Aaton A-Minima Daylight Reel Designs

[Kamran Pakseresht]

Hi there,

I finally had some time today to take a look at the A-Minima spools I bought off Ebay a while back and see if I could recreate them, as it seemed that folks were having a hard time finding them. @Dirk DeJonghe mentioned in my original split reel post that hey had become difficult to source.

I might need a little help from the community with some questions about the camera, and also in testing these, because I do not have this camera myself. I would be happy to send them to someone if they were able to test.

I first started with the core:


the top is the original and the bottom is the 3d printed version:



This works well - I tested it with the original flexible flanges and it functions exactly the same as the existing core.

Onto the flexible flanges:


These are much trickier because they have a specifically designed ramped slot to slide onto the core on the underside, i'll explain:


The little slanted side allows the core to easily slide in one way - but to be a bit more stiff coming out the other way - this works well! But the issue is actually in the orientation, it is facing downwards when printing:


The reason this is an issue is that the underside of any free-standing surface in a 3d print is typically much lower quality because of the need for support, so I have decided to make these parts separate so the locking mechanism can be printed in an orientation that will ensure a good resolution. This part is then super-glued into notches on the flange base.

It is a bit tricky because when 3d printing you have to design things with the strengths of 3d printers in mind - so I may actually end up providing two different sets of models - 1 that is optimized for 3d printing and 1 that could be used to make a mold for mass production (basically an exact copy of the existing spools).

So these are not finished yet - I was hoping some people could chime in on the properties of these spools that make them unique? I was reading in the A-minima manual here:
"standard metallic 200 spools and 400' reels cannot be used with the A-Minima" - why exactly is it that metal 200' spools can't be used? My assumption is that the flexibility of these reels is an important aspect of their function?

I'd love to hear from someone who has actually used the camera so that I can plan accordingly with the materials and design considerations. And as always I'll be making these designs available for anyone who might want to use them - assuming they end up working!

Thanks!

[Mark Dunn]

From what I can see, the spool flanges have to be flexible as they are levered apart by the sprockets when the mag is attached. This is why the camera is so small. So a metal spool simply won't fit.

Edited January 11 by Mark Dunn

[Robin Phillips]

I think its important to note that there is no way to refine an after market product without having a camera body to test with. also the tools to re-spool the film the way the a minima needs. if it was a simple matter of 3d printing parts with the same dimensions this problem would have been solved already. I think you'll find that the materials will be critical to any successful reproduction, along with the insights of a technician who troubleshooted a lot of these cameras. 

to be clear Im not saying dont try. but I cant see any way of being successful without a camera, mags, and a film rewinder to facilitate any tests. (you could alternatively get fotokem to respool the film for the camera, but that adds up fast)

[Kamran Pakseresht]

Yea I am intending to send some prototypes off to some owners for testing - as well as making the designs available for others to print themselves and iterate on if they'd like. I'm not in a rush, eventually we'll end up with a functioning A-Minima 200' daylight spool that can be affordably printed, will work well, and will help keep these cameras chugging.

It's not that complex of a problem, it's just a niche problem, which is why it hasn't been solved yet.

Now seems like a good time since these spools are getting harder to find.

[Martin Parsekian]

YES! Ive been waiting for someone to do this! To answer one of your questions, the spools were a little flexible to allow the film stock to pull through the take up and feed sides smoothly. The sprocket drives have rubber gaskets on them that engage with the spools- they drive the spools themselves while forcing them open a little so the stock can run through the camera smoothly. 

I have found that the resistance has to be pretty dialed in for the camera to run well. Sometimes with older spools the camera seems to feed/take-up too quickly and jam. Someone like Tyler who knows these cameras better may have more details. I have been able to rectify this by taking the magazine into a dark bag and checking the tension on the take up side. Not fun on set 😅

Attached is a pic of my Minima with the magazine open so you can see the drive mech/ how the rubber ring engages with the flange of the spool to drive it. 

One last thought is Ive always wondered if a different material on the spools would make the camera run quieter? Most of the noise from mine seems to be the film edges scraping against the spools. It seems to vary between spools in my case. 

Id love some new 3D printed spools if they run more reliably and would be happy to test for you! 

[Martin Parsekian]

Onee last thought I wanted to share is that personally, Ive yet to encounter a situation where I needed to split apart the spools. Not sure if others have different experiences. It might help simplify your design if it's just one piece? 

[Tyler Purcell]

We have a really nice updated spool design. We've been struggling with printing it properly, but I think we may have cracked that nut recently. I'm gonna sick my partner on it and see if we can get it done in the next week or two. Plz keep an eye out on our instagram @tye1138 and the Aaton Facebook group, I will be updating people on those two platforms.