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Aaton A Minima - Film Cores


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#1 Robert Lewis

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Posted 07 November 2015 - 02:29 PM

I have been thinking about buying an Aaton A Minima as a camera light enough to take abroad on holidays, etc, instead of the much heavier Aaton LTR54 I have. That said I am concerned about the discontinuation by Kodak of the special spools with flanges and cores which I understand were developed jointly with Aaton and which are said to be patented by Kodak. Kodak advise that their spools should only be used a few times, and so there seems to be an risk of obsolescence which, if there is no way around it, could mean that the A Minima will shortly become useless.

 

I know that film stock can be reversed so it is presently possible to buy stock, reverse the winding to "A" (emulsion outward) as long as one has spools and cores, but if spools and/or cores really do cease to be available, even that would not be possible. Or would it?

 

Having looked very closely at photographs, some good and some not so good, it does seem to me that it might be that the standard 16mm two inch cores might be useable but without the flanges which the Kodak spools and flanges used to come with, if the flanges were originally used in order to provide for "daylight" loading and the cores will fit the camera drives. It seems to me, but only with the benefit of photographs, that the first type of core used by Kodak is almost identical to the present day standard 2 inch core modified to accept the flanges.

 

I am wondering if any owner of an A Minima has any experience in using standard cores in their camera - whether firstly the core itself will fit, and secondly whether there is any problem as a result of there being no flanges. This, of course, the arrangement used in other 16mm Aaton cameras and the Arriflex SR family.

 

Any help on this point would be most helpful and appreciated.

 

 

 

 


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#2 Gregg MacPherson

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Posted 07 November 2015 - 03:41 PM

Can a standard 200' metal spool fit the A Minima mag?  It's just as a 100' spool but bigger. They are sturdy. 


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#3 Dirk DeJonghe

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Posted 07 November 2015 - 03:52 PM

No, 200ft metal spools won't fit. The plastic spools are driven by the edge, not by the centre. Most labs have a reasonable supply of empty spools for their customers.
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#4 Robert Lewis

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Posted 07 November 2015 - 04:25 PM

I was aware that the traditioonal metal spools couldn't possibly work, whether they are 100ft or 200ft. They have the square centre holes to engage in the square drive. However, I had no idea that the Minima spools were not driven from the centre, but from the edge. So, thank you Dirk for that information. It would appear that there is no alternative to trying to obtain a supply of the original spools and cores. I had looked at every piece of information I could find on the web, and saw nothing to suggest that they were driven from the edge. Since I had not managed to inspect a camera, it never occurred to me that that was the case. It does seem most unfortunate that the future of these cameras is left to the possibility that labs might have some they would make available which may, or may not, be the case for any length of time, with some many labs having closed down. In all honesty, I rather feel that this is not a satisfactory state of affairs, especially since Kodak appear to have patented the spool and and may not allow others to produce it.


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#5 Kalle Folke

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Posted 07 November 2015 - 04:34 PM

Hi!

When I bought my a-minima I made sure I got some empty spools and cans included in the sale. I turned out I never had a need of them since my lab (Stopp in Stockholm, Sweden) could supply them. They re-spooled the film for me and got the spools back when they developed the film. They're made out of plastic and to me it seems they will last a long time as long as you don't accidentally break them by force.

I'd say 10-20 spools would last you many years and I would not make the spools a reason not to get this camera if you want it. I sold mine since I got a Arri 416 also, but I will sure miss it and probably will try to get one again in the future. The small form factor is worth it, re-spooling and all!

 

I don't know about 3D printing, but from what I've understood about it maybe making spools could be possible?


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#6 Kenny N Suleimanagich

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Posted 07 November 2015 - 05:15 PM

If you do the process in the dark, then you don't have to worry about the flange tolerances leaking in light during a daylight load. That's the main issue (and them breaking).
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#7 Robert Lewis

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Posted 07 November 2015 - 05:17 PM

Dirk ... I understand the drive system now. It is clear that the centres on which the spools and cores fit are not driven. They are free running. The drive is provided by the edges of the spools themselves engaging with the feed and takeup spockets when the magazine is inserted fully into the camera. So it is for this reason that the camera cannot work if there are no flanges. No spools no drive! It is as simple as that. There is a very simple description in the operator manual, in the magazine section, but it is so easy to miss the significance of it. Many thanks.

 

Kalle ... Thank you for your words of comfort.


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#8 Gregg MacPherson

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Posted 07 November 2015 - 05:46 PM

If the Kodak spools run out,  perhaps a replacement can be designed that's not too costly. 

 

To be clear,  the spool is driven at its rim?  It's a friction drive?  Does anyone have a pic or drawing of the place where the drive engages?

 

Explicit pics or drawings of the spool on its own?  (I have an A Minima user manual already,  though I never looked at it before)


Edited by Gregg MacPherson, 07 November 2015 - 05:48 PM.

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#9 Dirk DeJonghe

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Posted 08 November 2015 - 12:42 PM

The roller driving the edge of the spool also pushes the flanges apart to let the film pass easily. When you remove the exposed spool from the camera you should let it fall by gravity, not pull it by the flexible flanges that assure a certain protection from edge-fogging.When self-spooling 400ft loads to the Minima spools, you twist the film slightly to fit between the higher rim of the flanges that stop light from fogging the edges. Regardless, it is advised to load the Minima mags in as subdued light as practical, complete darkness or a changing bag is a good idea.
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#10 Pavan Deep

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Posted 08 November 2015 - 03:07 PM

What roller? Where is it? I have been looking at how the camera turns the take up spool and I can't see how it does, I can't see any connection where the camera turns the take up spool. I have recently handled an Aaton Minima and it seems that the feed spool locks onto the take up spool, as the film is pulled out by the camera claw the feed spool rotates and because it's locked to the take up spool it turns it in the same direction. Is this why the Aaton Minima requires film to be wound emulsion out? 

