all the gunk out you may need a drop or two of oil. but be careful not to get he oil everywhere.

i opened up an old lens and there was a tiny tiny screw holding on the aperture ring. i was able to remove this and get inside a bit more and free it all up.....tough to explain without the barrel in my hand.

you are right about dislodging the aperture blades...makes for a few hour nightmare reinstall.
good luck. keep us posted

[Scott --]

On a suggestion: A few drops of xylene on the outside of the barrel between the aperture ring and the housing, and it rotates like butter! Nothing got inside, and I don't have to disassemble anything...

[FilmIsNotDead]

With the cells removed first determine if there is a mechanical issue... damage or obstruction. Then clean with Ronsenol lighter fluid working open/closed (slowly - don't force them)... this should free it up. Then drain, carefully blow out the excess fluid, and allow to air dry thoroughly with the blades fully open. If that doesn't fix it then there is probably a mechanical problem you can't easily see.

[Darren Kruger]

Anyone know of a fix, without removing the blades, for a sluggish aperture ring?

It might just be the outside adjusting ring. I had a lens where there was all sorts of crud there. I just removed the outside ring via set screw and cleaned it up and it turns much better now. I didn't need to remove the aperture blades or risk getting any fluid on them.

-Darren

[Ernest Purdum]

MY experience is the same as that of Scott and Darren. I don't think the blades are apt to have anything to do with this sort of problem.

[Pete Roody]

On a suggestion: A few drops of xylene on the outside of the barrel between the aperture ring and the housing, and it rotates like butter! Nothing got inside, and I don't have to disassemble anything...

Starrett Tool & Instrument Oil also works.