World's Simplest Electric Train
February 28, 2017 6:20 AM   Subscribe

A cool little science project to try out. How it works.
posted by Foci for Analysis (14 comments total) 29 users marked this as a favorite
 
If Radio Shack was still down the street, I'd be there right now buying supplies to make this. Very cool project for kids.
posted by james33 at 6:25 AM on February 28, 2017


Very cool.

If anyone has a link to magnets that are the right size, conductivity, and strength for doing this, please post a link. TIA!
posted by alms at 6:27 AM on February 28, 2017


alms, just google 'rare earth disc magnets'. An AA cell is about 14mm in diameter. I'd probably go for 16 or 17mm magnets to ensure they're sufficiently wider than the cell. Plenty of places to order them from (e.g. magnets365)
posted by pipeski at 6:43 AM on February 28, 2017


Nice! this is a bit like a non-levitating version of Inductrack!
posted by rum-soaked space hobo at 7:08 AM on February 28, 2017


Thanks OP. This is the kind of little spark of Joy that made me sign up to metafilter in the first place
posted by Faintdreams at 7:11 AM on February 28, 2017 [4 favorites]


Totally doing this!
posted by dowcrag at 7:38 AM on February 28, 2017


Isn't Elon Musk planning to build one of these big enough to carry people?
posted by Bringer Tom at 8:00 AM on February 28, 2017


How it works
posted by rocket88 at 8:18 AM on February 28, 2017 [1 favorite]


That is so cool. And here I am using fossil fuels like a sucker.
posted by Mchelly at 8:49 AM on February 28, 2017


The notes under the video (if you watch it on YouTube instead of the pop-up window) go into more details on how to make it, including a link to a "how to make it" video.
posted by Greg_Ace at 8:51 AM on February 28, 2017


I appreciate that when there were two coming out of the same track he quickly moved the first one out of the way to avoid a collision.
posted by aubilenon at 9:20 AM on February 28, 2017 [2 favorites]


Me too, although I realized that my first assumption - the two sets of batteries/magnets would collide - is probably not likely, since according to the "how to make" video the North pole of the magnets is facing outward at both ends, so the two battery/magnet sets would repel each other rather than connect. My next assumption is that the first battery/magnet set, if left right at the exit of the coil, would try to repel the second set back into the coil, not letting it move forward and, I dunno, overheating the second battery maybe? (IANAEE).
posted by Greg_Ace at 9:30 AM on February 28, 2017


By my reckoning if the batterymobile were to be stopped you'd be getting about 7 amps through the circuit, with about 3 watts dissipated by the wire coil and about 8 watts dissipated by the battery's internal resistance (the resistance of the neodymium magnets is negligible). So assuming I'm in the ballpark overheating probably wouldn't be a big issue.
posted by clorox at 3:58 PM on February 28, 2017 [1 favorite]


Oh. Well then, maybe he's moving the first one out of the way because he's excessively tidy or something..
posted by Greg_Ace at 4:06 PM on February 28, 2017


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