Mamiya 6 IVb Frame Spacing

apf102 · Sep 22, 2023

Hi. I am a relatively new owner of a Mamiya 6 IVb (1955 folder).

The camera generally works great but I have noticed some issues with frame spacing. Some frames are much further apart than others which is a pain when scanning. Occasionally one will overlap. I’ve also noticed when home developing that the last frame is very close to the end of the film roll, so I have started winding on a little less film before advancing to frame 1.

Having read some threads on here it seems the mechanism to advance just has notches which stop the advance, so I am not sure how these would go wrong.

So the questions:

1) Is there a problem here with the advance or is the film slipping somewhere? Would explain overlaps but not the wide spacing.

2) is this actually just a product of the focus mechanism? The Mamiya 6 moves the actual film not the lens to focus. If I shoot 1 frame close and then another at infinity, would this move the film enough to create the weird spacing?

Any help much appreciated before I start dismantling.

Cheers

Alex

Dan Daniel · Sep 22, 2023

Most likely the frame spacing mechanism needs a cleaning. I don't remember the specifics right now but there will be a pawl and a lever or two. These metal parts get oxidation and such, dirt, old grease, etc. and don't move as smoothly as they should. Open up the top and clean things, remove levers if you can and polish their friction areas, clean the ratchet and pawls and deburr if needed, and all will be good.

The ratchet mechanism will do exactly what you describe when dirty- not fall into place at the right time, late on one frame allowing for wide frame spacing, then 'make up for it' on another. The focus mechanism could add to the frame spacing, but I've never heard of that before.

Sirius Glass · Sep 22, 2023

apf102 said:
Hi. I am a relatively new owner of a Mamiya 6 IVb (1955 folder).

The camera generally works great but I have noticed some issues with frame spacing. Some frames are much further apart than others which is a pain when scanning. Occasionally one will overlap. I’ve also noticed when home developing that the last frame is very close to the end of the film roll, so I have started winding on a little less film before advancing to frame 1.

Having read some threads on here it seems the mechanism to advance just has notches which stop the advance, so I am not sure how these would go wrong.

So the questions:

1) Is there a problem here with the advance or is the film slipping somewhere? Would explain overlaps but not the wide spacing.

2) is this actually just a product of the focus mechanism? The Mamiya 6 moves the actual film not the lens to focus. If I shoot 1 frame close and then another at infinity, would this move the film enough to create the weird spacing?

Any help much appreciated before I start dismantling.

Cheers

Alex

Have a repair man do a CLA [Clean, Lubricate & Adjust] to correct the spacing problem and other problems that you do not know about. You will be glad that you did.

Welcome to ~~APUG~~ Photrio!!

awty · Sep 22, 2023

As Dan said it will need cleaning at the very least, it may also have worn or damaged parts.
I have a Mamiyaflex that does similar, one of the little cogs is damaged and the winder is bent ( bought it that way) so I just use the the window on the back to advance the film. I'm not sure if yours is able to do that.

nosmok · Sep 22, 2023

Probably all of this cleaning and adjusting might need to be done, but it may not hurt to try the old "wrap a layer or 2 of masking tape around the takeup spool" trick and see if that helps first. Some people whose opinion I respect have said that older 120 spools were thicker than the new ones, and that can play havoc with auto-stop advances

awty · Sep 23, 2023

nosmok said:
Probably all of this cleaning and adjusting might need to be done, but it may not hurt to try the old "wrap a layer or 2 of masking tape around the takeup spool" trick and see if that helps first. Some people whose opinion I respect have said that older 120 spools were thicker than the new ones, and that can play havoc with auto-stop advances

If it were just that then the spacings would be consistently getting smaller and overlapping at the end and you should have more unexposed film at the end not less.
The mechanism on my Mamiyaflex is this, as the OPs camera is similar vintage it should be similar. There is nothing to adjust, just clean and lube.

Mamiya 6 IVb Frame Spacing

apf102

Dan Daniel

Sirius Glass

awty

nosmok

awty

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