
Binary marble adding machine - ColinWright
http://woodgears.ca/marbleadd/
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huhtenberg
The entire website is incredible. Good find, Colin.

What I don't understand why this is not sold as constructor toy sets? There's
a lack of _simple_ interesting educational toys for 5+ year-olds. These are
just a perfect fit. Just look at the combination lock [1] or the Hui Game toy
[2], for example. What kid wouldn't want to have this? I would buy a good half
of these creations in a jiffy.

† Assuming they are well made and reasonably priced (under $100).

[1] <http://woodgears.ca/combolock/index.html>

[2] <http://woodgears.ca/hui/index.html>

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fnordfnordfnord
This is one of my favorites do to its extreme simplicity:

<https://www.youtube.com/watch?v=zELAfmp3fXY>

Examples in Little Big Planet:

<https://www.youtube.com/results?search_query=lbp+calculator>

Not digital stuff but still neat-o, wooden gears:

<https://www.youtube.com/watch?v=WYcqJ5HdxA4>

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VLM
In a similar vein these completely wooden clocks are somewhat interesting:

<http://www.lisaboyer.com/Claytonsite/Claytonsite1.htm>

I have mostly completed an "Horologium" and then intend to finish the simple
perpetual calendar. The "Celestial Mechanical Calendar and Orrery" is more of
a retirement project, with nothing to compare against its hard to tell that
its about four feet wide by two feet tall, full of cams and gears.

I tend to cheat and cut my axles outta brass on my metal lathe, but the
projects "officially" can be built completely out of wood.

It turns out from personal experience that its pretty easy and fast to cut
wooden gears to shape, but a real puzzler to sand them and finishing is a huge
problem because most finishes look nice but gum up the works if any gets on
the contact area of the teeth. From the outside the challenges simplistically
look to be reversed.

Folks in an "electronic" business like this need a "non-electronic" hobby and
butchering wood is more or less mine at this time, although I mostly make
furniture not clocks. If you're willing to follow the rabbit hole deep enough,
woodworking turns out to be about as deep as computer science. If you think
you know everything there is to know about woodworking, you probably don't
know much about woodworking. Ham radio is like that too.

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pavel_lishin
> _If you're willing to follow the rabbit hole deep enough, woodworking turns
> out to be about as deep as computer science. If you think you know
> everything there is to know about woodworking, you probably don't know much
> about woodworking._

Every once in awhile, I throw up my hands at my computer and tell myself that
I'm going to quit and become a carpenter, instead.

Now I need a new less-ambitious ambition.

~~~
VLM
LOL there's a difference between woodworking and being a carpenter. Probably
90% of carpenters build cookie cutter houses same thing every day. On the
other hand there's probably not very many people in the whole world who know
what ornamental turning and geometric chucks are, much less actually do it.

One wood supply shop nearby me is apparently haunted by people who make wood
pens. That's it. They just make really cool looking homemade pens. They have
tons of gear and parts and supplies specifically for that kind of work.

Another example, there's a guy named Roy Underhill who's been doing mostly
traditional jointery on a PBS show continuously since 1979. Over 400 episodes
and still going. 200 hours just of one obscure historical corner of
woodworking.

Then there's carving, pyrography aka woodburning...

Rather than ambitionlessness I use it to avoid thinking about a problem for
awhile when I get stuck. Not pure procrastination, but there's a whole class
of bugs that can only be identified by a fresh mind and the longer you stare
the less likely you'll see it unless you take a break. Donno if I should be
encouraged or discouraged by all the furniture (and scrap wood) I've made.

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bazzargh
See also the DigiComp II, which could do multiplication:

<http://digi-compii.com/>

They have an enormous one that uses pool balls:

[http://www.evilmadscientist.com/2011/a-video-introduction-
to...](http://www.evilmadscientist.com/2011/a-video-introduction-to-the-digi-
comp-ii/)

~~~
fnordfnordfnord
Thanks for posting this. I've been showing the video from woodgears.ca to my
classes for some time now, and despite having spent a fair amount of time on
Evilmadscientist, I'd never noticed the Digi-Comp.

~~~
ChuckMcM
Its pretty awesome, I played with one at the Maker Faire in San Mateo and the
rhythms of the marbles clicking were fascinating! At some point I am going to
need to record that and put it into a music track.

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mef
Really awesome, what a great teaching tool for binary. When this register
overflows, it really overflows!

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brendanobrien
What a fantastic method for making technology seem less daunting.

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Intermernet
This is possibly the best way to introduce the fundamentals of computer
science to a really young kid I've seen. I'm even thinking of trying to
simulate one...

Anyone got any recommendations for js physics / animation libraries?

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noonespecial
Even if you ignore the binary adding part, looking a the behavior of a single
gate is a fantastic, concrete example of what a flip/flop is and how it
functions.

~~~
joshu
Those are half-adders, not gates or flipflops.

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tocomment
Can someone explain how it works? How does it add something like 5 and 4?
(What do you put in, when, and how do you interpret the output?)

~~~
yebyen
Five would be 4 and 1... since those are numbers that can be represented by a
binary "marble" in the right position, and each of those positions has a slot
in the machine.

So you put a marble into 4 and 1 slots, and let them drop to store a "5" in
the register. Then you put another into the 4 slot and let it drop, it clears
the marble already in 4 through the drop-chute, flipping the flip-flop and
pushing the new marble up from 4 slot to the 8, and you very simply get 9
which is 8 and 1.

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Sami_Lehtinen
How about creating brainf __k engine using marbles and restricted memory
slots? Parts excluding the marbles could be 3D printed etc.

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JacobIrwin
I grew up spending weekends with Grandpa in the workshop. This is great!

