[dorkbotsea-blabber] Science fair - earthquake - help

[Joe Benner]

Hi Toby,
I have one of the galvanometers that showed up at weird science (and also at
House of Science) a couple years ago. I don't know if you've seen them. It's
a DC motor with a 3 inch needle that pivots on the motor's shaft. The needle
is for writing on thermal paper with. I just ran 5V through a 10K pot to the
motor. I turn the knob on the pot and the needle jumps proportionately.

Basically the whole thing could be made to look (even act) like a
seismograph pretty easily.

You could probably tape a ball point/felt tip pen filler tube thingy to the
needle. 

I think you could probably run it right off an analog input (maybe with a
just transistor to amplify and/or some added resistance).

The assembly also has a paper feed roller for a tape about 2 in. wide - like
a cash register tape.

It's yours if you want it. 

I'm in Tacoma - there is a good chance someone in Seattle has one they might
be willing to pass on to you too. 

Joe

-----Original Message-----
From: dorkbotsea-blabber-bounces at dorkbot.org
[mailto:dorkbotsea-blabber-bounces at dorkbot.org] On Behalf Of Toby Paddock
Sent: Wednesday, October 04, 2006 6:49 PM
To: 'A discussion list for dorkbot-sea'
Subject: [dorkbotsea-blabber] Science fair - earthquake - help

My son is doing a science fair project on a table-top earthquake machine.
I'm looking for a CHEAP and especially EASY way to capture and display
seismic waveforms on a computer. Most of what I'm finding on the web for
amateur seismology is either expensive or pretty complicated. And I'm pretty
cheap and lazy.

I'm not worried about the sensor. We can use a MEMS accelerometer or
coil/magnet or even a geophone if I can find one. No problem. And it doesn't
have to be real sensitive or calibrated.

But the a/d and the software I don't know about. I couldn't program my way
out of a paper bag, so simple is good. 3 channels of a/d would be great, 2
would be fine, and 1 would be OK. If the software ran on win95, I could use
my $5 garage sale laptop.

The earthquake stick/slip model thing is something like this:
http://quake.wr.usgs.gov/research/deformation/modeling/eqmodel.html

Thanks,
Toby


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