Biggest reduction ratio gearing ever build

[MattiJ]

https://www.youtube.com/watch?v=Apqf...re=emb_rel_end

Doesn't look like that much on first thought but when you multiply the numbers its pretty crazy. There is not enough energy in universe to rotate the input gear for enough long to make the output turn one single rotation. 😁

[AntonLargiader]

There's a system like that at the Richmond Museum of Science and Nature. It's a harmless-looking enough set of gears, but a bit humbling when you realize you won't live long enough to see the last one move.

[danlb]

It's always astounding to be reminded of the power of compounding. A 10:1 reduction 100 times is Awfully slow. I wanted super slow feed for my lathe so I set up a 20:127 compound and a 24:100. That gave me 26:1 reduction to add to the gearbox reduction and a final feed that was really, really slow, around 1/400th of an inch per revolution.

Dan

[MattiJ]

It's always astounding to be reminded of the power of compounding. A 10:1 reduction 100 times is Awfully slow.

Dan

Yep. Awfully slow is understatement. 10E+100 reduction ratio.
Current estimate for age of universe is 14 billion years or 4.4E+17 seconds.
If you started to turn that compound gearing at 1 million revolutions per second! at the same time as big bang occured the final gear would have rotated 10E+100/4.4E+23 = some nano-pico-nothing degrees so far. 0.000 degrees and change since big bang. (75 zeros after comma.) 😁

[Baz]

It's always astounding to be reminded of the power of compounding. A 10:1 reduction 100 times is Awfully slow. I wanted super slow feed for my lathe so I set up a 20:127 compound and a 24:100. That gave me 26:1 reduction to add to the gearbox reduction and a final feed that was really, really slow, around 1/400th of an inch per revolution.

Dan

That;s kind of course for a fine feed, 16 BA thread is only 1/3 that tpi

[nickel-city-fab]

That;s kind of course for a fine feed, 16 BA thread is only 1/3 that tpi

Well, since it does depend somewhat on the tool nose radius, I like to use one-seventh of a millimeter for a fine feed.

[danlb]

That;s kind of course for a fine feed, 16 BA thread is only 1/3 that tpi

It sounds like you are saying that the 16 ba thread is 1200 TPI. Yes, that's pretty fine. Or are you saying that 16BA is 160 TPI? Either way, the slow feed worked for what I was doing. Now if I could just remember why I needed that.

[lynnl]

Well now wait a minute. If they're perfect gears, with no backlash, wouldn't that last start turning, at some incredibly slow rate to be sure, as soon as the first one starts?

[epicfail48]

Well now wait a minute. If they're perfect gears, with no backlash, wouldn't that last start turning, at some incredibly slow rate to be sure, as soon as the first one starts?

I think the marvel isnt that it doesnt turn, its that the final gear doesnt turn in a way that humanity can really measure, minus some really fancy metrology equipment. Same sort of thing as calling a surface plate flat, its not flat, we just cant measure how not flat it is easily.

Wonder how long a lever you need on that final gear to back-drive the entire assembly... A 1:10E+100 speed increase sounds like a fun way to hit relativistic speeds!

[MattiJ]

Well now wait a minute. If they're perfect gears, with no backlash, wouldn't that last start turning, at some incredibly slow rate to be sure, as soon as the first one starts?

Flex and minuscule teeth bending would mask any movement for gazillion years.

Tooth in last gear would move lot less than atom diameter in billion years making it impossible to detect even if everything was infinetely stiff and perfect.

[wierdscience]

Oh, there is backlash alright, probably a million years worth in fact.