Geneva Pair / Geneva mechanism / Geneva drive / Malteserkreuzgetriebe

3D animation showing Geneva movement in a 35 mm projector and some motion picture cameras (mostly early it would seem). Animation by Andrej Cimerman.
Software: Blender
Websites:
sites.google.com/site/andrejc3d
drejc120.wixsite.com/andrejsc...

[@panditjee1]

Very useful to understand cinema projector process

[@eluridurgamuraliprasad7652]

Great mechanism

[@autopack20]

th-cam.com/video/lvay4qX1pxw/w-d-xo.html

[@abhigowtham7966]

Super video

[@andrejcimerman9640]

Thanks! Really glad you like it.

[@aneeshsreedharan1604]

In the past, when watching a movie, I didn't know the mechanism behind it. It's understand now. But now that projector is not used.

[@andrejcimerman9640]

It's always nice to hear things like that. A lot more work went into making this short animation than its simplicity would suggest. Thank you for giving it a chance. This mechanism has also been used in some of the early cameras.

[@theabbie3249]

What's the point of the carved disk? it's causing unnecessary friction

[@andrejcimerman9640]

The carved disk keeps the driven wheel ("the Maltese cross") in place, when the pin of the drive wheel is not engaging one of the four slots of the driven wheel. Without it the film would keep advancing forward, pushed by the angular momentum of the sprocket wheel that engages perforation of the film.

[@karigori6415]

Blender's real good.
Your animation is better.

[@andrejcimerman9640]

Thank you. Personally, I find that realistic illustrations and animation are actually less clear so I decided for a more simple and illustrative render.

[@karigori6415]

@@andrejcimerman9640, keep up the good work mate.

[@paulykj7140]

The sproket is for 35 mm film? How many teeth in the sproket and it's diameter please?

[@andrejcimerman9640]

As you can see the wheel stops four times per revolution which means four pictures go through the gate each time the axis makes 360 degrees. With so-called 4-perf pulldown, meaning four side perforations per frame, we get 16 teeth on our wheel. The length of the travelled film for four frames gives us the circumference of the wheel. At 16 frames per foot or 19.0 mm per frame (that is exposed area + gap on the upper and the lower edge of the exposed area) gives us 76 mm for four frames. The diameter dimension you seek equals circumference divided by pi. That gives us the diameter of 24.2 mm.
One more thing. This would be the diameter of the rim that has teeth on it, the actual inner cylinder is somewhat smaller since only the perforated edge of the film should should come in contact with the mechanism. The picture area of the film should have as little contact as possible to protect the picture from scratches.

[@paulykj7140]

@@andrejcimerman9640 thank you

[@jensona.v518]

16 teeth. In one rotation totally 4 frame will be pushed. .For the exact diameter, just roll 4 frame of 35 mm film . That will be the exact diameter.

[@arefalizadeh5927]

I need a vidio about how you model this..thanx

[@andrejcimerman9640]

Thank you for your interest. Never would I think that people would have so much interest in something like this. I might try to write a tutorial some time in the future.

[@autopack20]

th-cam.com/video/lvay4qX1pxw/w-d-xo.html

[@roryvonbrutt7302]

movie projector intermittent ! ! !

[@shinemendwoor]

Who is here after their MIDTERM EXAM???

[@andrejcimerman9640]

Is this your way of relaxing or is this video related to something you had to know for your midterms.

[@shinemendwoor]

We had to watch this video to do our exam, if you check the viewing data, there will be a date where your views probably got up by ~100

[@f.s.deewana3710]

फिल्म प्रोजेक्टर