In a message dated 09/04/2009, tchannel@............ writes:

Hi Chris,  I know how the roller on roller works, but I can't find a  
picture close up of one.   Do you know of one?   I was  trying to explain it to 
someone, and picture would  help.



Hi Ted,
 
    Sorry, but I don't personally have a photo of the  SEP bearings up 
close. And Charles hasn't included one in 
_http://www.myeclectic.info/SeismoPivots/seismopivots.htm_ 
(http://www.myeclectic.info/SeismoPivots/seismopivots.htm) 
 
    The usual setup is to mount the vertical roller in  a shallow V slot on 
the frame. The horizontal roller is mounted in a V slot on  the end of the 
arm and it is held in frictional contact by the axial load  along the arm. I 
have also used the shanks of 1/8" OD Tungsten Carbide drills.  You can also 
use hardened martensitic SS rod, but you need lap and polish  it after heat 
treatment. I glue the rods with two component acrylic  adhesive, but they 
can also be clamped.
 
    The horizontal roller simply rolls around the  vertical roller. The 
centre of rotation is the centre of the vertical roller.  The crossed 
orientation is maintained by the arm suspension.
 
    Have you looked at the SEP Manual? There are some  photos there, but 
the black painted Al frame is not helpful 
_http://www.bgs.ac.uk/education/school_seismology/seismometer.html_ 
(http://www.bgs.ac.uk/education/school_seismology/seismometer.html)  This  is the UK school seismometer.
 
    Regards,
 
    Chris






In a message dated 09/04/2009, tchannel@............ writes:

  
Hi Chris,  I know how the roller on roller works, but I can't=
 find a 
  picture close up of one.   Do you know of one?   I=
 was 
  trying to explain it to someone, and picture would 
help.

Hi Ted,
 
    Sorry, but I don't personally have a photo of=
 the 
SEP bearings up close. And Charles hasn't included one in http://w=
ww.myeclectic.info/SeismoPivots/seismopivots.htm
 
    The usual setup is to mount the vertical roll=
er in 
a shallow V slot on the frame. The horizontal roller is mounted in a V slo=
t on 
the end of the arm and it is held in frictional contact by the axial=
 load 
along the arm. I have also used the shanks of 1/8" OD Tungsten Carbide dri=
lls. 
You can also use hardened martensitic SS rod, but you need lap and po=
lish 
it after heat treatment. I glue the rods with two component acrylic=
 
adhesive, but they can also be clamped.
 
    The horizontal roller simply rolls around the=
 
vertical roller. The centre of rotation is the centre of the vertical roll=
er. 
The crossed orientation is maintained by the arm suspension.
 
    Have you looked at the SEP Manual? There are=
 some 
photos there, but the black painted Al frame is not helpful http://www.bgs.ac.uk/education/school_seismology/seismometer.html&nbs=
p;This 
is the UK school seismometer.
 
    Regards,
 
    Chris