Dewayne,


Good job of finding a spring!  Do you have some photos of your
unit?  I think it would be good

to post some, along with your spring details, on my web site.  Are
you using AmaSeis?  If so,

it would be interesting to save a 24-hour screen image of the next good
sized event.  We could

compare it to one of the local AS1 posted here:


http://jclahr.com/science/psn/as1/heli/allas1.php


Cheers,

John


At 07:49 PM 3/27/2005, you wrote:

I just
completed a homebrew AS-1 seismometer.

 

I must say the most challenging part was trying
to find a boom support spring.

 

Having no engineering degree so I was left to
do the trail and error method. I got very lucky. I just had a new LOWES
lumber/hardware store open very close to me.

 

Being a new store their stock was full and
complete. I found a spring manufactured by Century Spring Corp.

The part number on the package is "C-219". I purchased
two of these springs. 

 

I had to do some resizing of these springs. The
spring is 4.5" long. I cut about 3/8" off of each coil. I then
spread the coils of each spring just far enough apart to mesh them

together (about a 1/2" overlap.)  I happened to have a
1/2" i.d. x 1" spacer in my junk bin so I slid the spacer over
the meshed coils so they will not separate.

 

I ordered a coil and magnet for Larry. The
amplifier is from the following URL

http://users.viawest.net/~aloomis/seismom.htm a power supply
for this amplifier 

can be found at

http://users.viawest.net/~aloomis/seisprea.htm .

 

When I started this project I requested a
catalog from Century Spring. I can not find a spring with a C-219 part
number, but there is a spring with the part

number of 302 that is a very close match. Another spring that
could be tried is the 119. This one would have to be cut to the desired
length. Century Spring has

a minimum order of $30.

 

I must say that the sensitivity appears to be
superb as compared to my Lehman (but it's never been quite right after I
rebuilt it.)

 

All of the mechanical bits were purchased from
LOWES.

 

If you would like more information please
contact me at n0ssy@...........
and not through the PSN list server.

 

 

 

Dewayne Hill 

Westminster, Co.