iris pins missing

[Michael Carter]

What are iris pins made of? Can I buy some?
http://3.bp.blogspot.com/_RYPVMt7kyyY/SlEpGGp3G3I/AAAAAAAAAC8/qSvRnL_4nx0/s1600/shutter.JPG

[Archphoto]

Steel, but I have seen some of yellow copper too in old equipment.
Normaly the pins are connected to the blades.....
So if you have lost one or two you have a problem.

You could try to make one or two of those pins and glue them into place with very little glue or solder them together in an emergency, but I have never tried that in my 30 odd years of being a repairman.
Replacing those blades will be the best.

Peter

[Michael Carter]

Sorry about that big picture. How about a link to my blog where it resides?
http://newlightfarmer.blogspot.com/2009/07/shutter.html

Is it actually possible to buy new blades? Would it be worth the money to send it away to Grimes to have fixed?

[Archphoto]

Grimes could be a good adress for it, you could send them an email with this photo and see what they have to say...
This is new territory to me but with patience one could repair those blades.
Unfortunately for you I am not in Holland right now, otherwise I would tell you to send them to me for repairs. (I ma back in august)
You will need a fine lathe to make the steel pins and than press-fitt them into the blades.
So they are repairable I think.

Is the lens worth it ? How much is it worth to you ?
The set-up time would be the big part, making a jig for it so you have a plate with the right hole to fit the pin at the right depth and making the pins themselves.
Press fitting and finishing is just a couple of minutes after that for each.

Peter

[RandyB]

What shutter is it? It may be cheaper/easier to just buy another one.

[RandyB]

Duh! next time I'll look before I type. I would say find another shutter.

[ruckusman]

looks as though the blades are metal, so what about some brass rod the diameter of the holes with some think walled tube that telescopes over the rod the for the larger diameter section.
Other option if you have a dremel would be to start with the brass rod the correct larger diameter and put it into a cordless drill spinning it and use the light weight cutoff wheels in the dremel to turn the diameter down. It's a kludge that I've used that mimicks a tiny lathe to some degree.

Very small and fiddly to work with, but by the looks of things, you're not perturbed in that arena.
Then you could attach it with soft solder applied with a small hot air pencil if you don't have a soldering iron handy

[Archphoto]

Regular solder as used in electronics will not last and will not hold.
The best thing you can do is making those pins and heat them up and then press the top part like a rivet.
But you will need the set-up and the equipment for it.

Peter

[Michael Carter]

The lens is a Unicum 12 inch f 10. It came with a junker parts folding camera, a Pony Primo No. 6. The camera was a 5x7 and did not have a back. The lens has two pistons and is very nice looking. It is now wide open and will have to stay that way for the present. The shutter works. It looks a lot like the one on the 4x5 Primo in my blog but larger. I like them and will fix it somehow someday or I'll send it to you Peter. I think it is worth making it function corectly.
The dial at the top has click stops for T B I 2,5,25,50,100 and they are all different speeds.

[Archphoto]

The lens is welcome at my place when I am back in Holland, please send me a PM somewhere in August so I can give you my adress.

Peter

[Jon Wilson]

I don't know if this unicum shutter would work for you and BTW I am not affiliated with the seller, but you might look at this:
http://cgi.ebay.com/Antique-Bausch-Lomb-UNICUM-Brass-Camera-Lens_W0QQitemZ230354855201QQcmdZViewItemQQptZFilm_Cameras?hash=item35a2382521&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1234|293%3A1|294%3A50

Or if the above link does not work: ebay Item number: 230354855201

Jon

[Michael Carter]

http://newlightfarmer.blogspot.com/2009/07/unicum-lens-iris-part-needed.html

That lens is more and more interesting; I just fixed it again, but with pencil lead and super glue. One blade was removed and placed on 1/4 inch graph paper. Have a look. Three blades with two pins each are needed; one pin on each side on each end.
Focal length doubles without the front element. It has two barrells and all four parts interchange; it also fits onto a different similar lens...

