PSN-L Email List Message

Subject: Re: Spring for AS-1 type vertical seismometer
From: Richard Schneider cfi2fly@.........
Date: Sun, 20 Nov 2011 11:14:29 -0800


I built the same sensor from Kay's drawings and it is in operation at this
IRIS site. The helicorder updates every 5 minutes.

http://www.iris.edu/amaseis/schools/as1imgs/KCMA.png

Here are some pictures of my sensor. You will notice some differences in
the coil used and the attachment points of the music wire.

https://picasaweb.google.com/104538830969366424160/AS1TypeSeismometerImproved?gsessionid=BgcvlV9x2C1QAGkvXm5tlw
#

Also, my first copy of an AS-1 sensor is located here.

https://picasaweb.google.com/104538830969366424160/AS1TypeSeismometer02#

They both mirror each other as far as performance. Not much difference that
I have been able to note.

The best place I found for springs is from Reid Supply. Extension spring
ES-218 resulted in a natural period of 1.8 seconds. You can order as many
springs as you want and return what you don't use. I ordered $40.00 worth
and it was a great way to choose from several I picked from their on line
catalog.

http://www.reidsupply.com/products/tooling-components/springs/extension-springs-accessories/extension-springs/

I found that if the music wire hinge is too small in diameter, there will
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.

The coil pickup is from a 220 VAC relay. With the N42 magnet block, this
sensor puts out nearly 4 times the voltage of my horse shoe magnet AS-1
sensor.

And if you want a great place to buy pre-cut metal for your project, On
Line Metals is the best.

http://www.onlinemetals.com/

Rich Schneider
KCMA IRIS




I used a ES







On Thu, Nov 17, 2011 at 9:37 PM, tdavisjb  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
> the body of the message (first line only): unsubscribe
> 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
http:= //www.iris.edu/amaseis/schools/as1imgs/KCMA.png
=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
https://picasaweb.g= oogle.com/104538830969366424160/AS1TypeSeismometerImproved?gsessionid=3DBgc= vlV9x2C1QAGkvXm5tlw#
=A0
Also, my first copy of an AS-1 sensor is located here.
=A0
https://picasaweb.google.com/104538830969366424160/AS1TypeSei= smometer02#
=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
http://www.reidsupply.= com/products/tooling-components/springs/extension-springs-accessories/exten= sion-springs/
=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
http://www.onlinemetals.com/<= /a>
=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.


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