Hi guys, I've been considering making a seismograph. I wanted to make a simple mechanic one at the beginning, so I started browsing how are these things actually made and all the internet was telling me I need so-called zero length springs. (Those are springs that would exert zero force if they had zero length, theoretically. However most springs' force vs length graph looks so that they would exert zero force with bigger than zero length) But I couldn't find any of these springs being sold, so I want to ask you if you know whether or not are such springs even manufactured, and if yes, if you know where to buy them.

 

https://www.researchgate.net/figure...-spring-from-a-positive-free-length-spring-ie

 

seems usable, thanks

 

I've been in the field of seismology (as an electronic tech - not a geologist) since I was a teenager back in the mid 1960s.

The photo in my avatar is one of the seismographs operated by Cal Tech in the 1950s and 70s and I also acquired a lot of surplus parts from Lehner & Griffith Instruments which was one of the commercial manufacturers of seismographic equipment.

If your interested in building seismological instruments, I can offer tons of advice and also materials for free. Are you located near the San Francisco area?

 

I'm not very close, actually I live in Europe, but I will be thankful for any advice.

 

http://www.infiltec.com/seismo/