In a message dated 2008/08/25, gel@................. writes:

> My first inclination would be to go with the Sean Thomas Morrissey's 
> concept. It would sure be nice to have a vertical with an equivalent 50ft beam 
> length in a 2 sq. ft space. But the design detail and drift issues would seem to 
> be a problem. 

Hi Gary,

       It takes a bit of sorting out, but it is all there.

As a few mentioned, the Randall Peters design  
> http://physics.mercer.edu/hpage/new-z.html looks interesting. But I have a 
> few questions:
> 
> 1.       What is a capacitive linear position sensor.

       Exactly what it says it is.

       See http://physics.mercer.edu/hpage/rpend.html

       2. If feedback is used

       I don't see any feedback. There could be a magnetic damper behind the 
sensor plates. The horizontal had a magnet damper around the tongue on the end 
of the shield plate. The apparatus in the photo looks more like a 
construction to demonstrate the principles involved.

       Also have a look at http://jclahr.com/science/psn/hill/index.html

       Regards,

       Chris Chapman



   
In a me=
ssage dated 2008/08/25, gel@................. writes:



My first inclination would be t=
o go with the Sean Thomas Morrissey's concept. It would sure be nice to have=
 a vertical with an equivalent 50ft beam length in a 2 sq. ft space. But the=
 design detail and drift issues would seem to be a problem. 



Hi Gary,



       It takes a bit of sorting out, but it i=
s all there.



As a few mentioned, the Randall Peters design  

http://physics.mercer.edu/hpage/new-z.html looks=
 interesting. But I have a few questions:



1.       What is a capacitive linear positi=
on sensor.




       Exactly what it says it is.



       See http://physics.mercer.edu/hpage/rpe=
nd.html



       2. If feedback is used



       I don't see any feedback. There could b=
e a magnetic damper behind the sensor plates. The horizontal had a magnet da=
mper around the tongue on the end of the shield plate. The apparatus in the=20=
photo looks more like a construction to demonstrate the principles involved.=




       Also have a look at http://jclahr.com/s=
cience/psn/hill/index.html



       Regards,



       Chris Chapman