Old summar - how to stop it rotating?

[Gazzah]

I just got hold of an old summar 5cm f2
I want to use it on my M5 so I want to stop it collapsing, also the aperture ring is so stiff that it causes the lens to rotate when changing f stop.
Is there a recognised way to fix either of these issues?

I could wrap tape round the barrel to stop the collapse, but how to either lossen up the aperture or stop the barrel rotating...?

TIA

Gary H

 

[johannielscom]

Sounds like a job for a skilled repair man.

The barrel should 'lock' into place by two small tabs at the rear of the tube that slide under two small ridges. Look from the rear and you'll see what I mean. Are you extending the barrel far enough for that to happen? If it's wobbly when extended, the felt inside the mount has become too dry. Two or three small drops of oil will make the felt swell a bit again and wobblying might become less.

Loosening up the aperture is tricky on a Summar, there is very little room next to the aperture ring and I'm sure the ring goes straight to the aperture so naphtha is out of the question to loosen that gummed grease, it could migrate unto the aperture blades. Dismantling a Summar can be done, but apparently they were never made with that kind of servicing in mind so it's difficult. Docter says: keep it warm and exercise it regularly, it might 'ungum' the grease a bit!

Maybe other members have more usable advice, sorry.

 

[johannielscom]

DANGER, WILL ROBINSON !!!

Just noticed: DO NOT COLLAPSE ON THE M5 !!!

You'll wreck the meter cell on it's pivoting arm for sure!

That bit of tape is a good one to make sure you don't make the mistake. And, never hand it over to anybody without first explaining the collapsing risk!

 

[john neal]

You can free up the aperture but it takes great care - remove the front element (I think there is a screw in the ring somewhere), close the aperture and clean it VERY carefully with a cotton bud & some Ronsonol. Work the aperture while the blades are still wet, clean with another bud and repeat 15 or 20 times.

Don't flood it with liquid, just moisten it so you can remove the crud.

I have done this 3 times now with good success. Of course, you could send it to Sherry for a real workover.

Tape over the barrel is a good idea to stop you collapsing it - have never had any joy in improving worn-out felt in the mount. It's actually horse-hair felt. Getting it moist with some oil might work though, it should certainly help it swell up some.

 

[David Hughes]

If you don't want to do the Dymo tape on the barrel trick, then use an elastic band wound a few times round the barrel at the back. Dirt cheap and easily removed but it won't do tape sales much good...

Regards, David

 

[Gazzah]

Thanks all

Thanks all

BuzzardKid - I had noticed that the tabs run under the ridges - but it seems to be so worn that they dont "lock" in place.
i was aware that I couldnt colapse the lens on the M5 - thats why I want to lock it in place !

John - I tried removing the fron element - well I undid all the screws in the front section of the barrel - but no joy, the fornt element would not budge!

david - I did put tape on - but it still allowed the barrel to rotate, so I put a small bead of rubber glue around the base, left it overnight and it seems to have worked, it doesnt rotate and doesnt colapse. It should be easy to remove if I ever want to.

So thanks all for the advice - I will try it out this w/e and see how it performs. It was real cheap so Im not out by much if it turns out to be a dog.

Gary H

 

[hans voralberg]

Gazzah, the front element can be very hard, try suck it up with a suction cup or use rubber pads

 

[greyelm]

If you want a less unsightly method to stop the summar collapsing try this, I used the tube from "Loctite Repair Express Power Putty". I cut the tube to the length of the lens barrel and made a split down the side. This can be slipped over the lens barrel to prevent accidental collapsing.

I have also used this on Elmars, Sumitars & Industar-22s and they are almost invisible in use.

I replaced the felt in my Summar with a piece of 'fluffy side' velcro. It has had some effect but I don't expect it to last.

 

[john neal]

Gary,

The front element is peened into the metal ring - there could be a screw in the front face that stops it from rotating. I must check in my books for the answer.

 

[Gazzah]

John - thanks - I cant find any screw in the front face, but will have another look.

Gary H