In a message dated 2008/02/14, PETERS_RD@.......... writes:

> Those of you who like to build things might want to try your hand at a new 
> design for the old LaCoste spring vertical seismometer. 

Hi Randall,

       I note that you mention using a zero length spring. The extension 
springs that you can buy do not have such a high preload - usually about 1/3 of 
that required. Are you winding your own?

       What hard counterface are you using for the WC 1 mm bearings? They 
have quite a restricted load carrying capacity (100 gm?), but, unlike the 
Volksmeter, the seismic mass is quite heavy.
 
       How does the seismometer cope with vertical inertial loads of up to 
0.1 g and horizontal loads of an appreciable fraction of this? How do you avoid 
overloading these very small bearings? What is supposed to maintain the 
horizontal positional stability? While a vertical seismometer is only sensitive to 
vertical loads, it experiences both vertical and horizontal displacements while 
in operation.    

       Regards,

       Chris Chapman   
In a me=
ssage dated 2008/02/14, PETERS_RD@.......... writes:



Those of you who like to build=20=
things might want to try your hand at a new design for the old LaCoste sprin=
g vertical seismometer. 




Hi Randall,



       I note that you mention using a zero le=
ngth spring. The extension springs that you can buy do not have such a high=20=
preload - usually about 1/3 of that required. Are you winding your own?



       What hard counterface are you using for=
 the WC 1 mm bearings? They have quite a restricted load carrying capacity (=
100 gm?), but, unlike the Volksmeter, the seismic mass is quite heavy.

 

       How does the seismometer cope with vert=
ical inertial loads of up to 0.1 g and horizontal loads of an appreciable fr=
action of this? How do you avoid overloading these very small bearings? What=
 is supposed to maintain the horizontal positional stability? While a vertic=
al seismometer is only sensitive to vertical loads, it experiences both vert=
ical and horizontal displacements while in operation.    



       Regards,



       Chris Chapman