Lego film cleaning machine.

[slashmaster]

For those of you who might be new here, if you go back far enough on this forum you can find a post about a super 8 projector someone made of legos. It had very poor registration but it worked! So I thought I'd try something similar. I just finished a film cleaning machine kind of like the "Film-O-Clean". I wanted to get the Film-O-Clean but they cost about $400. So I built my own out of Lego's! It's not perfect yet but I was in a "just get it done" mood. If anyone knows what the proper gear ratio for one of these is please let me know! https://www.facebook.com/media/set/?set ... 883&type=3

[milesandjules]

Hey I like it

[slashmaster]

Thanks MilesandJules! I've got a certain film I've run many times through it. It seems all in all cleaner but doesn't seem to do anything about the biggest specs of dirt. I might have to stop the projector to do those manually with a q tip.

[granfer]

There is no "proper gear ratio" as this depends on the way you are making the media roll move in YOUR particular machine . Are you using Filmtech media rolls? How long is the tape in each roll? With that information I can tell you how to arrive at your "proper gear ratio" for YOUR machine.

[slashmaster]

There is no "proper gear ratio" as this depends on the way you are making the media roll move in YOUR particular machine . Are you using Filmtech media rolls? How long is the tape in each roll? With that information I can tell you how to arrive at your "proper gear ratio" for YOUR machine.

I tried to order the film tech media rolls but they didn't send them. So instead I cut lens cleaning tissue into strips and attached each end to the next with double sided tape. So I can make it as long as I want. I think my current gear ratio is using about 5 inches of media cleaner for every 100 feet of film.

[granfer]

The FilmTech film cleaning system works by having a “Media Pad” in contact with the moving film. In order to ensure that there is no build up of dirt on the Pad it takes the form of a “tape” continuously moving in the opposite direction to the film, thus always presenting a clean surface at the contact point. The movement of the film around a friction drum (or sprocket) is transmitted via a reduction gear to a”take up” spindle which pulls the tape at the required speed as it takes it up.

The required gear ratio depends on …
1. The film speed.
2. The desired media tape speed.
3. The diameter of the “film driven” drum (or sprocket), and
4. The diameter of the take up spool hub.

The Media Rolls used by the Kelmar (or Film-o-Clean) machine are 16ft long and designed to last 3 1/2 hours in one run. Therefore, the media moves at an average speed of 0.076 ft/min.

Using this figure as a minimum figure we have the following calculation:

Rotational speed of the “Film drum (or sprocket)”, R = S / pi x D where S is film speed (Ft per minute) and D is the drum diameter in Feet.

Rotational speed of the “take up spool hub” r = 0.076 / pi x d , where d is the hub diameter in Feet

Required gear ratio, R/r is given by S x d / D x 0.076

Any ratio less than this figure will simply move the tape faster in proportion. The tape can be used dry or with cleaning / lubricating fluid.

NOTE: It is admissible to measure D and d in inches or mm, so long as BOTH are in the same units !