In graphic design you'll sometimes see a design

with like, three or more gears that are supposed to be meshing together

sometimes what you see

I-I guess I'll draw just sorta wheels like this

but they are supposed to have teeth like this

and then there will be another one here

and another one here

and this is supposed to be like

y'know three things that are working together

the students and the teachers and the parents all come together

to make this school work fantastically, or whatever it is

and you look at this thing

and if you think about what happens with gears

alright so-so if this one is going this way

then because these two the teeth are meshing this way

this one has to go this way

so that they, you know, because they have to turn against each other

and then whats this one supposed to do?

this one is saying that it's supposed to go around that way

and this one is supposed to [be] saying it's supposed to be going around this way

so nothing works, and so your school district grinds to a halt, or whatever it is.

If you happen to have a British two pound coin and you look on the back of it, you'll see there is this design

with gears, and various other things about technology and the industrial revolution

So, if you look closely, there's like 19 --well if you count them--

I guess you can't look and immediately count 19

But if you count them, right, there's 19 of these gears and 19 is odd

So like it goes this way, it goes this way, it goes this way

Odd means that it wont work. So, you know, your symbol of technological process, or whatever; it doesn't move.

So the question is, well, how do you get three gears that do move?

Is there a way to change the shape?

Like, you can't do in the plane, but if you go out of the plane, then what can you do?

So here's a few mechanisms that shows ways you can make this to go

So, these are, like worm gears. You get this, sort of, screw helix thing

And then the way that they work... Well you can see that it works and they are all, sort of, symmetrical around...

Let's see, maybe if you look directly down here, you can see that there is a symmetry between them.

RIght, so these three, sort of, worm gears... Because the way that they interact,

they don't have a direction in the same way as planar gears do (gears just on the plane)

and so you can get them to all work like this

although you do require this frame.

So this is another solution to the problem. It wasn't really a problem that needed solving, but there you go!

So this is, again, it's three gears that turn together, and they are, sort of, meshing with each other.

They have this other weird feature that they're all linking with each other. So they're sort of linked gears.

They stay in place. You can't actually turn one of them without turning all of them at once.

It doesn't move.

It's me and Saul Schleimer, it a guy who I work with these things.

So we made this thing and immediately people say

"Okay. Sure. You can make it go. But can you, like, drive it with a motor?"

And then, what we ended up figuring out is, like... So here's another, sort of, helical worm screw thing

and then. Whoops. So you can see that it's sort of climbing down and as it's going, it is making them go.

So, to answer the question about how do you make it drive itself...

So here's this, sort of, base that you can put it on.

And the gears just sort of slide in there. And then, if you pull this through, then it makes it go.

Or if you just turn it.

This helix thing turning is, sort of, the same thing as moving it, as translating it

So, if you turn it, it makes the gears go.

Or if you push it through, it also makes the gears go.

*grinding sound*

This is, sort of a... ...another variant on that same idea.

These gears aren't rotating gears, they are, sort of, sliding gears.

All of these have, like a, an axis of symmetry. So, there you go.

So... *scoff*

So these... I mean you can see these teeth that make it do that.

Let's see if I can do this weird thing. Let's see. So...

So the illusion, if I move it just right, is that the one I'm not holding doesn't move.

I don't know if you're getting that. So the one that I'm not touching is supposed to sort of hover in the mid air

And while the other ones move. It's, sort of, a weird effect because...

...cause it doesn't look like I'm directly controlling it.

I don't know how good I'm doing that.

You can fix this in post, right? You can just stabilize on it?

Then you'll be fine! Right?

Brady: *giggles*

...of the gaps between the primes as well. You see that some are short...

*ticking*

Oh, that was nice! That was satisfying! A nice long gap. It's really nice!

I mean, it's a bit of silly fun. There is no practical use to anything, but I love it!

*ticking*