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Topic: Cycloids doodle on a coffee cup sleeve (Read 800 times) previous topic - next topic

liudr

Not very related to arduino. I was drinking a cup of Einstein bros coffee today over lunch and noticed the doodle on the sleeve was like cycloids (had to google a few time to get this exact term :smiley-roll-sweat:).

Until recently I didn't know a whole a lot about these cycloid curves, although I briefly talk about it in my intro physics in rolling (I knew enough for brief mentioning 8)). I thought I should investigate these curves a bit more. After some more serious investigation, I think:

The top doodle is when you are skidding on ice and put your car on reverse then slam on the gas.
The bottom doodle is when you are skidding on ice and slam on the gas trying to power through the icy road.

Here's a simulation. There is no way to reverse the rotation of the wheel in the simulation so you can't get the top doodle.

http://www.cut-the-knot.org/pythagoras/cycloids.shtml

I guess you learn something everyday, even during some routine things.

To relate to arduino, I wonder if anyone has made an arduino project to keep an object upright when it is on a rotation wheel, like some counters on a bus wheel, always upright, so it won't make these cycloids.  :smiley-roll-blue:

Any others want to comment on cycloids or unexpected learning experience?  ;)

focalist

#1
Mar 20, 2012, 02:40 pm Last Edit: Mar 20, 2012, 02:43 pm by focalist Reason: 1
Classic Cycloid based toy.. I'm POSITIVE you had one.

"Spirographs" are based upon Cycloid motion and math :)

Cycloids are also good things to run with a plotter that's pen-down all the time.  Cool patterns for little code; the demo videos of my Frankenbotic Thinganator, it's drawing a cycloid on a dry erase board!

http://www.youtube.com/watch?v=puoAsZ_kQD0
When the testing is complete there will be... cake.

liudr

Ha ha ha fun! I saw this thingenerator you post a while back. Now a few of my students are intrigued/properly motivated with extra credits to simulate cycloids in software. Will post some results when they hand their simulations in. I'll think about the spirograph too. It's limited to one sheet of paper so ideal for doodling kids to not draw on your wall :)

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