wrote:
> Folks,
> I am building a vertical seismometer based on drawings put together by Kay
> Wyatt (with help from Chris Chapman), it uses a piano wire hinge and the
> coil is attached to the boom. My current problem is locating a spring for
> this thing. I have found one at the local hardware store, it's long enough
> (about 14") but it's pretty large in diameter and perhaps a bit too stiff.
> I have tried to contact Kay but have had no luck. I work in a middle school
> here in Portland (I'm the tech support person) and we have 2 AS-1's that I
> maintain. Their springs are much smaller in diameter. So I am wondering if
> any one on the list knows where, or how I would go about obtaining such a
> spring.
> I might mention that I have built two horizontal seismometers based on the
> design that Chris Chapman helped to design in England for use in schools.
> They use crossed carbide rods for hinges. I wound my own coils and hope to
> have them up and recording within a year (being realistic here, as I have
> been working on all three seismometers, on and off for almost a year
> already). So I may be asking more questions!
> Thanks in advance for any help. You can respond here or email me direct:
> tdavisjb@............
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSNLIST)
>
> To leave this list email PSNLIST-REQUEST@.............. with
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> See http://www.seismicnet.com/maillist.html for more information.
>
I built the same sensor from Kay's drawings and it is in operation=
at this IRIS=A0site. The helicorder updates every 5 minutes.
=A0
=A0
Here are some pictures of my sensor. You will notice some differences =
in the coil used and the attachment points of the music wire.
=A0
=A0
Also, my first copy of an AS-1 sensor is located here.
=A0
=A0
They both mirror each other as far as performance. Not much difference=
that I have been able to note.
=A0
The best place I found for springs is from Reid Supply. Extension spri=
ng ES-218 resulted in a natural period of 1.8 seconds. You can order as man=
y springs as you want and return what you don't use. I ordered $40.00 w=
orth and it was a great way to choose from several I picked from their on l=
ine catalog.
=A0
=A0
I found that if the music wire hinge is too small in diameter, there w=
ill be a considerable amount of lateral movement of the boom. I settled on =
a .18 Ernie Ball guitar string purchased for $1.13 at the local music store=
..
=A0
The coil pickup is from a 220 VAC relay. With the N42 magnet block, th=
is sensor puts out nearly 4 times the voltage of=A0my=A0horse shoe=A0magnet=
AS-1 sensor.
=A0
And if=A0you want a great place to=A0buy=A0pre-cut metal for your proj=
ect, On Line Metals=A0is the best.
=A0
=A0
Rich Schneider
KCMA IRIS
=A0
=A0
=A0
=A0
I used a ES
=A0
=A0
=A0
=A0
=A0
On Thu, Nov 17, 2011 at 9:37 PM, tdavisjb
<tdavisjb@...........
t> wrote:
Folks,
I am building a vertic=
al seismometer based on drawings put together by Kay
Wyatt (with help fr=
om Chris Chapman), it uses a piano wire hinge and the
coil is attached to the boom. My current problem is locating a spring forthis thing. I have found one at the local hardware store, it's long e=
nough
(about 14") but it's pretty large in diameter and perhaps=
a bit too stiff.
I have tried to contact Kay but have had no luck. I work in a middle school=
here in Portland (I'm the tech support person) and we have 2 AS-1=
39;s that I
maintain. Their springs are much smaller in diameter. So I a=
m wondering if
any one on the list knows where, or how I would go about obtaining such aspring.
I might mention that I have built two horizontal seismometers =
based on =A0the
design that Chris Chapman helped to design in England fo=
r use in schools.
They use crossed carbide rods for hinges. I wound my own coils and hope to<=
br>have them up and recording within a year (being realistic here, as I hav=
e
been working on all three seismometers, on and off for almost a year
already). So I may be asking more questions!
Thanks in advance for any h=
elp. You can respond here or email me direct:
tdavisjb@............
____________________=
______________________________________
Public Seismic Network Mailing List (PSNLIST)
To leave this list=
email PSNLIST-REQUEST@SE=
ISMICNET.COM with
the body of the message (first line only): unsubsc=
ribe
See h=
ttp://www.seismicnet.com/maillist.html for more information.