Damaged aperture - is it fixable

[pjd]

I tried to repair aperture blades on a shutter with a similar problem, I didn't find a way to get the metal stub to stick in the blade. I remember trying a dab of thread locker, that didn't work and I didn't have anything else that felt worth trying. That was a 20s or 30s dial set shutter. On the other hand, I did manage to replace a set of blades in another dial set shutter, the blades were intact but a couple had jumped out of place somehow (heavy impact at some point, possibly). It took me a good couple of hours to get the blades back in, the first 17 or 18 blades are simple enough, the 19th was a nuisance but getting the final blade in place was tough. A few times during that process I wondered if there's a secret knack to replacing the blades, I suppose the answer is lots of practice and small fingers.

Before anyone points out I shouldn't have bothered; I received both lenses in that condition - and a professional repair would have cost more than a replacement lens. I hope Randy can fix that lens, I'll be interested to hear if there are any tips about getting the stub to stick in place in an aperture blade.

[Randy]

The blades are plastic, and about 6cm end to end. The pins are brass, and about 2mm in diameter and height.





I may just try as has been suggested - leave the damaged blades out and try it with just 18.

[Jac@stafford.net]

I have a lens with a totally whacked aperture - it has broken blades stuck in an oval shape. I thought it might have some interesting qualities - it does not. The lens is on the bench awaiting a postmortem.

[Tin Can]

Looks like it was originally peened.

The blades are plastic, and about 6cm end to end. The pins are brass, and about 2mm in diameter and height.





I may just try as has been suggested - leave the damaged blades out and try it with just 18.

[LabRat]

If the pin is almost a snug fit, you can try superglue gel or thin, just keep it off the pivot pin moving surface, and it is beneath the surface of the iris blade...

Note that if there is a blade issue, it is usually because there is a resistance or binding of the blades, inner rings, or the pivots that don't allow the blades to move freely... Check for migrated lubes, oxidation etc...

If you try to fix, make sure the pin comes perfectly straight off of blade or blade will not sit correctly and repair point will be strained...

Steve K

[neilt3]

I don't know about repairing your existing aperture , but would it be possible to replace it as a unit with one of these off ebay ?
https://www.ebay.co.uk/itm/New-4-60M....c100005.m1851

[domaz]

I'm ashamed to say that I've fixed a broken aperture that was missing pins by sculpting new "pins" out of JB Weld. It works better than you would expect. The lens has been working for a year or two now with no issues.

[Tracy Storer]

Wollensak made a lot of lenses, and I mean a lot. Maybe you can find another (damaged / broken / cheap) lens that uses the same size aperture blades.

[Randy]

Good suggestions folks - I'll keep an eye out for another parts lens, but I suspect that as old as these things are, pins are going to fall out. I may try the re-manufacturing the pin from JB Weld or epoxy. Heck, I might be able to trim down a wooden or plastic tooth-pic for a pin - just so darn small.

neilt3, I like the aperture you linked, but I have no idea how one would adapt such a thing to the existing lens barrel.

[LabRat]

If you have the old pins, you have the pins already... I wouldn't make them, as they need to be smooth, round, and perfect as possible... A considerable amount of force pivots over these, so they need to be bonded well, and no drag from the pivot rotation...

If you need pivot material, a good hobby or model train store has different metal rods so look there...

When bonding the rod to the iris blade, it's very good to make a jig of a very flat material with a precision hole for the pin to align it precisely...

For the heck of it, just price Grimes for the job of re pining it as suggested, if the blade is out, it shouldn't be too much to do, and it's easy to screw it up...

Steve K