Hi Chris,

Thank you very much for the information!   It appears that their is a wide
range of materials that could
be successfully used.

Take care, Meredith

On Wed, Aug 20, 2008 at 7:36 PM,  wrote:

> In a message dated 2008/08/20, paleoartifact@......... writes:
>
> The two separate masses weigh a total of 20 pounds. The absolute maximum
> width of the spring allowed within the clamp is 0.311"; it could obviously
> contain a smaller width ~ 0.25", for much easier insertion / replacement.
>
> As a possible material prelude; I do have 0.007", and 0.014" thick phosphor
> bronze shim roll stock.  I also have 0.010" thick blue tempered hardened
> steel spring shim roll stock.  All old but never used.  All would need
> cutting down and cut edge filing deburring to fit the flat clamp size
> firmly/easily; all the spring widths are more than 0.311".
>
>
>
> Hi Meredith,
>
>        OK. The spring is at about 45 degrees so the stress on the two
> strips will be about 20 lbs, say 10 lbs each. The tensile strength of bronze
> is about 30,000 psi. Hence the absolute minimum strip thickness is about 1.2
> thou. Allowing a safety factor of x10 gives 12 thou.
>
>        Looks like your 14 thou strip would probably do fine.
>
>        Note that you can buy hard rolled bronze weather strip for doors,
> but it is only about 6 thou thick. Hard rolled strip will have about 3x the
> UTS of the soft bronze quoted.
>
>        Note that www.ksmetals.com stock 8 thou phosphor bronze sheet and
> 10 and 18 thou SS strip.
>
>        Regards,
>
>        Chris
Hi Chris,

Thank you very much for the information!   It appears that their is a wide range of materials that could
be successfully used.

Take care, Meredith

On Wed, Aug 20, 2008 at 7:36 PM,  <ChrisAtUpw@.......> wrote:



In a message dated 2008/08/20, paleoartifact@......... writes:






The two separate masses weigh a total of 20 pounds. The absolute maximum width of the spring allowed within the clamp is 0.311"; it could obviously contain a smaller width ~ 0.25", for much easier insertion / replacement.






As a possible material prelude; I do have 0.007", and 0.014" thick phosphor bronze shim roll stock.  I also have 0.010" thick blue tempered hardened steel spring shim roll stock.  All old but never used.  All would need cutting down and cut edge filing deburring to fit the flat clamp size firmly/easily; all the spring widths are more than 0.311".  






Hi Meredith,



       OK. The spring is at about 45 degrees so the stress on the two strips will be about 20 lbs, say 10 lbs each. The tensile strength of bronze is about 30,000 psi. Hence the absolute minimum strip thickness is about 1.2 thou. Allowing a safety factor of x10 gives 12 thou. 






       Looks like your 14 thou strip would probably do fine. 



       Note that you can buy hard rolled bronze weather strip for doors, but it is only about 6 thou thick. Hard rolled strip will have about 3x the UTS of the soft bronze quoted.



       Note that www.ksmetals.com stock 8 thou phosphor bronze sheet and 10 and 18 thou SS strip.



       Regards,



       Chris