Mesmerizing videos of curve-drawing machines


#1

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#2

nephroids, deltoids, astroids, and lemniscates of Bernoulli.

I love the names of these things. Kampyle of Eudoxus! Witch of Agnesi! I keep expecting someone to write an RPG where they’re all fierce creatures or summoning spells or something.


#3

See also:


#4

But I had an actual mechanical version that could do all these things 40 years ago.


#5

The ones with strings are the best.


#6

I still have mine, plus the Super Spirograph.
Right next to my ~50 year old Etch-a-Sketch.


#7

If you like these, you’ll probably like this book as well. It has many interesting mechanical means for drawing straight likes, or almost straight lines. A combination of mathematics, engineering, art and philosophy.


#8

Great book. The author has a video on line of actual physical constructions of some of the concepts:
How Round Is Your Circle?


#9

These are a lot of fun. I especially like the complex circle machine that draws a straight line.

I have built clocks using the Lissajous method of drawing circles on an oscilloscope. There’s analog electronics that makes the sine and cosine waves that comprise the circles; the microcomputer just positions them and controls the enabling of each octant. Lines are made of cosine waves.

I’m working now on getting it back into production.


#10

my avatar–

was made by me with a vintage super spirograph set–


#11

According to the book that @Jim_Kirk mentioned, it’s a serious problem-- mostly because straight edges aren’t


#12

Thanks for posting this, these videos will be useful in the classes I teach. I cover many of these curves but only from the equations, there are only a few where I can do a convincing job demonstrating the motivation for them using the tools at hand (chalk, string, waving hands).


#13

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