 

Pav


Edited by Pavan Deep, 08 November 2015 - 03:10 PM.

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#11 Dirk DeJonghe

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Posted 08 November 2015 - 04:10 PM

if you take the magazine off, you will see two rollers with a rubber coating (o-ring). These are the ones driving the takeup spool. When you push the magazine forward to the ready position, these rollers will contact the plastic film spool and open it slightly since the shape of the spool edges is angled.


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#12 Pavan Deep

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Posted 08 November 2015 - 04:42 PM

Okay I will look. How do these rollers turn? Is the feed spool turning them?

 

Thanks

 

Pav


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#13 Robert Lewis

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Posted 08 November 2015 - 05:52 PM

I was puzzled too by the fact that I could not see in photographs how the feed and take up spools were driven. There appeared to be no drive system as one finds in, say, Arriflex cameras or larger Aaton cameras. Then, after an earlier contribution by Dirk, it became clear.

 

In the front part of the camera, there are the feed and take-up sprocket rollers (the rollers which include the sprockets). On each of the four rims of those rollers, there is, I believe, a" tyre". When the loaded magazine is pushed forward to the front part of the camera, as part of the loading procedure, the spool flanges "mate" with the tyres referred to above and slightly force open the flanges at the points at which the film passes from and to the magazine and the friction so created drives the the spools. Because the speed of the sprocket rollers is always synchronised with the speed at which the film is required to be delivered and collected from the rollers, the whole system works perfectly. Very clever and very simple I think.


Edited by Robert Lewis, 08 November 2015 - 05:54 PM.

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#14 Pavan Deep

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Posted 09 November 2015 - 12:04 PM

That is clever and simple, I can now see the potential strain on the spools. I just had a closer look at the Minima and you’re right I can now see how take up spool is driven, it is the ‘tires’ from the sprocket drive that turn the take up spool. I am still puzzled as to why the film is wound emulsion out.

 

Pav


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#15 Robert Lewis

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Posted 09 November 2015 - 02:12 PM

Hi Pavan.

 

I think that emulsion out is is necessary because Aaton could not find a way of reversing the film to get it to the gate with the emulsion facing the lens. For example, whilst the Arriflex and big brother Aaton cameras use B wind film (emulsion in) as the film passes through the magazine to the gate in the main part of the camera, the face is reversed as it has to be in order to have the emulsion side facing the lens. One doesn't notice this reversing of the film on its way from the feed side of the magazine and from the gate to the take-up side of the magazine, but it is there. If one looks at the path the film takes in the Aaton A Minima, these reverses simply cannot be achieved, and so because the emulsion side the stock has to go through the gate facing the lens, and there is no way of reversing it, it has to start and end its journey with the emulsion facing out.

 

By the way, do you have an Aaton A Minima?

 

Regards,

 

Robert.


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#16 Pavan Deep

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Posted 09 November 2015 - 03:19 PM

I have done workshops where I used an Aaton Minima with the Kodak spools; I’ve got some Minima spools, but haven’t got the camera, though I might buy one, there’s one nearby that I might buy and I’ve been to see it, it looks a bit over used but functions well, I'd be happier to get hold of a service manual I asked Aaton but haven’t heard back. I’m worried about the emulsion out thing as loading film onto the spools isn’t that straight forward because the spool flanges need to be slightly forced open to when spooling the film. I might be wrong, but I believe that film which is ‘emulsion in’ needs to settle and not all ‘emulsion in’ stocks work well when wound [at home for the Minima] as ‘emulsion out’, I believe most film is 'emulsion in'.

 

 

 

Pav


Edited by Pavan Deep, 09 November 2015 - 03:23 PM.

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#17 Gregg MacPherson

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Posted 09 November 2015 - 04:41 PM

 

.... loading film onto the spools isn’t that straight forward because the spool flanges need to be slightly forced open to when spooling the film. I might be wrong, but I believe that film which is ‘emulsion in’ needs to settle and not all ‘emulsion in’ stocks work well when wound [at home for the Minima] as ‘emulsion out’, I believe most film is 'emulsion in'.

 

 

I thought Dirk's tip on self spooling was the right way,  just twist the film a little as it goes into the spool.  If the rewinds are fairly close together this isn't too hard to do.  Otherwise you may have to improvise some friction on the split spool on the feed rewind.


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#18 Robert Lewis

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Posted 09 November 2015 - 05:45 PM

I think guiding the film  between thumb and forefinger and "twisting the feed" whilst self spooling is easy enough, but I think one would have to be careful about creating static electricity. I am not sure how one might avoid it, but I do believe that it could cause problems if it couldn't be avoided.


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#19 Gregg MacPherson

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Posted 09 November 2015 - 08:18 PM

Plenty of people have spooled their own film OK. But yes there may be factors, unobserved, that could give failure. Humidity meters are cheap now. Might help. You could try looking for static with expired film.

(edit) Give you eyes plenty of time to get used to the dark.

Edited by Gregg MacPherson, 09 November 2015 - 08:19 PM.

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#20 Dirk DeJonghe

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Posted 09 November 2015 - 10:56 PM

Static is never a problem with colour film because of the remjet backing which contains carbon and is conductive.The main concern is not overfilling the spools so the film doesn't jump the ridge on the inside of the flange.
Kodak doesn't tape the tail to the spool and there is no slot. I use a very low tack paper tape to start the tail on the core. Using a stronger tape may cause jams when the camera runs out.
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