Pentacon 6 to Mamiya 645 adaptor problem

<p>I have been using an old Zeiss Jena Flektogon on my Mamiya 645, using an adaptor which I bought some years ago. I have a problem with it, however: I cannot separate it from the lens again! Is there some cunning trick to this?</p>

<p>My adapter has a rotating cuff that allows me to attach/unattach it to/from the lens. Sometimes it gets a bit tight. Good luck. JR</p>

<p>If it is not oxydised it may help to put it in a fridge for some hours and try it if it is cold and the material a little bit smaller. It's only an idea, who knows.</p>

<p>Many of these adapters are milled from Aluminum which oxydises over time. Also there is the issue that this oxydization occures faster when the AL is in contact with other metal.<br>

If the mount adapter has been left on too long it might be impoosible to remove without partial disassembly of the lens.</p>

<p>A strap wrench, which can be found at any GOOD hardware store can be used to turn the stuck P-6 breech lock mounting ring without doing any damage.This is a good tool for anyone who uses P-6 mount lenses or bodies. After the adaptor is unstuck you can "lubricate" it by rubbing a lead pencil over the exposed parts of the mount.</p>

<p>Thanks everyone. So it sounds as if it is just a matter of force. It feels so rigid I was afraid there was some catch or lock that I didn't know how to disengage, but if I'm sure there isn't I can try using more strength, or a wrench as suggested.</p>

<p>No, I can't shift it, no matter what I do. I can't use any more force or something will break. It's not oxidised onto the lens, there's some free play (there always was). It feels as though there is some kind of lock, but there is no button to press to release it, as there is on the camera body when you want to release a Mamiya bayonet and take a lens off. There is a tiny hole in the side of the adaptor at one point with a small silver screw visible in it - I wonder if this would somehow help me to dismantle it.<br>

<br /> I'll take some pictures and post them, I guess, in the hope that someone recognises the make of adaptor and knows the trick....</p>

<p>take the lens in one hand while the lens is facing up and you are holding it by the adapter mount you want to take off.<br />with the other hand start to turn the lock-ring counter-clock-wise. this way you are not actually touching the lens itself but the adapter and the ring.<br />at some point of the ring movement (about 50 degrees) the lens will become free to lift it up and away. it is intended to happen when ring cannot go further.<br />this ring is actually a huge nut sitting on the adapter. there are screw threads between them. maybe they are busted or dented or whatever.<br />that tiny screw you mentioned will not help you at all.</p>

This is a new comment to an old post. I bought one of these inexpensive Chinese adapters recently, It worked fine a few times, and then within a week or two after purchase, it stuck. And I do mean STUCK!!! A strap wrench won't budge anything. Removing the screw from the outer ring doesn't do anything. Looks like I'm going to have to cut it off with a Dremel tool. The suggestion about fitting the adapter onto a cheap doubler or some such is a great suggestion.

 

Be careful with these cheap adapters. From what I have read, sticking is a too common problem.

Edited September 28, 2022 by robert_peters|2

This is a new comment to an old post. I bought one of these inexpensive Chinese adapters recently, It worked fine a few times, and then within a week or two after purchase, it stuck. And I do mean STUCK!!! A strap wrench won't budge anything. Removing the screw from the outer ring doesn't do anything. Looks like I'm going to have to cut it off with a Dremel tool. The suggestion about fitting the adapter onto a cheap doubler or some such is a great suggestion.

 

Be careful with these cheap adapters. From what I have read, sticking is a too common problem.

Badly machined threads will do that!

It's a similar issue to having a stuck lens filter.

 

The screw in the Pentacon mount is simply a rotation stop to prevent the bayonet ring from completely unscrewing when undone. It serves no purpose when a lens is fitted.

 

Have you tried playing a hair-dryer onto the bayonet ring? Maybe after having the whole assembly sitting in the fridge for a few hours.

 

A bit of sheet rubber, or thick rubber gloves, gives much better purchase and avoids bruising or skinning your hands or fingers.

 

As a last resort, you could try clubbing the outer bayonet ring with a length of wood - in the direction of 'undo' of course; that's anti-clockwise looking from the front. By 'clubbing' I mean obliquely heavily tapping the ring with the wood, while rotating the point of impact (generally the wood comes off a lot worse than the metal). This has worked for me on quite a few stuck threaded rings, including filters.

 

And averse as I am to the stuff, penetrating oil sometimes helps - NOT WD-40 - that's not a penetrating oil.

 

And when you do get the thing undone, I suggest you remove the screw, enabling the bayonet ring to be completely unscrewed. This allows you to clean the threads with a wire brush or similar, and to lubricate them with candle wax (doesn't creep or run like grease) before re-assembly.

 

That's about all the tips I've got. Good luck!