The Geneva Mechanism

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[HermanManly]

This is what Youtube was made for. Information by enthusiastic people teaching about obscure things that you would have difficulty specifically researching or even finding unless you're interested in it already. Beautiful.

[markprice]

The Geneva drive is used in the 7.62mm and 30mm chaingun that is fitted to many armored fighting vehicles and helicopters.

[FairburnD]

25 mm Bushmaster Cannon. Firing cycle of operation...Sear, Feed, ram, Fire, "Dwell", misfire, extract. Common Weapon System on Light Armored Vehicles.

[larrywestenberg]

You are an excellent "natural teacher." You communicate an attitude of, "Hey! Check this out!" and it keeps me interested. You did a great job of showing me where and how this thing works. I write training for a living. You really have a talent for this!!

[JustinBishop]

This is the pure side of Youtube. I enjoy

[ugh]

that blows my mind! i've always wondered where the clicking sound in old film projectors came from

[ContinuumOfHarmony]

Military use: syncing weapons fire with the propeller blades of an air craft so pilots could aim using the main body of it.

[JustinBarylski]

Why was this in my recommended, why am I watching it and why do I like it so much? I suddenly have a huge fascination with gears and simple machines like this...

[Inesophet]

Youtubes algorythm got better, i didnt even know im interested in this...but well. Now i do.

[Ncyphen]

As a former projectionist, I can tell you that the sound from modern film projectors was not caused by this drive. If you ran the projector drive, you hear a slight clatter, as to be expected of the intermittent rollers. Most of the clacking actually came from the film expanding and shrinking due to the intermittent gear.

When a projector is threaded, a small excess loop is left above and below the aperture, as the project feeds film into the projector continuously; however, the film has to stop for the slit second light hits the aperture to create a clear picture on the screen. The loops above and below the aperture expand and shrink rapidly due to this stopping motion and create the known sound of the projector clacking.

[OldTooly]

All of our (now antique) Peerless Roll Leaf machines used a Geneva drive to index the next bottle into printing position. They ran 3 shifts for over 30 years with nothing more than a touch of grease from time to time. The were a quality cast iron construction and were fitted so closely that there was a very minimal orientation error that never seemed to increase over time. A truly remarkable design. Later machines used Camco Units and were very good as well but still a step down from the ultra simple Geneva drives. As a 5 year apprentice Tool Maker I was given the task of building one of the Peerless machines from a pile of scrap machine parts which required making a Geneva drive from scratch and rebuilding all the other moving parts with brass inlays and braze-ups and refit. No time limits (that I knew of) and a few weeks later I presented the finished machine to the General Manager of the printing department. He and his setup people and operators went over it with a fine tooth comb and gave me a thumbs up. The old Tooly's I was training under all gave me a round of applause when I came back to the department, a hand shake and an atta boy. One of the proudest moments of my 47 years as a Tool Maker. All manual machines and hand tools. Computers hadn't been invented yet except in big research facilities. I'm not sure that today's machinists will ever have any experience like that. For that I am truly sad.

[Mike]

As a protectionist on Christie protectors, we called the intermittent gear the Star Drive lol 😆

[xader.s]

i have not watched ANYTHING related to this video yet for some reason
it Recommended this to me




fine youtube you win

[tompinion]

Fascinating. I love how your channel is so packed with information. Very entertaining.

[jasonreed]

Much of the sound you hear in a film movie projector is the sound of the film being quickly advanced to the next frame by this mechanism as well as the shutter opening when the next frame on the film has been positioned briefly before being snapped closed again so the film can be advanced another frame. The film is kept with a certain amount of slack before the frame that is currently being shown on the screen. When the mechanism advances to the next frame, this slack is temporarily taken up, making the loudest contribution to the sound you hear when a move projector is playing a reel of film. This is why the projector is much quieter when you first turn it on to feed the film through the projector. The Geneva drive is still operating, but once the stiff film is fed through, the film its self makes all of the racket the way it is handled by the Geneva drive mechanism. Thank you fire sharing! I learned something new today! :)

[CJ]

I repaired film 8mm and 16mm projectors for many years. I saw the Geneva movement only in a few high-end theater-style 16mm projectors. Compared to the more common mechanisms in most other projectors, I found the Geneva mechanism much less prone to wear and problems than the common cam and follower setups in other machines. Geneva was a lot easier to fix too. If you think the Geneva movement is "violent, " you should see the cam and follower stuff in other 8mm and 16mm units! Most of those wore out very quickly. Cams, followers, belts and rubber idlers were the bulk of what I had to replace regularly. Sound and lighting (especially xenon arc) were also problem areas.

[shafey]

I really like those 'Look at this nifty mechanism!' videos you make. Like the one about the not-a-crank crank.

[jerrylong]

I used to repair machinery that assembled trigger sprayers, ( think windex or 409 cleaner). Some of them used a Geneva wheel to place the cap in position. A very robust and elegant mechanism. They very rarely needed repair. The pin was a roller so not much problem with wear. 1 cycle per second 24 hours a day.

[killermetalwolf]

me: *sees title*

me: what section of the geneva convention does this break?

[RoboRobotnik]

If you're looking for military application, the rotating-barrel gatling gun spins to reduce heat wear on the barrel and uses a similar mechanism to hold the barrels in place while the bullet is traveling through it, rotating to the next barrel once it's clear.