Projectorless solution

[Kurt Euler]

Hi. I’m new to this group. I’m wondering in anyone has replaced the projector with an alternative film advancement technique. I’m thinking of for example a stepper motor with custom gears and cogs to position and andvance the film frame by frame.

In short is there a solution for those who don’t have a projector available for video capture.

Thanks!

Kurt

[Nathan Miller]

I debated this during the setup of my projector based system because I had to 3D print several pieces for the camera mount and drivetrain. I thought that for just a little more trouble I could design and print a complete frame advance mechanism. In the end I decided against it though because there is quite a bit of engineering that goes into advancing the film, keeping it taught and in plane, and keeping it perfectly aligned. It really is worth it in my opinion to hunt down a donor projector on eBay and start there. Bell and Howells can be found for $50 or less.

[Clayton Weaver]

I did a fully 3d printed drivetrain version (no projector) because I had the time (retired) and wanted to play with a then new 3d printer.  Result could be improved mechanically / programatically / electronically and was slower than the efforts using projectors described here, but I was pleased with quality and successfully captured my small-ish collection of 1970's super8mm film.  See 1st post in this group a couple of years ago or https://github.com/weaverch/super8scan.  Final quality was better than clip I posted to Youtube.

[Pat]

There are some valid cases for which a projectorless solution makes absolutely sense. Some are:

 - complete access to the film between the spools

 - as little bends in the transport as possible

But as stated above, problems might ensue: Precision of frame registration, film transport, planarity and film tension etc...

The hybrid solution we went for was to take some critical, mechanical components from an existing projector (that was not up to the task anymore) and to build them into the context/frame we needed. We used:

- the film gate: which ensures stability, planarity and the context for a precise transport

- sprockets: for generic transport and tension control

The key idea we then identified, was to use a simplified claw transport for the film. Therefore we developed a slider that allows precise hysteresis points and added a flexible, shaped wire header as a 'claw'. With this, the setup can have leeway in many components while the result is still super stable.

As a result we have a modifiable assembly of components that are individually interchangeable and give us things such as:

 - switching the gates from S8 to N8

 - easily changeable lens/camera setups

 - complete access to the film

 - little to no bend on the film material before the scanpoint

Together with Dominique's YART the platform delivers very stable and clean scans.

Feel free to have a look at the setup:

https://www.youtube.com/watch?v=y8--CjP7y2s

[adenb...@gmail.com]

Hi Pat,

Just watched your video and it is a super interesting design. Do you have any plans to release the STLs for this?

Best,

Aden

[Manuel Ángel]

Good job, Pat.

I have seen the video and I have been impressed with the way you have carried out the project, with the design and construction of each of the components and the final assembly.

Congratulations on your success.

Manuel Ángel

[Pat]

I've already gotten quite a few responses and requests by email. And yes, I was planning to document & make the system public either as STL or the raw FreeCAD files.

But while we tried to design it to be as generic and versatile as possible, the development forced us to 'get things working'.

The current result still has some drawbacks because of those shortcuts we took and I would like to iron those things out before imposing that on other people.

[adenb...@gmail.com]

That's great and I look forward to checking it out when you make it available.

Obviously it is your project so do as you please, but it would be great if you could make available what you currently have before continuing work. I'm sure you have come across a project before with a "just need to sort some things out before I post it" and then there are no further updates, it would be a shame if that was to happen with this.

Anyway, thanks for sharing!

[Pat]

Yes, but rest assured: The development of the scanner started in march and we're not done yet.

Then, I've just started with the process of scanning around 3.5km of material and I'm pretty sure we will find some things to improve in that journey.

I've gotten quite some leads from dominique and i definitely intend to give something back to the community...

[Dominique Galland]

Projector-less solutions with 3D printing are beautiful pieces of technology and certainly interesting to design and build

Pat's design is truly remarkable

I would still like to say the solutions with a modified projector are still much easier to build.

On the other hand, the projector must be chosen with care :

- Once all the electrical and motor parts have been removed, there must be sufficient space for the lighting and the camera with its adjustment assembly.

- The camera whith its lens must be able to get close enough to the film (depends on the chosen focal length) in direct or reverse mounting

- It should be possible to easily remove the three-blade and fit a toothed pulley on the axls. It's easier if this axis is in a 1: 1 ratio (1turn = 1 image)

- We must be able to remove the framing mask if there is one in the projection window

- The film loading mechanism must be simple and efficient

- It is better if the projector is 8mm / Super8 bi-standard

Obviously the modified projector can no longer be used for normal projection

My ELMO SP or GP  projector was really easy to modify and to use and gave me a perfectly stable image during the capture

I think it can be found for a reasonable price

The only real downside is that it is not possible or quite difficult to release the film in the middle of the reel.

It is also true that the solutions without a sproket pulley as in professional scanners risk less damage to the film or are suitable for damaged films,.

But it is then much more complicated in the software to recenter the image in a stable way.

Dominique

[Pat]

You should listen to Dominique... He is mostly right and i can just second his points and would even add another one:

Make sure the projector you are getting still fully functional and not off the scrap pile: gears or rubber wheels can be partially defect or brittle, old grease can make the mechanical parts turn hard and in general worn parts might lead to your film being damaged when processing it.

On the other hand he also identified the big pro of an open setup: it's much easier to insert and test a film at a specific point and quickly reposition it.

Also, i needed to be able to handle material that cannot be inserted into a projector anymore such as very short pieces of film, reels with broken material, 120m spools etc.