gfish: (Default)
gfish ([personal profile] gfish) wrote2010-01-04 06:38 pm

getting back in the saddle

I saw a Jacob's Ladder (the little wooden toy, not the electrical arc version) for the first time in years last week, and I realized it was a really neat mechanism. And I started thinking how neat the effect would be if you had a really long one, with an oscillation at the top to keep the cascade constantly going down both sides. Particularly if it was all made out of metal, using bike chain as the connecting links. The clickety-clickety-clickety would sound so pleasing! So I think I might have to do that.

But first, to get a feel for how these things work, I threw one together out of parts I had laying around. It was so nice, having everything right there! Even my 10+ year old collection of random dowels!



I learned a couple of important things from this prototype. First, the action to start a cascade involves lifting the entire chain each time. I had been thinking about an automatic movement, maybe using a pendulum or verge and foliot clockwork. That's just too impractical, when dealing with a ~2 meter long metal version. So now I'm thinking it will be powered with a big hand crank, geared down as needed. Would make a nice interactive piece to stick on the side of the road at Burning Man. It seems to be very resistant to permanent jams, too. The strings can get misaligned and jam, but the next cascade coming down the other side always clears it. And using chain instead of string will keep them better aligned anyway.

So, does anyone in town have a bunch of old bike chain? I'm not sure where to find that, and it seems silly to pay for it new. As long as it isn't rusted solid, I can use it.

[identity profile] anansi133.livejournal.com 2010-01-05 03:12 am (UTC)(link)
You might find a sympathetic bike shop to donate some chain, changing out the chains is a frequent tune-up item.
solarbird: (Default)

[personal profile] solarbird 2010-01-05 04:17 am (UTC)(link)
Yeah, such as: UW bike shop, Recycled Cycles.

inspiration

[identity profile] feylike.livejournal.com 2010-01-05 04:26 am (UTC)(link)
i recommend the following as inspiration: http://www.timeshapes.com/

Re: inspiration

[identity profile] zzyzx-xyzzy.livejournal.com 2010-01-05 05:47 am (UTC)(link)
that's a grasshopper escapement!

[identity profile] neuro42.livejournal.com 2010-01-05 05:13 am (UTC)(link)
Hm, now I'm ensivioning one made from full sheets of plywood...

[identity profile] stolen-tea.livejournal.com 2010-01-05 04:01 pm (UTC)(link)
Maybe a hand crank plus flywheel, so that it keeps going for a while after the cranking stops?

[identity profile] gfish.livejournal.com 2010-01-05 09:31 pm (UTC)(link)
Ooh, I like that idea. That would be very satisfying.

[identity profile] stolen-tea.livejournal.com 2010-01-06 03:52 pm (UTC)(link)
Mmmm, giant flywheels...