Loose 40mm Rokkor - any help?

[mbrxjepp]

Hi all, recently bought a Minolta cle with 40mm Rokkor in great condition. The only drawback seems to be that there is a little play in the lens barrel. I am about to order a lens wrench from microtools in Germany and wouldn't mind having a go at fixing this myself with a bit of help.

Is this something I can remedy without too much hassle or should I be looking for a repair shop nearby?

Tried doing a search in the archives but nothing immediately useful showed up.

Any advice or references to other sites/threads would be greatly appreciated!

Thanks,

Ewan (Manchester, UK)

 

[ddutchison]

Hi,

I'm thinking you'll get a better response if you post your question on RFF's own "Repair Notes" forum (which is located here ). Some pretty savvy people hang out there.

Best of luck

 

[mbrxjepp]

Thanks for shifting the question - I realised i'd chosen the wrong place just after I posted and didn't know I could move it.

It's the 'base' of the lens that's loose, i.e. the part that includes the mount - perhaps i'll just have a go at taking it apart and see what I can find out...

Cheers,

Ewan

 

[ddutchison]

I guess no one here plays with Rokkors/Summicon-C's!

I would suggest that if you are the least bit unsure about what you're doing,that you get an estimate from your local repair person. I might be very inexpensive (and those 40's are some nice lenses).

Here are 2 other camera repair forums I know of...

The Yahoo Camera-fix group
The Classic Camera Repair Forum

Maybe someone there will be able to help.

 

[leafy]

I recently acquired a Summicron-C 40/2. It once exhibited a similar sympton. I can turn the front part of the lens all way round and round. In the end I found that the retension ring for the rear element was loose. Tightening it (and made sure to line up the white dot on the front and the triangle on the DOF indicator) fixed all my problems. You can try to tighten things up first, it might help.

 

[mbrxjepp]

Thanks for the help.

Leafy - can you explain how to get to the retention ring for the rear element, and how it is tightened? It sounds like you're describing something pretty easy to do but i'm not very knowledgeable about the anatomy of lenses! I'm sure this fix shouldn't require a trip to the repair shop, and I like to know how things work.

Cheers

 

[leafy]

I am using a dirty fix since I don't have the proper tools with me. Flip and lens and look at it from the rear. The rear element has a ring around it with 2 very tiny dented notches. This ring is threaded and holds the whole thing in place (what a surprise to me!)

The tool is supposed to be inserted into the notches and turn clockwise to fasten it. I used my fingers....it seems to be tight enough for use now, until I have access to the proper tool.

 

[mbrxjepp]

Ah - I know exactly the part you mean. I'm about to buy a lens wrench to do stuff like this properly but will see if I can do what you have done when I get home this evening.

Thanks very much, will post a reply to let you know how I get on.

Ewan

 

[Kim Coxon]

Hi,
Just a thought. I use a pair of needle nosed pliers for such jobs. Easier and a lot cheaper than lens spanners unless you get the really expensive ones with a whole set of tips. You just need a little more care to make sure you don't slip. Pic attached.

Kim

 

[leafy]

I'd really advise against this particular tool. It's too easy to slip because the ring is small. It is also not certain if the plier is too hard for the threaded ring, and it might just damage the notches for good. Human fingernails are soft enough, and they grow back even if damaged in the process 🙂

 

[mbrxjepp]

Thanks Kim, that tool certainly would be a cheaper option but i'm not sure i'd trust it in my hands near an as yet unspoilt lens!

Got home this evening and checked the retention ring at the rear of the lens but it seemed pretty tight to me. I used some bamboo kebab skewers to get a little puschase in the notches (not enough to unscrew it but enough to see if it was loose). They have the advantage of being relatively soft and less likely to cause damage.

So, the mystery continues. Any other suggestions from you good people?

 

[mbrxjepp]

Update - took the lens to my local independent camera shop where I am getting to know the owner, and he thought the lens was fine. He suggested it was the helical focusing threads that gave rise to the play, and this was normal for many lenses. He said I could spend money having the threads packed with grease but this would probably only work its way out again leaving the lens in the same state it's in now.

So, if this is normal then I'm not really worried about it.

Thanks for everyone's input - it's a pleasure to have access to so many people's considered views.

Ewan

 

[45-Otto]

I had a similar experience with my 40MM Rokkor and determined that it was indeed tolerance or "slop" in the focussing helical threads. I found it a rather simple task to dismantle the lens barrel and relubricate the helical with "Nye Lubricants" extra light damping grease available from Micro-Tools. After helical cleaning, relubrication and reassembly almost all play was removed from the lens and the focus movement was dampened properly again. Hope this helps.

 

[mbrxjepp]

That's great advice - now you mention it the focus movement is a little too free compared to other lenses i've used. Any chance you can outline the dissassembly process? I'm ordering a few things from micro-tools and may as well buy some grease and have a go!