Minolta Minoltina-S Film Rewind

[tzeH]

Hello,

I bought a Minoltina-S in broken state thinking that I could get it back in working order... So far I have fixed several things, like hardened grease in the film transport, that I thought were the problem but now I am stuck.

What's puzzling me is that I have no idea, how the film rewind should work! Yes I need to push the rewind button at the bottom. This "frees" the first roller that engages with the holes in the film. That button works and it does what it should.

But the "main spool" that rolls up the film while you shoot is never released. So I can't pull the film backwards. I can supply more images later, if that helps. I must be missing something fairly basic here...

Do you have an idea, how that should work?

 

[AlexBG]

Do you mean the spool that the film winds round? That won't release?
Mine has film in currently so I can't open the back at the moment.

 

[Ranchu]

You're a lot father in there than I've been. The take up spool that has the film catch slot in it is like a clutch or friction fit on an inner shaft. It can't be geared with the sprocketed spool because the diameter of the film on the takeup spool changes as it's taken up over the length of the roll. You should be able to turn the takeup spool in both directions just with your thumb on it, with a little resistance, like most other manual wind cameras. If not, dried grease may have glued it to the inner shaft, or some other problem..

 

[tzeH]

Do you mean the spool that the film winds round? That won't release?
Mine has film in currently so I can't open the back at the moment.

Yes, exactly. It turns easily in one direction - when I do that I hear a clicking sound as this is the same direction as winding the film.
The other direction is blocked entirely.

You're a lot father in there than I've been. The take up spool that has the film catch slot in it is like a clutch or friction fit on an inner shaft. It can't be geared with the sprocketed spool because the diameter of the film on the takeup spool changes as it's taken up over the length of the roll. You should be able to turn the takeup spool in both directions just with your thumb on it, with a little resistance, like most other manual wind cameras. If not, dried grease may have glued it to the inner shaft, or some other problem..

Hm! The inner shaft is free, I can easily move it a millimeter or so with a screwdriver. But that gives me an idea:

At the top is a gear that engages with the black spool directly. That gear consists of two parts, a tube-part and a gear-part. I had already suspected that these two should be a friction fit and not one unseparable part. They might be glued together by more grease but honestly, they seemed so well connected, that I doubted I should get them apart - so far. Might give them a bath in lighter fluid.
Will send a picture of it in an hour or so.

The information that the spool has a friction fit in most other rangefinders, might be the crucial part of information that I missed Thanks, I'll keep you posted!

 

[Ranchu]

I checked my Minoltina S before I posted, the takeup spool moves pretty easily both directions. Best Luck! Edit:Mine has no clicking sound when the takeup spool is turned either direction, independently of the (stationary) sprocketed spool. When both are turned together, there's the clicking. It's the sprocketed spool that makes the clicking sound..Mine is the Minoltina AL-s, which is the same camera as far as I know.

 

[tzeH]

Thanks! So here is the part that I suspect... not sure if that is the right one but I guess we'll see if lighter fluid will make a difference...

 

[Ranchu]

Good luck, maybe acetone would work well?

 

[AlexBG]

Yes, exactly. It turns easily in one direction - when I do that I hear a clicking sound as this is the same direction as winding the film.
The other direction is blocked entirely.

That sounds to me like the rewind button isn't working then?

Have you tried loading a film, keep the back open, take a few shots and then try to rewind?

 

[rick oleson]

I think you're on it, that looks like it's probably a friction clutch. If the lighter fluid doesn't free it up, I would try substituting Xylene. I've had great results with that for freeing up hopelessly hardened stuff (it also removes paint and dissolves plastic, so you can't use it in all the places you can use lighter fluid. I save it for this kind of problem.)

 

[tzeH]

That sounds to me like the rewind button isn't working then?

Have you tried loading a film, keep the back open, take a few shots and then try to rewind?

Hi, Alex

yes I tried that - the spocket spool is moving when I press the film rewind but the takeup spool isn't.

I think you're on it, that looks like it's probably a friction clutch. If the lighter fluid doesn't free it up, I would try substituting Xylene. I've had great results with that for freeing up hopelessly hardened stuff (it also removes paint and dissolves plastic, so you can't use it in all the places you can use lighter fluid. I save it for this kind of problem.)

Ha!

Success so far: None. Still stuck and I did apply all the force that I could (given that there are very little points that I can apply it to...).

Next contender is Acetone. After that I'll try Xylene, which is a little harder to get my hands on.

Thanks so far!

 

[rick oleson]

I haven't had much luck with Acetone with this sort of thing.

 

[Ranchu]

Would 15 minutes in a warm oven help, do you think, Rick?

 

[tzeH]

Ha! I did it! Well, the Acetone did. No idea why it worked but it did. After 6 hours, I was able to move it a little bit. After a few more, It fell apart right away. I doubted that would ever happen. Wow!

Thanks everybody for their help! Btw. I did manufacture a replacement part with a 3D stainless steel printing service. If you are interested in how that goes, I'll keep you posted

Ah, when I reassemble this, should I keep it dry or should I apply some silicone grease or watch oil?
I am not sure that the original grease was meant to be there - maybe it just migrated inside that friction clutch from the outside.

 

[Shafovaloff1]

My suspicion is that there is a stuck part in bottom of camera, or even shaft inside its guide to bottom of camera. However, my parts camera takeup spool moves in reverse but has more resistance than my refurbished camera.*** I just checked my refurbished camera and the takup spool maintains resistance but moves in reverse with finger pressure whether or not the rewind button is pushed..but much less easily than in the wind direction [no resistance]leading me to believe that your spool is stuck and not that there is actually a broken part.***

 

[Shafovaloff1]

Let me know if I can help with parts. I am not the greatest at disassembly so you may have to "you pull it"....;-). No touch a the two way mirror in these cameras...nothing new. Often they have problems with the electrical contacts for the the meter shutter/aperture parts..delicate...careful....aperture and shutter take time to clean but can be in situ. I is novice.

 

[rick oleson]

Excellent, congratulations! Whether to lubricate, and with what, may require some experimenting on your part. It probably had some sort of lubricant originally, and that probably hardened with age and made it freeze up. If it's too well lubricated, though, it will slip too easily and fail to wind up the film as you advance.

Part of your decision may be related to how and how much you plan to use the camera: for heavy use it would want some lubrication to reduce wear; but if it's not going to be used much, wear may be less of an issue than lubricant stiffening while on the shelf. In any case, you want to have enough friction to reliably advance the film, so I would try a bit of silicone or lithium grease first and if it's too slippery clean that out and try something thicker (or try it dry if it's going to be mostly for display and just occasional use)

 

[rick oleson]

PS: I've done the 3D-printed stainless steel thing one time and it worked out great. A bit rough on surface finish, which might affect a gear or a clutch, but it was not a problem for the part that I had made. It was surprisingly inexpensive, much less than the cost for materials to machine the equivalent part.

 

[Ranchu]

Thanks for the thread, this was good to learn.

 

[Steve M.]

If I need to lube anything, I always go w/ a tiny touch of synthetic bike chain oil on these type of things, or just put them up dry. Nothing bad can happen if you put it together w/ no oil, which is always a point in it's favor.

 

[tzeH]

I now have a minoltina p for spares! Any idea how to get the top off?!