PM t/c thanks.

I'll try to get that one above, thanks for the link. Hmmm, mine does not have a scratch.

[Jim Galli]

One approach might be to obtain a brass screw #4 #5 #6 whichever is correct diameter of the pin, then mill or sand the head until it is paper thin, and remove the shank to the pin length. That would give you a ridge on the verso that would help immensely with some suitable resin type glue and shouldn't interfere with the other blade next to it.

[GPS]

http://newlightfarmer.blogspot.com/2009/07/unicum-lens-iris-part-needed.html

That lens is more and more interesting; I just fixed it again, but with pencil lead and super glue. One blade was removed and placed on 1/4 inch graph paper. Have a look. Three blades with two pins each are needed; one pin on each side on each end.
Focal length doubles without the front element. It has two barrells and all four parts interchange; it also fits onto a different similar lens...

PM t/c thanks.

I'll try to get that one above, thanks for the link. Hmmm, mine does not have a scratch.

I'm puzzled - why do you care about the scratch on the lens when you need just the shutter blades? :confused:

[Michael Carter]

I'm puzzled - why do you care about the scratch on the lens when you need just the shutter blades?

I'd have to buy that lens just to get an iris blade? No way. I'll use this one at one f stop as is if I have to. Surely someone has already gone through this and has all ready accumulated lots of busted lenses for parts.

[GPS]

You can wait for another Unicum shutter. They go sometimes for even just 13 $ especially those with bad lenses or bad shutters themselves.

[GPS]

By the way, how do you want to get around the problem of their non light tightness once "exposed" by Jim Galli on this forum? Just curious...

[Michael Carter]

By the way, how do you want to get around the problem of their non light tightness once "exposed" by Jim Galli on this forum? Just curious...

what's that?

two other similar lenses are on the way

I searched but found 400 for Jim. Do you have a more direct link?

[GPS]

Sorry, I don't have the link handy. Basically the problem is that the shutter blades are made from a material (that time "plastic") that leaves red light going through. You can see it when you look through the lens with a closed shutter at the Sun - you'll see dark red Sun shining through. Thank Jim for the discovery...

[GPS]

It's described in the thread "Old brass shutter"...

[Tim Deming]

I've fixed a few irises with this problem. Mostly large barrel lenses, where finding a replacement iris or blade would be impossible.

If you have the pins that fell out, this makes things much easier. I sanded these down a bit on the bottom, and tried to sand the iris blade a little too. then it was just some 2-ton epoxy to glue the pins back on. I've found that using extra epoxy, pooled around the pin, top and bottom, helps a lot in terms of making sure the pin is not knocked off again. In the lenses I've worked with, i.e. old ones, I've found there is a reasonable amount of play/free space where the pins slide -so the extra epoxy does not cause a problem.

If you dont have the pins, I've successfully used small metal screws, or even threaded bolts that closely fit the hole diameter. These have been left over parts from other shutters/cameras, etc. If you are lucky, you can find a small metal bolt with a head the size of the pin, with a few threads on it (cut off the rest of the bolt with a dremel) you can use to screw into the hole. I would epoxy these on as well.

as mentioned above, solder wont stick to the iris blades. Many are ceramic or plastic or paper. Steel/metal ones are treated or hardened in a way that solder wont stick. Be careful also as the iris blades are usually very brittle. I dont have equipment to press pins back into the iris blade hole and so havent tried this, but usually the hole is cracked or enlarged, so this wont work in that case, unless you use a bigger pin. Epoxy adheres well and holds up under normal use.

cheers

Tim

p.s. in case you need to, it's not too difficult to make new iris blades from thin sheet spring steel. check mcmaster-carr for this. it can be difficult to drill holes in this without special equipment.

[Michael Carter]

Two other lenses arrived in perfect shape; I think I'll sell the ones that do not function properly instead of trying to fix them myself or send them away.